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Home My WebLink About2/24/2026City of Diamond Bar Planning Commission Agenda Brian Worthington, Vice Chair Lee, Mao, Commissioner Surendra Mehta, Commissioner Ruben Torres, Commissioner William Rawlings, Commissioner Meeting Date: Tuesday, February 24, 2026 Regular Meeting 6:30 p.m. Diamond Bar City Hall - Windmill Community Room 21810 Copley Drive, Diamond Bar CA 91765 WELCOME TO A MEETING OF THE DIAMOND BAR PLANNING COMMISSION Meetings are open to the public, and you are invited to attend and participate. Agendas for regular Planning Commission meetings are available 72 hours prior to the meeting and are posted in the City's regular posting locations and on the City's website. The Planning Commission may take action on any item listed on the agenda. HOW TO ACCESS THE MEETING REMOTELY Listen -Only: Call +1 (562) 247-8321, Access Code: 591-809-827 Participate: Join Go To Webinar https://attendee.gotowebinar.com/reaister/7098014314851646812 RESOURCES Copies of agendas and agenda packets are on file and available for public inspection in the Planning Division of the Community Development Department at 21810 Copley Drive, Diamond Bar, CA 91765 or online at www.diamondbarca.gov/agendas. For more information about the agendas or rules of the Planning Commission, please email the Community Development Department (commdev@diamondbarca.gov) or call 909-839-7030. AMERICANS WITH DISABILITY ACT ACCOMMODATION In compliance with the Americans with Disabilities Act, if you need special assistance, a disability - related modification or accommodation, agenda materials in an alternative format, or auxiliary aids to participate in this meeting, please email the Community Development Department (commdev@diamondbarca.gov) or call 909-839-7030 as soon as possible. Providing at least 72 hours' notice will help ensure that reasonable arrangements can be made. PUBLIC INPUT The public may provide public comment by attending the meeting in person, by sending an email, or by logging into the teleconference. Please email the Community Development Department (commdev@diamondbarca.gov) by 4:00 p.m. on the day of the meeting and indicate in the Subject Line "FOR PUBLIC COMMENT." Written comments will be distributed to the Planning Commission Member and noted for the record at the meeting. Please note that the meeting will proceed at City of Diamond Bar Planning Commission Page 1 of 328 Diamond Bar Planning Commission Agenda February 24, 2026 Diamond Bar City Hall - Windmill Community Room should comments by teleconferencing become infeasible due to an internet or power outage or due to technical problems outside the City's control. If you wish to make certain that your comments are heard, please attend the meeting in person or send an email by 4:00 p.m. on the day of the meeting/hearing. Speakers are limited to five (5) minutes per agenda item, unless the Chairperson determines otherwise. The Chairperson may adjust this time limit depending on the number of people wishing to speak, the complexity of the matter, the length of the agenda, the hour and any other relevant consideration. Speakers may address the Planning Commission only once on an agenda item, except during public hearings, when the applicant/appellant may be afforded a rebuttal. Any material to be submitted to the Planning Commission at the meeting should be submitted through the Administrative Coordinator. Public comments must be directed to the Planning Commission. A person who disrupts the orderly conduct of the meeting after being warned by the Chairperson or the Chairperson's designee that their behavior is disrupting the meeting may result in the person being removed from the meeting. City of Diamond Bar Planning Commission Page 2 of 328 Diamond Bar Planning Commission Agenda February 24, 2026 1. CALL TO ORDER: 6:30 p.m., Windmill Room PLEDGE OF ALLEGIANCE: ROLL CALL: Commissioners Torres, Rawlings, Mehta, Mao, Vice Chair Worthington APPROVAL OF AGENDA: Vice Chair 2. PUBLIC COMMENTS: "Public Comments" is the time reserved on each regular meeting agenda to provide an opportunity for members of the public to directly address the Planning Commission on Consent Calendar items or other matters of interest not on the agenda that are within the subject matter jurisdiction of the Planning Commission. Although the Planning Commission values your comments, pursuant to the Brown Act, members of the Planning Commission may briefly respond to public comments if necessary, but no extended discussion and no action on such matters may take place. There is a five-minute maximum time limit when addressing the Planning Commission. 3. CONSENT CALENDAR: All items listed on the Consent Calendar are considered by the Planning Commission to be routine and will be acted on by a single motion unless a Planning Commission Member or member of the public request otherwise, in which case, the item will be removed for separate consideration. 3.1 February 10, 2026 Planning Commission Meeting Minutes Recommended Action: Staff recommends the Planning Commission approve the February 10, 2026, Planning Commission meeting minutes as received. 3.2 2025 General Plan Status Report Recommended Action: Approve the report and forward it to the City Council to receive and file. 4. OLD BUSINESS: 5. NEW BUSINESS: 6. PUBLIC HEARINGS: 6.1 Development Code Amendment No. PL2024-51 (Objective Design Standards) Environmental Assessment: On December 17, 2019, the Diamond Bar City Council certified Final EIR (No. SCH 2018051066) for the Diamond Bar 2040 General Plan and Climate Action Plan. In 2022, the City adopted the 2021-2029 Housing Element Update and concurrently amended the General Plan 2040 Land Use and Economic Development Element. The potential impacts of the 2021-2029 Housing Element Update and concurrent Land Use and Economic Development Element amendment were determined to be within the scope of the City of Diamond Bar Planning Commission Page 3 of 328 Diamond Bar Planning Commission Agenda February 24, 2026 Certified EIR. The City concluded that neither a subsequent nor a supplemental EIR was required. Accordingly, the City adopted Addendum No. 1 to the Certified EIR on August 1 1, 2022. The draft ODS anticipates residential and mixed -use development consistent with the assumptions in the 2040 General Plan and analyzed in the General Plan EIR. CEQA Guidelines Section 15164(a) states: "The lead agency or responsible agency shall prepare an addendum to a previously certified EIR if some changes or additions are necessary but none of the conditions described in Section 15162 calling for preparation of a subsequent EIR have occurred." Pursuant to CEQA Guidelines Section 15164, the City has prepared Addendum No. 2 to the General Plan EIR (Attachment 2), which demonstrates that adoption of the ODS would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts analyzed in the Certified EIR for the City General Plan 2040. In addition, the information throughout the addendum affirms that there is no new information of substantial importance that was previously unknown and is now available. Therefore, a subsequent EIR would not be required pursuant to Section 15162 of the State CEQA Guidelines. The City has thus determined an addendum to the previously Certified EIR to be the appropriate environmental compliance document for the proposed project. Recommended Action: Adopt the attached resolution recommending the City Council approve Development Code Amendment No. PL2024-51, amending Title 22 of the Diamond Bar City Code (DBCC), adding Chapter 22.19 to establish multifamily and mixed -use residential ODS. 7. PLANNING COMMISSION COMMENTS/INFORMATION ITEMS: S. STAFF COMMENTS/INFORMATIONAL ITEMS: 8.1 Project Status Report Recommended Action: Staff recommends the Planning Commission receive and file the Project Status Report dated February 24, 2026. 9. SCHEDULE OF FUTURE EVENTS: 9.1 City Council Meeting - March 3, 2026 - 6:30 p.m., online teleconference and SCAQMD Main Auditorium, 21865 Copley Dr. 9.2 Planning Commission Meeting - March 10, 2026 - 6:30 p.m., online teleconference and City Hall Windmill Room, 21810 Copley Dr. - Cancelled 9.3 City Council Meeting - March 17, 2026 - 6:30 p.m., online teleconference and SCAQMD Main Auditorium, 21865 Copley Dr. 9.4 Planning Commission Meeting - March 24, 2026 - 6:30 p.m., online teleconference and City Hall Windmill Room, 21810 Copley Dr. 9.5 City Council Meeting - April 7, 2026 - 6:30 p.m., online teleconference and SCAQMD Main Auditorium, 21865 Copley Dr. City of Diamond Bar Planning Commission Page 4 of 328 Diamond Bar Planning Commission Agenda February 24, 2026 10. ADJOURNMENT: CERTIFICATION I, Arlene Laviera, Administrative Coordinator, City of Diamond Bar, hereby certify, under penalty of perjury under the laws of the State of California that the foregoing notice was posted pursuant to Government Code Section 54950 Et. Seq., not less than 72 hours prior to the meeting, at the following locations: Diamond Bar City Hall Kiosk, Diamond Bar City Hall Bulletin Board, City website: www.diamondbarca.gov, and Diamond Bar Library. Arlene Laviera Administrative Coordinator Date Posted: February 19, 2026 City of Diamond Bar Planning Commission Page 5 of 328 Agenda Item #: 3.1 Meeting Date: February 24, 2026 PLANNING COMMISSION AGENDA REPORT TO: Chair and Members of the Planning Commission FROM: Greg Gubman, Community Development Director SUBJECT: February 10, 2026 Planning Commission Meeting Minutes RECOMMENDATION: Staff recommends the Planning Commission approve the February 10, 2026, Planning Commission meeting minutes as received. BACKGROUND/DISCUSSION: Minutes have been prepared and are being presented for approval. PREPARED BY: Arlene Laviera, Administrative Coordinator, Community Development ATTACHMENTS: 02-10-26 pcmin Page 6 of 328 MINUTES OF THE CITY OF DIAMOND BAR REGULAR MEETING OF THE PLANNING COMMISSION February 10, 2026 1. CALL TO ORDER: AC/Torres called the meeting to order at 6.30 p.m. in the Windmill Community Room, 21810 Copley Drive, Diamond Bar, CA 91765. PLEDGE OF ALLEGIANCE: Mao ROLL CALL: Mehta, Torres, Mao ABSENT: Rawlings, Worthington STAFF PRESENT: Greg Gubman, Community Development Director, Grace Lee, Planning Manager, Hal Ghafari, Public Works Manager/Assistant City Engineer, Neal Payton, Consultant, Marie Campbell, Consultant, Arlene Laviera, Administrative Coordinator; Ricia R. Hager, Assistant City Attorney and Michael Daudt, Assistant City Attorney. 2. PUBLIC COMMENTS: None. 3. CONSENT CALENDAR: 3.1 MINUTES OF THE PLANNING COMMISSION REGULAR MEETING — November 25, 2025. Mao moved, and Mehta seconded to approve consent calendar. Motion carried 3-0-0- 2 by the following Roll Call vote: AYES: 3 COMMISSIONERS: Mao, Mehta, A/C Torres NOES: 0 COMMISSIONERS: None ABSTAIN: 0 COMMISSIONERS: None ABSENT: 2 COMMISSIONERS: Rawlings, Worthington 4. OLD BUSINESS: 5. NEW BUSINESS: 6. PUBLIC HEARING: 6.1 Town Center Specific Plan: The proposed Diamond Bar Town Center Specific Plan ("TCSP" or "Project") establishes a comprehensive regulatory framework to guide the transformation of approximately 45 acres of existing suburban -style retail centers into a pedestrian -oriented, mixed -use downtown, or "Town Center." The Specific Plan provides for a mix of residential, commercial, hotel, entertainment, and public open space uses, supported Page 7 of 328 February 10, 2026 PAGE 2 PLANNING COMMISSION by form -based development standards intended to shape building scale, massing, and transitions adjacent to existing neighborhoods. At buildout, the TCSP would allow development of up to 2,055 residential units, 200 hotel rooms, approximately 446,000 square feet of commercial space, and 40,000 square feet of public open space. Compared to development assumptions under the General Plan (as amended by the 2022 Housing Element Update), the Project increases residential capacity and open space while reducing overall commercial square footage. Environmental review has been completed through a Final Supplemental EIR (Final "SIR") prepared as a supplement to the previously certified General Plan EIR, including a subsequent Addendum adopted for the 2021-2029 Housing Element Update. The Final SIR identifies significant and unavoidable impacts related to air quality and transportation (vehicle miles traveled). A Statement of Overriding Considerations has been prepared to weigh the Project's unavoidable environmental effects against a series of economic, social, planning, and legal benefits supported by substantial evidence in the record. Required Legislative Actions In addition to adopting the TCSP regulatory document, concurrent legislative actions include a General Plan Amendment and zoning map and text amendments. These actions align the General Plan land use designations and zoning with the Town Center Specific Plan to ensure internal consistency and to implement the Specific Plan's land use framework. The Planning Commission's role is advisory. In other words, the Commission is asked to evaluate the policy framework of the Specific Plan, its consistency with adopted plans, and the adequacy of the environmental review, and to forward a recommendation to the City Council. Enactment of the TCSP requires the following discretionary actions: 1. Adoption of the Diamond Bar Town Center Specific Plan; 2. Adoption of a General Plan Amendment; 3. Adoption of zoning map and zoning text amendments; and 4. Certification of the Final Supplemental EIR, adoption of Findings of Fact and Statement of Overriding Considerations, and adoption of the Mitigation Monitoring and Reporting Program. The two attached resolutions drafted for the Planning Commission's consideration incorporate recommended actions for the City Council to consider at an upcoming hearing. Environmental Assessment: In accordance with the California Environmental Quality Act (CEQA), the City, as Lead Agency, prepared a Supplemental Environmental Impact Report (SIR) to evaluate the potential environmental impacts associated with adoption and implementation of the TCSP and related legislative actions. The SIR was prepared as a supplement to the previously Page 8 of 328 February 10, 2026 PAGE 3 PLANNING COMMISSION certified Diamond Bar General Plan 2040 and Climate Action Plan Program Environmental Impact Report (State Clearinghouse No. 2018051066), which was certified by the City Council on December 17, 2019, and as subsequently addended in conjunction with adoption of the City's 2021-2029 Housing Element on August 11, 2022. The City determined that an SIR was the appropriate environmental document because the Town Center Specific Plan represents a refinement and implementation of the General Plan land use framework for a defined Planning Area, and because the certified General Plan EIR and Housing Element Addendum provide relevant program -level environmental analysis. The SIR focuses on those environmental topics where additional project -specific analysis was warranted and relies on the prior EIR and addenda where impacts were previously analyzed and remain adequately addressed. Environmental Review Process and Public Participation On June 5, 2023, the City issued a Notice of Preparation (NOP) to solicit comments regarding the scope and content of the SIR. The NOP was circulated to the State Clearinghouse, responsible and trustee agencies, and interested parties; published in the San Gabriel Valley Tribune; mailed to property owners and business owners within a 1,000-foot radius of the Planning Area; and distributed electronically to individuals subscribed to receive Town Center updates. The NOP was circulated for a 30-day public review period. As part of the scoping process, the City held a public scoping meeting on June 8, 2023, at Diamond Bar City Hall, during which verbal comments were received from members of the public and considered in preparation of the Draft SIR. Written comments were also received from public agencies and individuals and were incorporated where appropriate into the environmental analysis. Following completion of the Draft SIR, the City filed a Notice of Completion with the State Clearinghouse and a Notice of Availability with the Los Angeles County Clerk of the Board. The Draft SIR was circulated for a State -mandated 45-day public review period, which ran from August 25, 2025, through October 10, 2025. Notice of availability was published in the San Gabriel Valley Tribune, mailed to approximately 910 property owners, business owners, agencies, and interested parties, and distributed electronically to subscribers. During the public review period, the Draft SIR was made available for review on the City's dedicated Town Center website (www.downtown4db.com) and in hard copy at Diamond Bar City Hall and the Diamond Bar Public Library. The City received written comment letters and emails from public agencies, organizations, and members of the public during the review period. Final Supplemental EIR Following the close of the public review period, the City prepared a Final Supplemental EIR, Page 9 of 328 February 10, 2026 PAGE 4 PLANNING COMMISSION which includes the Draft SIR, all written comments received during the public review period, responses to those comments, and minor revisions and clarifications to the Draft SIR where appropriate. The Final SIR does not identify any new significant impacts beyond those disclosed in the Draft SIR and reflects the City's independent judgment and analysis as Lead Agency. The Final SIR, together with the Mitigation Monitoring and Reporting Program (MMRP) and the Findings of Fact and Statement of Overriding Considerations (discussed in detail below), has been made available for public review on the Town Center website and in hard copy at City Hall and the Diamond Bar Public Library in advance of the Planning Commission hearing. Environmental Impacts The Final SIR concludes that most environmental impacts would be less than significant or mitigated to a less -than -significant level. Significant and unavoidable impacts remain in the areas of air quality and transportation (vehicle miles traveled), consistent with CEQA Guidelines Section 15064.3. Statement of Overriding Considerations Because the Final Supplemental EIR identifies significant and unavoidable impacts related to air quality and transportation (vehicle miles traveled), approval of the Town Center Specific Plan would require adoption of a Statement of Overriding Considerations pursuant to CEQA Guidelines Section 15093. As documented in the Statement of Overriding Considerations prepared for the Project, the City Council will be asked to weigh the Project's unavoidable environmental effects against a series of economic, social, planning, and legal benefits supported by substantial evidence in the record. These benefits include, but are not limited to, the following: • Implementation of the City's Housing Element Commitments and RHNA Obligations. The Specific Plan implements the City's certified 2021-2029 Housing Element by rezoning the Town Center to permit residential development at a base density of 30 dwelling units per acre and by establishing an Inclusionary Point System that incentivizes the production of affordable housing. The Town Center represents one of the City's primary opportunity sites for accommodating its assigned Regional Housing Needs Allocation across multiple income categories. • Generation of Long -Term Fiscal Benefits to the City. The fiscal analysis prepared for the Town Center projects that redevelopment under the Specific Plan would result in a substantial positive net fiscal impact to the City's General Fund, driven by increased property tax, sales tax, and transient occupancy tax revenues. These revenues would support essential municipal services and represent a significant improvement Page 10 of 328 February 10, 2026 PAGE 5 PLANNING COMMISSION over the existing underutilized commercial condition of the site. • Implementation of the Community's Longstanding Vision for a Town Center. The Specific Plan translates the community vision established through the General Plan 2040 and subsequent public engagement into an implementable regulatory framework. The Plan reflects extensive public outreach, including workshops, study sessions, and a design charrette, and establishes form -based standards to guide future development consistent with that vision. • Consistency with Expert Planning and Urban Design Recommendations. The Specific Plan incorporates recommendations from the ULI-LA TAP, which concluded that higher residential densities, a coordinated street grid, and pedestrian -oriented design are necessary to create a viable and successful Town Center environment. • Leveraging Unique Site Characteristics and Regional Accessibility. The Plan capitalizes on the site's topography, regional freeway access, and proximity to major employment centers to create a mixed -use destination with sufficient scale to support housing, retail, dining, and public spaces in a manner not achievable under existing zoning. Response to Documented Market Demand. The market analysis demonstrates long-standing unmet demand for housing and mixed -use development in Diamond Bar. The Specific Plan responds to this demand by providing new housing opportunities for a range of household types while supporting a critical mass of residents and visitors necessary to sustain a Town Center. Ultimately, the City Council will need to determine whether these benefits, considered individually and collectively, provide the basis to determine that the Project's unavoidable environmental impacts are acceptable in light of the Project's overall benefits. Mitigation Monitoring and Reporting Program A Mitigation Monitoring and Reporting Program has been prepared to ensure implementation of all applicable mitigation measures identified in the Final SIR. Recommended Action: 1. Adopt the attached Resolution (Attachment 1) recommending that the City Council certify the Final SIR, adopt the Findings of Fact and Statement of Overriding Considerations; and 2. Adopt the attached Resolution (Attachment 2) recommending that the City Council adopt the Town Center Specific Plan and corresponding General Plan Amendment, Development Code Amendment and Zoning Map Amendment. Page 11 of 328 February 10, 2026 PAGE 6 PLANNING COMMISSION CDD/Gubman presented the staff report. Recess taken at 7:10 p.m. to address technical issues with audio. The Planning Commission reconvened at 7:15 p.m. AC/Torres opened the public hearing. The following provided public comments: Mario Del Hoya, resident, expressed concerns regarding traffic, parking, and safety of the children that attend nearby schools. One other concern is that his solar panels will be blocked depending on the size of the buildings within the Town Center. Mao moved, Mehta seconded to adopt Resolution Nos. 2026-01, and 2026-02 recommending that the City Council certify the Final SIR, adopt the Findings of Fact and Statement of Overriding Considerations; and adopt the Town Center Specific Plan, corresponding General Plan Amendment, Development Code Amendment and Zoning Map Amendment subject to the conditions of approval. Motion carried 3-0-0-2 by the following Roll Call vote: AYES: 3 COMMISSIONERS: Mao, Mehta, A/C Torres NOES: 0 COMMISSIONERS: None ABSTAIN: 0 COMMISSIONERS: None ABSENT: 2 COMMISSIONERS: Rawlings, Worthington 7. PLANNING COMMISSION COMMENTS/INFORMATION ITEMS: E:�•'�/_1a&fie]►ViILy,14►k&111►1.101VIVi/_110Eel ZF_1N194Ly,6*5 CDD/Gubman informed the Planning Commission that on February 24, 2026, staff is presenting the Citywide Objective Design Standards. 9. SCHEDULE OF FUTURE EVENTS: As noted in the agenda. 10. ADJOURNMENT: With no further business before the Planning Commission, AC/Torres adjourned the Regular Planning Commission meeting at 7:49 p.m. Page 12 of 328 February 10, 2026 PAGE 7 PLANNING COMMISSION The foregoing minutes are hereby approved this loth day of February, 2026. Ruben Torres, Acting Chairperson Attest: Respectfully Submitted, Greg Gubman, Community Development Director Page 13 of 328 Agenda Item #: 3.2 Meeting Date: February 24, 2026 PLANNING COMMISSION AGENDA REPORT TO: Chair and Members of the Planning Commission FROM: Greg Gubman, Community Development Director SUBJECT: 2025 General Plan Status Report RECOMMENDATION: Approve the report and forward it to the City Council to receive and file. BACKGROUND/DISCUSSION: State Law requires each city to prepare and adopt a comprehensive, long-term General Plan to guide its physical development. The General Plan is a policy document comprised of goals and policies for implementation. In the fall of 2016, the City embarked on a comprehensive update to the General Plan to create a community vision and blueprint for the City through 2040. The City Council adopted Diamond Bar General Plan 2040 on December 17, 2019. In accordance with California Government Code Section 65400(b), the City is required to submit an annual General Plan status report to the local legislative body (City Council), the State Governor's Office of Planning and Research (OPR), and State Department of Housing and Community Development (HCD) on the status of the General Plan, its implementation progress, and how the City is meeting the region's housing needs. The attached report lists the City's progress toward the implementation of the General Plan for the period of January 1, 2025 to December 31, 2025. The Planning Commission is asked to review the annual report and forward a recommendation to the City Council for its consideration as the legislative body responsible for administering the General Plan. Once accepted by the City Council, the report will be submitted to OPR and HCD. This report is due to HCD by April 1, 2026. Major accomplishments during this period include the following: General Plan Amendment, Development Code Amendment, and Zone Change for Housing Element Implementation: As part of the City's implementation of the City's Certified Housing Element, the City rezoned the General Plan's three Mixed -Use designations (Town Center Mixed -Use, Neighborhood Mixed -Use and Transit -Oriented Mixed -Use focus areas) to allow residential development at a minimum density of 20 dwelling units per acre and a maximum density of at least 30 dwelling units per acre. The amendments to the General Plan, Development Code and Zoning Map implemented General Plan Goals and Policies LU-G-4, LU-G-7, LU-G-12, LU-G-15, LU-G-18, LU-P-23, LU-P-29, LU-P-35, and Housing Element Program H-8 of the 2021-2029 City's Certified 2001-2029 Housing Element. Page 14 of 328 Agenda Item #: 3.2 Meeting Date: February 24, 2026 Diamond Bar PONY Baseball Stevens Field Property: The 10.23-acre property located at 22601 Sunset Crossing Road was transferred to the City at no cost by a Transfer Agreement Facilities Use Agreement. This property combined with the adjacent City -owned 2.78-acre site will create a 13-acre park site that has the potential to be developed into a community park with amenities for residents of all ages, interests and activity levels. However, funding to construct a new park on the property has not been secured, and the cost is estimated to exceed $20 million. Upon completion of the property transfer, the City invested approximately $1 million to improve playability on three of the four existing fields, remove existing hazards, and complete basic maintenance of existing trees and landscaping. By restoring the site's playability, the City will be able to provide additional capacity for a variety of Diamond Bar youth and adult sports, including baseball, softball, soccer and football, among others, ultimately reducing existing allocation impacts on community facilities such as Pantera and Peterson parks. This transfer implemented General Plan Policies PF-P-17 and CHS-P-1. Sustainability/Environmental Services: The City has been actively working to reduce waste and increase diversion under the new waste hauler contracts that began in September 2025. During the transition to the new contracts, the City and its waste haulers implemented an education and outreach campaign to re-educate residents on proper sorting practices to increase diversion and reduce contamination. Outreach efforts included print and electronic materials, in -person and virtual workshops, and ongoing contamination monitoring. The City also continues to provide waste reduction tips through its monthly electronic environmental newsletter. In addition to its ongoing student education programs with Discovery Cube that focus on recycling and waste reduction, the City partnered with Algalita Marine Research to offer an additional educational experience for youth, focused on plastic pollution and prevention strategies. These services implemented General Plan Goal CHS-G-14. Keep It Local: Shop Diamond Bar First Campaign: The City officially launched the campaign to shop in Diamond Bar. New businesses get a free ribbon -cutting ceremony when they open their doors for the first time, celebrate a major milestone, or complete a major improvement or renovation project. The program also provides businesses with free exposure and marketing through social media content, short highlight videos, and a month -long incentive that encourages people to shop or dine with them for 10% back in rewards through the Open Rewards: Shop Local app. This initiative implements General Plan Policy LU-P-13. Diamond Bar TV: The City expanded improvements in communication by making the City's government access channel, Diamond Bar TV (DBTV) available for free streaming on Roku and the Cablecast application. Previously only available on Spectrum Cable Channel 3 or Frontier FiOS television Channel 47, DBTV is one of the many ways the City shares information about City programs, projects and services with the community. Programming on DBTV include city council meeting replays, local business spotlights, public safety videos, and the DB Minute video shorts services that covers various City services and programs. This project implemented General Plan Policy CHS-P-30. Diamond Bar Boulevard Complete Streets Project: The Diamond Bar Boulevard Complete Streets Project is a comprehensive, multi -modal infrastructure project that advances the City's General Plan 2040 vision for a vibrant, pedestrian -oriented Town Center. Located along Diamond Bar Boulevard between Golden Springs Drive and Palomino Drive, this project implements complete street and right- of-way improvements consistent with the Town Center Specific Plan, including enhanced pedestrian and bicycle facilities, stormwater treatment features, and decorative streetscape elements. Over several years, City staff successfully secured a diverse mix of external funding from federal, state, and Page 15 of 328 Agenda Item #: 3.2 Meeting Date: February 24, 2026 regional sources, positioning the project for construction while minimizing local financial impact. This project represents the first phase of future Town Center improvements and establishes a foundation for long-term mobility, placemaking, and economic vitality along Diamond Bar Boulevard, and implements General Plan Goals and Policies: LU-P-5, CC-G-5, CC-P-2, CC-P-5, CC-P-21, CR-G-2, CR-P-1, CR-P-3, CR-P-4, CR-P-17, CR-P-39, CR-P-44, and PS-P-13. Maple Hill Park Improvements Project: This project represents a major reinvestment in aging park infrastructure to enhance recreational amenities, accessibility, and user experience. The Project includes the replacement of an outdated playground, construction of a new prefabricated restroom building, and comprehensive Americans with Disabilities Act (ADA) improvements to the playground area, restroom facilities, and adjacent pedestrian pathways connecting to the parking lot. These upgrades ensure compliance with current accessibility standards while significantly improving public safety and usability. The City successfully secured a $660,000 State Parks Grant to support project funding, leveraging external resources to modernize this community asset. This project implemented General Plan Goals and Policies: LU-P-5, CHS-G-3, CHS-P-1, and CHS-P-59. A complete summary matrix of the City's progress toward implementing the General Plan is provided in Attachment A. PREPARED BY: Grace S. Lee, Planning Manager ATTACHMENTS: 2025 GP Status Report Matrix Page 16 of 328 City of Diamond Bar General Plan Status Report 2025 Period beginning January 1, 2025, and ending December 31, 2025 DIAMOND BAR GENERAL PLAN 2040 OVERVIEW On December 17, 2019, the City Council adopted Diamond Bar General Plan 2040, which is a State mandated document that the City uses to plan the framework for its future physical, social, and economic development. The General Plan is considered a long-term document that projects development within a community for approximately 20 years. The General Plan serves as the foundation for all land use decisions and provides a vision and blueprint about how a community will grow, reflecting community priorities and values while shaping the future. The City of Diamond Bar General Plan consists of the following eight elements ("Chapters"): 1) Land Use & Economic Development 2) Community Character & Placemaking 3) Circulation 4) Resource Conservation 5) Public Facilities & Services 6) Public Safety 7) Community Health & Sustainability 8) Housing The following information summarizes the status of the goals and policies that the City has implemented for each chapter of the updated General Plan in 2020. Each chapter is organized by color scheme for navigation. 1. Land Use & Economic Development POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT GENERAL Goals To bring Diamond Bar into compliance with State law, as well as implement its Housing Element Programs, the City must formulate solely objective standards to govern the design of the multi -family In areas planned to accommodate new growth, ensure quality residential and mixed -use projects. On June 4, 2024, a consultant LU-G-3 Land Use design that makes a positive contribution to the character of services agreement with Torti Gallas + Partners was awarded to Community Diamond Bar. prepare the Citywide Objective Design Standards (ODS). In 2025, Development staff made significant progress reviewing numerous versions of the draft ODS and the final document is ready for Planning Commission and City Council consideration and is tentatively scheduled for the February 24, 2026 Planning Commission hearing. In June 2022, the City kicked off the preparation of the Town Center Specific Plan (TCSP) for the Town Center Mixed -Use focus area. Locate new residential growth in or adjacent to mixed -use centers The TCSP will provide the regulatory and urban design framework LU-G-4 Land Use and transit stations to support regional and statewide efforts to to establish a downtown, or "Town Center" in Diamond Bar as a Community encourage sustainable land use planning and smart growth walkable place with entertainment, retail, restaurants community Development principles. gathering spaces and urban housing opportunities. The 45-day public review period for the Supplemental SIR was August 25 through October 10, 2025. On February 10, 2026, the Planning Page 1 of 50 Page 17 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT Policies LU-P-1 LU-P-4 LU-P-5 Land Use Land Use Land Use Ensure that the scale and massing of new development provides sensitive transitions or design techniques in building height, bulk, and landscaping to minimize impacts on adjacent, less intensive uses, particularly residential uses. Monitor and evaluate potential impacts of proposed adjacent, local, and regional developments to anticipate and require mitigation to the greatest extent feasible to reduce land use, circulation, and economic impacts on Diamond Bar. Ensure that adequate public services, facilities, and infrastructure are available or provided to support new development, including water, wastewater, stormwater, solid waste, transportation, public safety, and parks. Commission recommended approval to the City Council, and is tentatively scheduled for the March 3, 2026 City Council hearing. On February 4, 2025, the City rezoned the General Plan's three Mixed -Use designations (Town Center Mixed -Use, Neighborhood Mixed -Use and Transit -Oriented Mixed -Use focus areas) to allow residential development at a minimum density of 20 dwelling units per acre and a maximum density of at least 30 dwelling units per acre, as part of the City's implementation of the City's Certified Housing Element. See Land Use Chapter Goal LU-G-3. In October 2025, the Pomona Unified School District published a draft Initial Study/Mitigated Negative Declaration (IS/MND) for the Diamond Ranch High School Solar Farm Project, in preparation for the construction and operation of a 2.8-megawatt direct current solar photovoltaic (PV) power generating system, which would include supporting structures, inverter modules, pad -mounted transformers, access roads and fencing, and a 480-volt switchgear station. A total of 4,284 PV panels would be installed on ground -mounted racks. The renewable energy generated by the project would be distributed to the existing Southern California Edison (SCE) distribution line located beneath Diamond Ranch Road and exported to SCE's grid to offset electricity use at 20 District -owned properties. The project would generate 2.8 megawatts of electricity per year, which equates to approximately 20 percent of the District's annual energy use. The City reviewed the draft IS/MND and had no comments. Safe, Clean Water Program (Measure W) Staff prepared and submitted the City's Measure W Annual Plan to the County of Los Angeles. The Annual Plan outlined the City's proposed Measure W expenditures for the fiscal year, including CIP projects, routine maintenance, consultant costs, efforts to pursue grant funding, and staff time. As a result, Diamond Bar received its local return of over $850K for FY2024-25. Community Development Community Development Public Works Page 2 of 50 Page 18 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Stormwater Quality Improvement Projects In 2025, the City completed the construction for the Grand Avenue and Golden Springs Drive Intersection Improvements Project, which features drainage infrastructure to improve stormwater quality. Parks and Facility Projects In January 2025, the construction of the Diamond Bar Center Air Conditioner Replacement and Air Quality Upgrades Project was completed. The scope of this project included the replacement of the HVAC system at the Diamond Bar Center, which improved reliability, efficiency, and improved indoor air quality. In September 2025, the construction of the Pantera Park Hard Court Rehabilitation and LED Lighting Retrofit Project was completed. The scope of this project included the resurfacing of the existing basketball and tennis courts, rehabilitating the sports equipment, and retrofitting site illumination to LED lighting. In October 2025, the construction of the Maple Hill Park Improvements Project was completed. The scope of this project included the replacement of the restroom building, playground equipment, and site accessibility improvements. In November 2025, the construction of the City Hall Cable Channel Broadcast and Audio -Visual Equipment Upgrade Project was completed. The scope of this project included the upgrade of the A/V technology inside the Windmill Room at City Hall, which is now capable of streaming various City meetings and events through enhanced cameras and audio capturing equipment. See Community Character & Placemaking Chapter Policy CC-G-5 for the update on the Diamond Bar Boulevard Complete Streets Corridor Project. When appropriate, require new development to pay its fair share of The City requires all new development projects to pay their fair share LU-P-6 Land Use the public facilities and off -site improvements needed to serve the of public improvements, including impact fees for parks, sewer, and Public Works proposed use. traffic (when applicable). LU-P-7 Land Use As larger vacant or underutilized sites within the built environment The Town Center Specific Plan (see Goal LU-G-4 above) will Community are developed or redeveloped, maximize multimodal accessibility establish a fine-grained street and block grid to encourage Development Page 3 of 50 Page 19 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT with appropriately designed street networks, and walkable block pedestrian and bicycle circulation, and improved connectivity sizes scaled to proposed uses. between the east and west sides of Diamond Bar Boulevard. RESIDENTIAL Goals The City has been processing new ADUs in accordance with State laws and continues to encourage ADUs and Junior ADUs, which provide an affordable housing option for lower income households. In 2025, 51 building permits for ADUs were issued. The City is in the early testing phase of its Pre -Approved Accessory Dwelling Unit (ADU) Program, known as DBADU, which supports the City's General Plan housing goals by streamlining ADU development and expanding housing opportunities. The program is implemented pursuant to State ADU law, including Government Code Sections Promote a variety of housing and neighborhood types that respond 65852.2 and 65852.22, which require ministerial approval of ADUs Community LU-G-7 Land Use to a range of income, household sizes, and accessibility levels. that comply with objective standards and encourage jurisdictions to Development reduce regulatory barriers to ADU construction. The DBADU program allows qualified design professionals to submit ADU plans for City review and pre -approval, with the intent of creating a catalog of code -compliant designs that homeowners may use to reduce permitting time and uncertainty. In December 2025, in order to support implementation, City staff has developed a dedicated program website and application materials, and the City is currently piloting the program with a selected firm to test workflows and review procedures before opening participation to additional professionals and releasing pre -approved plans for broader public use. Policies All new residential development requires review and approval by the Planning Commission through a Development Review application process to assess a project's compatibility, architectural design, size, scale and massing with the neighborhood. The Planning Ensure that new residential development be compatible with the Commission reviews the design to ensure compliance with the City's prevailing character of the surrounding neighborhood in terms of General Plan policies and design guidelines, and to minimize Community LU-P-8 Land Use building scale, density, massing, and design. Where the General adverse effects of the proposed project upon the surrounding Development Plan designates higher densities, provide adequate transitions to properties and the City in general. In compliance with recent existing development. legislation, the City has begun the process of formulating objective design standards for residential development, beginning with the drafting of the Town Center Specific Plan regulatory document, and have embarked on the preparation of Citywide objective design standards. Page 4 of 50 Page 20 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT LU-P-9 LU-P-10 Land Use Land Use COMMERCIAL, OFFICE, AND INDUSTRIAL Goals LU-G-11 Policies LU-P-13 110130C! Land Use Land Use Land Use Incorporate architectural and landscape design features in new development that create more pedestrian -friendly neighborhoods, such as orientation to the street; set -back, or detached garages; tree -lined streets; and landscaped parkways between streets and sidewalks. Provide opportunities for and incentivize the development of housing types that are affordable to all segments of the Diamond Bar community, including senior housing and independent assisted living facilities, residential care facilities, and rental and for -sale housing units affordable to low and moderate -income households. Support existing commercial centers by encouraging ongoing investment and, where appropriate, reuse and redevelopment. Promote the revitalization of existing neighborhood commercial centers by encouraging property owners to maintain and improve the appearance of individual buildings and commercial centers through building fagade improvements, landscaping, and pedestrian improvements. Improve vehicular accessibility, traffic flow, and parking availability as well as pedestrian and bicycle access and amenities within office, commercial, and industrial areas. Through the development review process, all new development is reviewed to promote high functional and aesthetic architectural and landscape standards to complement and add to the economic, physical, and social character of Diamond Bar. On January 16, 2025, pursuant to SB 35, the City approved the development of a 44-unit multi -family residential project located at 2235 Morning Canyon Road. The project would provide 36 market - rate units, four very low-income units, and four moderate income units. Plans were submitted for plan check in the Summer of 2025. In 2025, the City approved three Conditional Use Permits for a Pilates studio, a Type 21 alcohol license at a gas station, and a banquet. All three businesses have occupied an existing tenant space, thereby encouraging ongoing investment of the existing commercial centers. In addition, 196 new business licenses were issued in 2025. In Spring 2025, the City officially launched a Business Recognition Program, a new component to the Keep it Local: Shop Diamond Bar First campaign. As part of this program, Diamond Bar businesses get a free ribbon -cutting ceremony when they open their doors for the first time, celebrate a major milestone, or complete a major improvement or renovation project. Beyond these ceremonies, the program also provides businesses with free exposure and marketing through social media content, short highlight videos, and a month- long incentive that encourages people to shop or dine with them for 10% back in rewards through the Open Rewards: Shop Local app. Created in 2024, the Keep it Local: Shop Diamond Bar First campaign aims to highlight and celebrate the many and varied small businesses located in town and encourage more people to make shopping locally a year-round priority. In 2025, the businesses that took part in the recognition program were Popeyes, Certified Federal Credit Union, Tacitas Coffee, Hikari Sushi, and Klatch Coffee. During project review, staff ensures that all office, commercial, and industrial areas provide improved vehicular accessibility, traffic flow, and parking availability as well as review for opportunities to incorporate pedestrian and bicycle access and amenities. Community Development Community Development Community Development City Manager's Office and Community Relations Division Community Development Page 5 of 50 Page 21 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Public Works Adaptive Traffic Control System The City's Adaptive Traffic Control System (ATCS) was deployed in 2020 and continues to adapt based on actual traffic demands. The system accommodates construction projects of various durations and other traffic -impacting activities to promote circulation along the City's arterial roadways. Traffic Signal Battery Back -Up Systems All of the City's maintained traffic signals feature a battery backup system (BBS) that helps extend operations amid power disruptions. The BBS hardware was proven to be useful amid the multiple outages and Public Safety Power Shutoff (PSPS) events throughout 2025, as traffic circulation was minimally compromised because of the backup power source available to extend the operations of impacted traffic signals. In 2025, as part of the annual Capital Improvement Program, the City replaced the BBS units at several intersections to ensure that the hardware is ready for use with future outage events as planned. SR57/60 Confluence Project The construction of the SR57/60 Confluence Project continued in 2025. The construction of the SR57 northbound overpass bridge extension improvements above Golden Springs Drive were completed. Also, the construction of the new northbound SR57 ramps at Grand Avenue were completed. Throughout all phases of this project, the City is collaborating with the San Gabriel Valley Council of Governments (SGVCOG) and contractors to manage traffic flow affected by the various stages of construction. The project is scheduled for completion in 2028. See Community Character & Placemaking Chapter Goal CC-G-5 for update on the Diamond Bar Boulevard Complete Streets Project. MIXED USE IF Goals — General Encourage compact mixed -use developments and projects that are LU-G-12 Land Use walkable, designed to encourage community interaction, and fulfill See Land Use Chapter Goal LU-G-4. Community a diversity of local commercial, employment, housing, and Development recreational needs. Page 6 of 50 Page 22 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT LU-G-13 Land Use Maximize multi -modal accessibility to and connectivity within See Land Use Chapter Goal LU-P-7. Community mixed -use areas. Development Foster development of nodes or clusters of mixed -use centers to LU-G-14 Land Use promote city and neighborhood identity, improve accessibility to See Land Use Chapter Goal LU-G-4. Community stores, parks, natural open spaces, and services, and promote Development walkable, pedestrian -scaled retail and dining destinations. Goals — Town Center Mixed Use Promote and support the commercial area on both sides of Diamond Bar Boulevard from Golden Springs Drive to SR-60 as a Community LU-G-22 Land Use vibrant, pedestrian -oriented Town Center that serves as Diamond See Land Use Chapter Goal LU-G-4. Development Bar's primary specialty retail and dining destination and is accessible to all Diamond Bar residents. LU-G-23 Land Use Ensure an inviting and comfortable public realm to encourage See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Community pedestrian activity in the Town Center area. Development LU-G-24 Land Use Allow residential and office uses as secondary to commercial (retail, See Land Use Chapter Goal LU-G-4. Community dining, and entertainment) uses. Development Policies — General LU-P-17 Land Use Promote site designs that create active street frontages and See Land Use Chapter Goal LU-G-3. Community introduce pedestrian -scaled street networks and street designs. Development LU-P-18 Land Use Development should be sensitive to the building form, density, See Land Use Chapter Goal LU-G-3. Community massing, and scale of surrounding residential neighborhoods. Development Policies — Town Center Mixed Use Ensure that any reuse, redevelopment, or refurbishment of the Town Center area maintains a dominance of retail, dining, and entertainment uses. Allow residential uses within the designation's Community LU-P-35 Land Use permitted maximum range, as well as offices, either on upper floors See Land Use Chapter Goal LU-G-4. Development or otherwise in locations that do not detract from the area's predominant role as a community shopping, dining, and entertainment destination. Prioritize and support renovation, infill, and reuse of the existing commercial center. Require, where appropriate, redesign and LU-P-36 Land Use modernization of architectural treatment and the introduction of See Land Use Chapter Goal LU-G-4. Community finer -grained pedestrian network, as well as utilization of parking Development lots to create central gathering spaces and make the Town Center more pedestrian -friendly. Page 7 of 50 Page 23 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Utilize buildings and streetscapes to define the public realm and encourage pedestrian activity and comfort. To further promote Community LU-P-37 Land Use these objectives, incorporate attractive landscaping elements and See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Development usable outdoor green spaces, and discourage new drive through uses. Promote site designs that create an active street frontage and Community LU-P-38 Land Use screen off-street parking from the Diamond Bar Boulevard and See Land Use Chapter Goal LU-G-4. Development Golden Springs Drive frontages. Streetscape and intersection improvements along the major corridors of South Diamond Bar Boulevard and Golden Springs Community LU-P-39 Land Use Drive should enhance connectivity, comfort, and safety for all See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Development modes of travel, and increase accessibility to and from surrounding areas. Study, as necessary, the implementation of safe pedestrian connectivity between the north and south sections of the Town See Community Character & Placemaking Chapter Policy CC-G-5 Center Mixed -Use project site and at Lorbeer Middle School. for the update on the Diamond Bar Boulevard Complete Streets LU-P-40 Land Use Potential strategies for achieving safe pedestrian connectivity may Corridor Project, which includes pedestrian safety enhancements at Public Works include traffic calming measures along the roadways, crosswalk the intersection of Diamond Bar Boulevard and Golden Springs visibility improvements, ensuring adequate time for walk signals, Drive. refuge islands, bulb -outs, bridges, and others. Maximize accessibility for transit, automobiles, cyclists, and Community LU-P-41 Land Use pedestrians to the Town Center from surrounding neighborhoods, See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Development the Metrolink station, and other Diamond Bar destinations. Avoid expanses of surface parking and encourage the Community LU-P-42 Land Use consolidation and location of parking to the rear or side of buildings See Land Use Chapter Goal LU-G-4. Development where appropriate. When updating the Development Code's parking standards or preparing specific plans, evaluate parking ratios for the Town Center to balance the financial feasibility of development projects Community LU-P-43 Land Use with the provision of adequate parking for visitors. Coordinate with See Land Use Chapter Goal LU-G-4. Development developers and transit agencies to the extent possible to provide alternative modes of transportation to allow for reduced parking requirements. Policies — Community Core Overlay Provide streetscape and intersection improvements along Golden Intersection Safety Improvements on Golden Springs Drive at LU-P-51 Land Use Springs Drive to enhance comfort and safety for all modes of travel Golden Prados Drive Public Works and increase accessibility to and from surrounding areas. Page 8 of 50 Page 24 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT In August 2025, the City Council approved the installation of "No Right Turn on Red" and "Yield to Pedestrian" signage at the intersection of Golden Springs Drive and Golden Prados Drive. These improvements encourage safer driving habits and enhance pedestrian safety. See Community Character & Placemaking Chapter Policy CC-G-5 for the update on the Diamond Bar Boulevard Complete Streets Corridor Project. PUBLIC FACILITIES, OPEN SPACE, AND HILLSIDES Policies Ensure that development on privately owned, residentially designated land in hillside areas is compatible with surrounding natural areas promoting the following design principles: a) Minimize —as articulated by the landform grading criteria of the Development Code's Hillside Management regulations —excavation, grading, and earthwork to retain natural vegetation and topography; b) Preserve existing vistas of significant hillside features such All new residential development requires review and approval by the as ridgelines, particularly from public places; Planning Commission through a Development Review application Community c) Do not create unsafe conditions; process to ensure compliance with the design principles listed. Development d) Incorporate site and architectural designs that are sensitive LU-P-56 Land Use to natural contours and land forms and hydrological MS4 Permit and NPDES Program Compliance features; To comply with the City's MS4 Permit and Municipal NPDES public Works e) Preserve natural watersheds, including existing vegetation Program, the City conducted investigations for illicit discharges and within undeveloped hillside areas to the maximum extent inspected eligible businesses for stormwater-related violations. feasible, including mature trees and native plant materials; f) Incorporate fuel modification as part of the Fire Department's approved fuel modification program; g) Utilize planting palettes consisting of drought tolerant, fire resistant, non-invasive plants that are native to or compatible with those in the surrounding area; and h) Group plants within swale areas to more closely reflect natural conditions within landform graded slopes. ECONOMIC DEVELOPMENT Goals ED-G-1 Economic Development Prioritize infill development opportunities and the reuse of existing See Land Use Chapter Goal LU-G-4. Community vacant commercial space to grow the city s base of residents and Development Page 9 of 50 Page 25 of 328 POLICY # CHAPTER GOALS & POLICIES ]STATUS DEPARTMENT employment to ensure long-term fiscal sustainability and promote conservation of natural open space. Provide for the development of jobs and commercial uses within The TCSP envisions the Town Center to become Diamond Bar's ED-G-2 Economic Development Diamond Bar to reduce residents' commutes, and to encourage downtown, a mixed -use village setting where the local workforce can Community residents to shop and dine locally. live and work, and provide the greater community with more local Development options to shop and dine. ED-G-3 Economic Development Support the retention, rehabilitation, and/or expansion of existing See Land Use Goal LU-G-11. Community businesses, and the attraction of new businesses. Development Policies — Commercial Centers Create commercial centers or districts that have a sense of place and provide attractive places to shop, dine, and gather. Within Community ED-P-3 Economic Development these areas, support the development of uses and distinct See Land Use Chapter Goal LU-G-4. Development characters that complement other commercial areas within Diamond Bar and adjacent jurisdictions. Policies — Community -Serving Uses Home based businesses are allowed, and are required to comply with the operating standards in Diamond Bar City Code Section 22.42.070, where the business shall be incidental and secondary to Allow for home occupations where compatible with the privacy and the residential use of the property. Modifications that alter the Community ED-P-7 Economic Development residential character of the neighborhood. character of the residence or change its occupancy classification are Development prohibited, and activities that create nuisances, such as glare, light, noise, solid waste, or other characteristics in excess of that customarily associated with similar residential uses are prohibited. 95 home -based business licenses were issued in 2025. 2. Community Character & Placemaking Page 10 of 50 Page 26 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT CC-G-2 CC-G-4 CC-G-5 CC-G-6 Community Character & Placemaking Community Character & Placemaking Community Character & Placemaking Community Character & Placemaking Policies — City Identity CC-P-2 CC-P-5 Community Character & Placemaking Community Character & Placemaking Encourage development within mixed -use areas that is inviting to pedestrians, promotes community interaction and activity, and contributes to an engaging street environment. Preserve the scale and character of existing residential neighborhoods and ensure sensitive transitions between densities and uses. Provide an expanded pedestrian and bicycle infrastructure network to improve connectivity throughout the city where topography and technology permit. Encourage high -quality, human -scaled design and development that respects the surrounding built environment while offering a diversity of building types. Incorporate prominent corner architectural features, such as prominent entries or corner towers, on new development at key intersections or gateways. Establish a landscaping palette made up of native, drought -tolerant plants and stormwater management systems with a view to enhancing beautification and sustainable landscaping practices. See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Community Development See Land Use Chapter Goal LU-G-3, Policies LU-P-1 and LU-P-8. Community Development Diamond Bar Boulevard Complete Streets Corridor In November 2025, the City Council awarded a $8.8M construction contract award for the Diamond Bar Boulevard Complete Streets Project. The City secured adequate grant funding for the costs of the construction phase. A pre -construction meeting with the contractor was held in December 2025, and work is planned to start in February 2026. The project is planned for completion in February 2027. See Land Use Chapter Goal LU-G-3. See Community Character & Placemaking Chapter Goal CC-G-S for update on the Diamond Bar Boulevard Complete Streets Project. See Land Use & Economic Development Chapter Policy LU-P-5 and Community Character & Placemaking Chapter Goal CC-G-5 and Policy CC-P-1. The streetscape design in the TCSP project area will be centered around reducing the number of years to carbon neutral/zero carbon in order to reduce the effects of climate change by planting evergreen trees and installation of cool pavements such as hydro pavers. As part of the FY2025-26 Capital Improvement Program, the City Council approved the development of landscaping and irrigation standards for Landscape Assessment District Nos. 39-2022 and 41- 2021. The awarded consultant will evaluate the existing conditions and recommend standardized improvements for district -maintained areas. The improvements include the removal of nonfunctional turf areas, and prioritize the use of drought -tolerant plants and water efficient irrigation systems. Public Works Community Development Public Works Community Development Public Works Page 11 of 50 Page 27 of 328 POLICY # CHAPTER GOALS & POLICIES Prioritize sustainability in site design. When incorporating on -site Community Character & stormwater management through the use of bioswales, rain CC-P-6 Placemaking gardens, permeable pavement, and/or other available low -impact development technologies, require such features to be aesthetically integrated into the site design. Policies — Streetscapes & Building to Street Interface CC-P-9 CC-P-11 CC-P-12 Community Character & Placemaking Community Character & Placemaking Community Character & Placemaking Encourage pedestrian orientation in mixed -use development using a variety of site planning and architectural strategies, such as locating and orienting buildings to street frontages, plazas, or pedestrian paseos; providing visual transparency through fenestration; entries and arcades close to the street edge and sidewalk; and/or incorporating porches, patios, or outdoor spaces that overlook or interact with front yards or sidewalks. In residential and mixed -use areas, use traffic calming measures such as pavers, bollards, sidewalk bulb -outs, and speed humps to slow travel speeds. Develop and enforce private slope maintenance standards for properties with rear descending slopes that face public streets, with special emphasis on those along Grand Avenue, Diamond Bar Boulevard, Golden Springs Drive, Pathfinder Road, and the freeways. STATUS The City requires developers to responsibly manage and mitigate the stormwater quality impacts from their projects, in compliance with the City's MS4 Permit and NPDES Program. Every project's proposed Low Impact Development (LID) best management practices are reviewed and approved by the City. The TSCP is intended to create vibrant public realm with a high intensity mix of uses to include retail, office, hotel, civic, and residential uses, and a bustling active environment during both day and evening hours. Numerous new public spaces, both hardscape squares and landscaped greener park spaces, will be located throughout the Plan area to provide a variety of environments that will serve residents and downtown visitors alike. See Land Use Chapter Goal LU-G-4 and LU-P-7 and Community Character & Placemaking Chapter Goal CC-G-5 and Policy CC-P-I Neighborhood Traffic Management Program In August 2025, the City Council approved the installation of 3 new stop signs along Hawkwood Road, at the intersections of Chirping Sparrow Road, Ambushers Street, and Barbi Lane. The implemented stop signs help establish right-of-way and support safe traffic flow throughout the neighborhood. Private Slopes Affected by the February 2024 Winter Storms Through 2025, the City worked with private property owners to restore the private slopes affected by the February 2024 Winter Storms. A Grading Permit was issued in July 2025 for the property owner to rehabilitate the private slope along Diamond Bar Boulevard. The City continues to work with other affected property owners on restoring the private slopes along Golden Springs Drive. DEPARTMENT Public Works Community Development Public Works Public Works Policies — Parks & Open Spaces CC-P-13 Community Character & Encourage landscaped common public spaces to be incorporated See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Community Placemaking into new mixed -use development. Development Ensure that common spaces be integrated elements of Community Character & Community CC-P-16 Placemaking development, coordinating landscaping and amenities with the See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Development projects architecture and character. Policies — Site Planning & Parking Page 12 of 50 Page 28 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT See Land Use Chapter Goal LU-G-4. Encourage the aggregation of individual small lots into larger CC-P-17 Community Character & development parcels within mixed -use areas that will support an The TCSP is an important component of the City's overall strategy Community Placemaking appropriately -scaled, cohesive and economically viable to revitalize older areas and expand housing production. Incentives Development development. for lot consolidation are being considered as the TCSP is being crafted to encourage the improvement of underutilized properties. As large vacant or underutilized sites are developed or redeveloped, maximize multimodal accessibility with fine-grained Community Character & street networks and walkable block sizes. Generally limit new block Community CC-P-18 Placemaking sizes to a maximum of about 400 feet in length. Mid -block plazas or See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. Development alleys may be considered if the intent is to ensure fine-grained patterns where pedestrian access can be accommodated in intervals no more than 400 feet apart. See Land Use Chapter Goal LU-G-4 and Policy LU-P-7. The planning goals for the TCSP include the following: 1. To implement the community vision, goals and policies of the General Plan, which established the Town Center Mixed -Use land use designation to "foster the development of a vibrant, pedestrian -oriented Town Center in Diamond Bar that serves as a place for Diamond Bar's residents to shop, dine, and gather. Site plans should be designed to create pedestrian -oriented neighborhoods that follow these guidelines: 2. To make the town center a complete neighborhood with a a) Buildings should be oriented to the street; sense of place, that takes advantage of its location, to provide b) Garages and parking areas should be screened and/or residents and visitors a unique experience. CC-P-21 Community Character & Placemaking located at the side or rear of properties wherever possible; P p p 3. Ensure that the physical design and programming of the town Community Development and center supports health, wellbeing, and environmental c) Landscaping, sidewalk conditions, and other streetscape sustainability, the latter so as to make progress toward elements should be improved during rehabilitation and new meeting the greenhouse gas reduction targets of the construction. Diamond Bar Climate Action Plan by supporting compact, infill, mixed -use development. 4. The town center allows for car-lite/car-optional living allowing those who choose not to use their car on a daily basis or who choose not to own a car at all to be easily accommodated thus furthering progress to the City's climate action goals. 5. The town center provides great public spaces, and small parks with regenerative landscapes to support the goal of environmental sustainability. Page 13 of 50 Page 29 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT CC-P-22 Community Character & Orient buildings adjacent to public spaces such that entries, See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking windows, and seating areas face the public space. P-21. Development Where appropriate and feasible, locate and orient active uses (such CC-P-23 Community Character & as commercial uses and parks) along the street edges of new See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking mixed -use development, at street corners, or along main roadways P-21. Development internal to larger developments. CC-P-25 Community Character & Encourage the design of shared parking for commercial and office See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking uses where possible. P-21. Development CC-P-26 Community Character & Placemaking Policies — Building Massing and Design CC-P-30 CC-P-32 CC-P-33 Community Character & Placemaking Community Character & Placemaking Community Character & Placemaking Establish reduced minimum commercial parking requirements for all development within new mixed -use land use designations. Reduced parking requirements should be supported by proximity to transit, shared parking, and technologies that, once mainstreamed, would reduce the need for conventional parking layouts. Ensure that infill residential development is designed to be sensitive to the scale, character, and identity of adjacent existing development. Emphasize human -scaled design within large-scale commercial and mixed -use centers. Employ measures such as articulated massing, awnings, and landscape elements to break down the scale of development. Encourage new mixed -use and commercial development to incorporate visual quality and interest in architectural design on all visible sides of buildings through the following approaches: a) Utilizing varied massing and roof types, floor plans, detailed planting design, or color and materials; See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Community Development All new residential development requires review and approval by the Planning Commission through a Development Review application process to assess a project's compatibility, architectural design, size, scale and massing with the neighborhood. The Planning Commission reviews the design to ensure compliance with the City's General Plan policies and design guidelines, and ensure sensitive transitions between densities and uses. On August 5, 2025, the City received an application for the demolition of an existing office building and associated improvements to allow for the development of a for -sale residential community consisting of 49 attached and detached condominium units. The project site is being reviewed to ensure sensitive transitions to adjacent uses, particularly the nearby residential neighborhoods. Community Development See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community P-21. Development See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community P-21. Development Page 14 of 50 Page 30 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT b) Maintaining overall harmony while providing smaller -scale variety; and c) Articulating building facades with distinctive architectural features like awnings, windows, doors, and other such elements. Community Character & Update the City of Diamond Bar Citywide Design Guidelines as Community CC-P-34 Placemaking needed to reflect the design guidance articulated in the General See Land Use Chapter Goal LU-G-3. Development Plan. TOWN CENTER MIXED USE FOCUS AREA 10 Goals CC-G-11 Community Character & Support an intense mix of active uses on both sides of Diamond Bar See Land Use Chapter Goal LU-G-4 and Policy LU-P-21. Community Placemaking Boulevard within the Town Center focus area. Development CC-G-12 Community Character & Establish an inviting and comfortable public realm that encourages See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking pedestrian activity in the Town Center focus area. P-21. Development CC-G-13 Community Character & Establish a new pedestrian -oriented "Main Street" within the Town See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking Center focus area lined with retail uses. P-21. Development Policies Through development review, ensure that the Town Center remains CC-P-41 Community Character & predominantly a community shopping, dining, and entertainment See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Community Placemaking destination, and that residential uses and offices are located so as Development not to detract from this image. CC-P-42 Community Character & Prioritize retail and other uses that promote pedestrian activity on See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking the ground floor of buildings. P-21. Development Establish gateways to the Town Center area at the intersections of CC-P-43 Community Character & Diamond Bar Boulevard and Golden Springs Drive and at Diamond See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking Bar Boulevard and Palomino Drive. Gateway elements should be P-21. Development consistent with the gateway design palette. As the Town Center redevelops, enhance pedestrian connectivity CC-P-44 Community Character & throughout the district through the incorporation of a new "Main See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking Street" within the western portion of the focus area that is off of or P-21. Development set back from Diamond Bar Boulevard. The design of new development should be pedestrian -oriented, with CC-P-45 Community Character & the majority of building frontages located at the new street edge and See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking with entrances located along the roadway or along pedestrian P-21. Development pathways or public spaces. Page 15 of 50 Page 31 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Community Character & Ensure that new buildings employ horizontal and vertical building Community CC-P-46 Placemaking articulation and diversity in color, materials, scale, texture, and See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Development building volumes. Community Character & Develop specific building height and other development standards Community CC-P-47 Placemaking through implementation mechanisms such as the City's Zoning See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Development Ordinance or a master or specific planning process. CC-P-48 Community Character & Encourage dining establishments to incorporate outdoor dining or See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Community Placemaking sidewalk cafes. Development Encourage reductions in surface parking and allow for the CC-P-49 Community Character & development of consolidated parking structures, provided that they See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking are screened from view from Diamond Bar Boulevard and Golden P-21. Development Springs Drive. Where possible, above -grade parking structures should be Community Character & wrapped with pedestrian uses where they front onto active streets. See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community CC-P-50 Placemaking If active uses are not feasible, frontages should be architecturally P-21. Development attractive. This may include unique designs and materials such as glass, articulated masonry, murals, or landscaping setbacks. Enhance the pedestrian experience along Diamond Bar Boulevard CC-P-51 Community Character & within the Town Center area with widened sidewalks, shade trees, See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community Placemaking and pedestrian amenities such as street furniture, attractive paving, P-21. Development pedestrian -scaled lighting, and landscape buffers. 3. Circulation POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT CIRCULATION 1W This Chapter is aimed at improving the transportation network within the City, balancing the circulation needs with safety and access across a variety of modes of transportation, including automobile travel, public transit, non -motorized transportation and goods movement through a Complete Streets approach. TRANSPORTATION NETWOR111111111 K AND STREET DESIGN Goals Improve the operating efficiency of the transportation system by Transportation Study Guidelines reducing vehicle travel demand and providing opportunities for CR-G-1 Circulation other modes of travel. Before approving roadway improvements The City's Transportation Study Guidelines are implemented in the Public Works that focus on increasing vehicle capacity, consider alternatives that review of the new development projects for, among other things, the reduce vehicle volumes and prioritize projects that would reduce mitigation and reduction of the level of Vehicle Mile Traveled (VMT) single -occupancy vehicle use and greenhouse gas emissions. of the projects. Additionally, the City updated the Transportation Page 16 of 50 Page 32 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Study Guidelines per the new requirements and clarifications from the State and the new (2020) model data from SCAG. Maintain a street classification system that considers the broad role of streets as corridors for movement but also reflects a Complete Streets concept that enables safe, comfortable, and attractive See Community Character & Placemaking Chapter Goal CC-G-5 for CR-G-2 Circulation access for pedestrians, bicyclists, motorists, and transit users of all update on the Diamond Bar Boulevard Complete Streets Project. Public Works ages and abilities, in a form that is compatible with and complementary to adjacent land uses, including neighborhood schools. Strive to achieve a finer grained network of streets and CR-G-3 Circulation pedestrian/bicycle connections as development occurs, especially See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community in focus areas such as the Transit -Oriented, Neighborhood, Town P-21. Development Center, and Community Core mixed -use areas. Design roadways serving pedestrian -oriented mixed -use areas to See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community CR-G-4 Circulation promote neighborhood interaction, pedestrian comfort and P-21. Development walkability, and commercial patronage. Develop neighborhood streets and alleys that encourage walking, CR-G-5 Circulation biking, and outdoor activity through engineering and urban design See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community principles that reduce the potential for speeding and cut -through P-21. Development traffic, which may include traffic calming measures. Policies When redesigning streets, plan for the needs of different modes by incorporating elements such as shade for pedestrians, safe See Community Character & Placemaking Chapter Goal CC-G-5 for CR-P-1 Circulation pedestrian -friendly crossings/ intersections, lighting at the update on the Diamond Bar Boulevard Complete Streets Project. Public Works pedestrian scale, bike lanes, signage visible to relevant modes, transit amenities, etc. Plan for and provide new connections within the Transit -Oriented, Neighborhood, Town Center, and Community Core mixed -use areas to create finer grained, pedestrian -scaled circulation See Community Character & Placemaking Chapter Goal CC-G-5 for CR-P-3 Circulation networks that support the development of connected and update on the Diamond Bar Boulevard Complete Streets Project. Public Works accessible neighborhoods. Connections should facilitate the use of alternatives to single -occupancy vehicles, such as walking, See Circulation Chapter Policy CR-P-1. bicycling, and transit by improving the safety and accessibility of those modes. Develop traffic calming strategies for Diamond Bar Boulevard See Community Character & Placemaking Chapter Goal CC-G-5 for CR-P-4 Circulation between Temple Avenue and Golden Springs Drive in order to update on the Diamond Bar Boulevard Complete Streets Project. Public Works provide a safe and comfortable pedestrian -friendly environment Page 17 of 50 Page 33 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT C R-P-5 Circulation VEHICLE CIRCULATION Goals CR-G-7 CR-G-8 Circulation Circulation along and through the Neighborhood Mixed Use and Town Center Mixed Use areas. Necessary transportation improvements should be in place, or otherwise guaranteed to be installed in a timely manner, before or concurrent with new development. In evaluating whether a transportation improvement is necessary, consider alternatives to the improvement consistent with CR-G-1, and the extent to which the improvement will offset the traffic impacts generated by proposed and expected development. Ensure smooth traffic flows by maintaining or improving traffic levels of service (LOS) that balance operational efficiency, technological and economic feasibility, and safety. Encourage reduction in vehicle miles traveled (VMT) as part of a strategy to reduce greenhouse gas (GHG) emissions. See Circulation Chapter Goal CR-G-1. See Circulation Chapter Goal CR-G-1. See Circulation Chapter Goal CR-G-1. Public Works Public Works Public Works CR-G-10 Circulation Discourage traffic from SR-57 and SR-60 from using Diamond Bar See Land Use & Economic Development Chapter Policy LU-P-14 for Public Works roadways as alternatives to the freeway. update on the SR57160 Confluence Project. Policies — Level of Service (LOS) Standards Balance meeting LOS standards with the need to reduce VMT CR-P-12 Circulation through maintaining and supporting multi -modal connectivity such See Circulation Chapter Goal CR-G-1. Public Works as transit, bicycling, walking, and by encouraging infill development with a pedestrian -friendly urban design character. to] :aaK3 [el:a'aEl Circulation Circulation Maintain a standard of LOS D during peak hour conditions on all streets in the City's jurisdiction, with exceptions as noted below: a) Brea Canyon Rd south of Diamond Bar Blvd (LOS F) b) Brea Canyon Rd north of Diamond Bar Blvd (LOS E) c) Grand Ave west of Country View Dr (LOS E) d) Diamond Bar Blvd at SR-60 Eastbound Ramps (LOS F). Prioritize pedestrian movement and safety— through wider sidewalks, more frequent pedestrian crossings, sidewalk bulbouts, median pedestrian refuges etc. —rather than LOS in Community Character Priority Areas, which are areas designated for higher density mixed -use development in the General Plan. See Section 4.4 for more detailed policies on bicycle and pedestrian movement in mixed -use areas. See Circulation Chapter Goal CR-G-1. See Community Character & Placemaking Chapter Policy CC-G-S for the update on the Diamond Bar Boulevard Complete Streets Corridor Project. See Land Use & Economic Development Chapter Policy LU-P-61 for the update on the Intersection Safety Improvements on Golden Springs Drive at Golden Prados Drive. Public Works 1117MUMOMW Page 18 of 50 Page 34 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Maintain roadway design standards to manage vehicle speeds and See Community Character & Placemaking Chapter Policy CC-G-5 CR-P-17 Circulation traffic volumes, updating them as needed. for the update on the Diamond Bar Boulevard Complete Streets Public Works Corridor Project. Policies — Adaptive Traffic Control (ATCS) & Intelligent Traffic Systems (ITS) Triennial Pavement Management Program Update In February 2025, the City Council awarded a consulting services agreement for the Pavement Management Program (PMP) update. Implement measures such as additional signal timing and Each City street is assessed by the consultant and assigned a synchronization, speed limit regulations, and ITS techniques to Pavement Condition Index (PCI) score. The assigned PCI score CR-P-20 Circulation increase safety and reduce congestion. Maintain a pavement determines the level of treatment required for pavement Public Works management system and maintenance program for all public maintenance. The City utilizes the completed PMP to plan future roadways throughout the City. residential and arterial pavement rehabilitation projects. The PMP report was finalized in August 2025, and the average Citywide PCI score (for arterial and residential streets) was 78. See Land Use & Economic Development Chapter Policy LU-P-14. On an ongoing basis, examine opportunities to avoid delay, spillover, or cut -through traffic onto Diamond Bar's roadways through techniques such as adaptive traffic control systems along CR-P-21 Circulation major corridors and traffic calming measures along cut -through See Land Use & Economic Development Chapter Policy LU-P-14 Public Works routes that would reduce speeds and discourage drivers from and Circulation Chapter Policy CR-P-20. electing to drive on them. Consider financial and technological feasibility and community priorities to determine whether and how strategies should be implemented. Policies — Safety Implement traffic calming measures to slow traffic on local and CR-P-22 Circulation collector residential streets and prioritize these measures over See Community Character & Placemaking Chapter Policy CC-P-11. Public Works congestion management where appropriate and feasible. Maintain the integrity of existing residential areas and discourage cut -through traffic by retaining cul-de-sacs and implementing other CR-P-23 Circulation traffic calming measures that promote safe driving at speeds See Community Character &Placemaking Chapter Policy CC-P-11. Public Works appropriate to the surrounding neighborhood, particularly at Prospectors Road, Chaparral Drive, Sunset Crossing Road, Lycoming Street, and Washington Street. Policies — Inter -Jurisdictional Coordination CR-P-26 Circulation As opportunities arise, coordinate with other jurisdictions, including See Circulation Chapter Policy CR-P-2. Public Works neighboring cities, Los Angeles County, San Bernardino County, Page 19 of 50 Page 35 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT and Caltrans, on improvements to street segments common to the City of Diamond Bar and other jurisdictions. Encourage improvements to regional routes and arterial streets to CR-P-27 Circulation account for environmental, aesthetic, and noise concerns, as well See Community Character & Placemaking Chapter Policy CC-P-1. Public Works as to provide adequate buffers to adjacent land uses. CR-P-29 Circulation Solicit State and Federal funds to improve area freeways and local See Community Character & Placemaking Chapter Goal CC-G-S. Public Works streets. PEDESTRIAN AND BICYCLE CIRCULATION Goals CR-G-11 Circulation Expand and strengthen existing pedestrian and cyclist network and See Community Character & Placemaking Chapter Goal CC-G-S. Public Works facilities. CR-G-12 Circulation Improve safety and accessibility for pedestrians and cyclists. See Community Character & Placemaking Chapter Goal CC-G-S. Public Works Policies — Bicycle & Pedestrian Movement in Mixed Use Areas Ensure a safe environment for pedestrians and cyclists while allowing for local traffic to access freeways in the Neighborhood Mixed Use area through the following strategies: a) Widening sidewalks, providing planting strips between sidewalks and streets and providing pedestrian amenities such as shade trees and street furniture along Diamond Bar Boulevard; See Community Character & Placemaking Chapter Goal CC-G-S. All b) Implementing traffic calming measures such as reduced of these elements and considerations are being incorporated into the CR-P-39 Circulation vehicle speeds, striping and signage along Diamond Bar design of the Diamond Bar Boulevard Complete Street Project and Public Works Boulevard; the future TCSP. After completion, this project will be referenced as c) Buffering bike lanes along Diamond Bar Boulevard; the Complete Streets template for the remainder of the City. d) Enhancing pedestrian crossings at the intersection of Diamond Bar Boulevard and Sunset Crossing Road, at Diamond Bar Boulevard and Highland Valley Road, and at Diamond Bar Boulevard and the SR-60 on/off ramps; and e) Incorporating multi -use pathways internal to new development and connecting to existing development. Provide for a vibrant Town Center that encourages pedestrian activity and comfort within the Town Center Mixed Use area while accommodating through traffic along Diamond Bar Boulevard See Land Use Chapter Goal LU-G-4 and Policies LU-P-7 and CC- Community CR-P-40 Circulation through the following strategies: P-21. Development a) Establishing a new pedestrian -oriented main street or pedestrian pathway in the Town Center; See Circulation Chapter Goal CR-P-39. Public Works b) Enhancing the pedestrian experience along Diamond Bar Boulevard within the Town Center area with widened Page 20 of 50 Page 36 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT sidewalks, shade trees, and pedestrian amenities such as street furniture, attractive paving, pedestrian -scaled lighting, and landscape buffers; c) Buffering bike lanes along Diamond Bar Boulevard; d) Improving crosswalks at the intersection of Diamond Bar Boulevard and Palomino Drive, at Diamond Bar Boulevard and Golden Springs Drive, and where Diamond Bar Boulevard intersects with the driveway to the Town Center; and e) Strengthening cyclist and pedestrian connections between the Town Center area and nearby schools to provide safe and convenient routes to the Town Center for students by identifying barriers such as safety hazards and gaps in the bicycle and pedestrian networks and implementing improvements to address those barriers. Policies — Safety Enhance bicycle and pedestrian safety and comfort where feasible through means such as: a) Introducing bicycle- and pedestrian -level street lighting to improve safety at night; b) Furnishing intersections with crosswalks on all legs of the intersection; c) Improving pedestrian safety with intersection design features such as improved signal timing, sidewalk bulbouts, See Community Character & Placemaking Chapter Goal CC-G-5. All pedestrian refuge islands with "noses" that extend past the of these elements and considerations are being incorporated into the CR-P-44 Circulation crosswalks, advance vehicle stop bars, high visibility design of the Diamond Bar Boulevard Complete Street Project and Public Works crosswalk striping or decorative paving; the future TCSP. After completion, this project will be referenced as d) Improving bicycle safety with intersection design features the Complete Streets template for the remainder of the City. such as bicycle detection and signalization, painted bike boxes, and intersection crossing markings; e) Widening sidewalks, providing planting strips between sidewalks and streets and providing pedestrian amenities such as shade trees and street furniture; and f) Implementing traffic calming measures to reduce vehicle speeds and congestion. Routinely review pedestrian and cyclist collision data for type, The City always reviews collision data to develop prevention CR-P-45 Circulation location, severity, and cause, and develop strategies to prevent strategies. This process occurs after the Los Angeles County Public Works these collisions. Sheriffs Department concludes its investigation of the collision and provides the accident report with findings. Page 21 of 50 Page 37 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT PUBLIC TRANSPORTATION Goals CR-G-13 Policies C R-P-48 PARKING Goals CR-G-14 Policies CR-P-53 C R-P-54 Circulation Circulation Circulation Circulation Circulation Policies — Truck Routes CR-P-64 CR-P-65 Circulation Circulation Support the availability, efficiency, and effectiveness of public transit service. As opportunities arise, work with Foothill Transit to maintain and improve bus stops and shelters, as well as identify areas where service can be improved or expanded to increase system use. Provide adequate parking for all land use types, while balancing this against the need to promote walkable, mixed -use districts and neighborhoods in targeted areas, and promoting ride -sharing and alternative transportation modes. Update parking standards in the Development Code to ensure that they are reflective of the community's needs, using current data on parking demand and taking into consideration demographics and access to alternative modes of transportation. Incorporate criteria in the Development Code to allow reductions in parking requirements in exchange for VMT reduction measures. Continue prohibiting trucks heavier than 5 tons from operating on designated residential streets, except for emergency, maintenance, residential moving trucks, and transit vehicles, to maintain pavement integrity. Periodically review collision data for type, location, severity, and cause. Develop countermeasures for sites with recurrent truck - involved collisions. See Circulation Chapter Policy CR-P-1 The City maintains and improves bus stops and shelters as necessary, and coordinates with Foothill Transit to identify areas where service can be improved or expanded to increase system use. See Land Use Chapter Goal LU-G-4. Public Works Public Works Community Development The City is currently implementing during project reviews. I Public Works The City is currently implementing during project reviews. I Public Works The City currently implements this restriction. The City reviews collision data to develop prevention strategies. This process occurs after the Los Angeles County Sheriff's Department concludes its investigation of the collision and provides the accident report with findings. Public Works Public Works Page 22 of 50 Page 38 of 328 4. Resource Conservation POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT RESOURCE CONSERVATION A conservation element is required to provide guidance for the conservation, development, and utilization of natural resources, including water quality and hydraulic force, forests, soils, rivers and other waters, harbors, fisheries, wildlife, minerals, and others as applicable to each jurisdiction. An open space element is intended to ensure that cities and counties recognize that open space land is a limited and valuable resource, and that they prepare and carry out open space plans to guide the comprehensive long-range preservation and conservation of open space land. The Resource Conservation Chapter provides policies to guide the City's stewardship of its resources, ensuring the conservation and enhancement of open spaces, biological resources, water and air quality, and cultural resources. OPEN SPACE Goals The Canyon Loop Trail project included many improvements to the existing trail and triggered habitat monitoring to comply with all state and federal requirements for the protection, replacement and Preserve to the extent possible open space ridgelines, hilltops, and restoration of native habitat affected by the project. The City RC-G-3 Resource Conservation prominent slopes for aesthetic, biological and natural resource contracted with Michael Baker International and Helix Environmental Parks & Recreation conservation, and safety purposes. to implement the five-year Habitat Mitigation Monitoring Program to implement mitigation measures supporting the natural habitat found around the Canyon Loop Trail. Currently, three unique areas on the trail are being restored and enhanced to meet the existing conditions. Policies Minimize visual and environmental impacts to ridgelines, hilltops, and slopes through regulations that minimize grading, ensure that The Planning Division reviews each project to ensure compliance development conforms to natural topography, and maximize safety, with the City's General Plan policies and City's Hillside Management Community RC-P-7 Resource Conservation correlating development intensity with the steepness of terrain. Design Guidelines. The guidelines were created to ensure that Development Landform grading criteria and maximum allowable densities shall development will complement the character and topography of be based upon the slope density formula as set forth in the hillside areas set forth in the Development Code. Development Code. To the extent feasible, support and cooperate with the efforts of other jurisdictions and conservation organizations to protect In coordination with the cities of Chino Hills and Industry, a one day prominent ridges, slopes, and hilltops in and adjacent to the City guided tour of the Tres Hermanos property was provided free of RC-P-8 Resource Conservation and its Sphere of Influence. charge for approximately 100 members of the public on September Parks & Recreation Such features include, but are not limited to, areas identified 27, 2025. The guided tours included exhibits and historical by Los Angeles County as Significant Ecological Areas; presentations led by local historians, current City Managers and Tonner Canyon; the hills within Tres Hermanos Ranch; and staff. the hillsides along SR-57, between Diamond Bar and Brea. Page 23 of 50 Page 39 of 328 BIOLOGICAL RESOURCES Goals RC-G-6 Policies RC-P-9 RC-P-10 Resource Conservation Resource Conservation Resource Conservation WATER RESOURCES Goals RC-G-7 I Resource Conservation Utilize native and drought -tolerant vegetation in landscaping, site stabilization and restoration where practical to prevent the spread of invasive plant species into natural open spaces. Require, as part of the environmental review process prior to approval of discretionary development projects involving parcels within, adjacent to, or surrounding a significant biological resource area, a biotic resources evaluation of the site by a qualified biologist. Focused plant surveys shall be conducted at the appropriate time of year, and local reference populations checked to ensure detectability of the target species. Wildlife shall also be evaluated by a qualified biologist through appropriate survey or trapping techniques necessary to determine presence. Such evaluation shall analyze the existing and potential natural resources of a given site as well as the potential for significant adverse impacts on biological resources. The report shall identify measures to avoid, minimize, or mitigate any impacts to species that have been observed or have the potential of being present on the site. In approving any permit based on the evaluation, the City shall require implementation of mitigation measures supported by the evaluation, or work with the applicant to modify the project if mitigation is determined not to be adequate to reduce the impacts to a non -significant level. Require, to the greatest extent feasible, new development to preserve mature native trees including oak and walnut, and trees of significant cultural or historical value such as sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree Preservation and Protection Ordinance. Review the ordinance periodically and update it as necessary to reflect current best practices. Protect waterways —including creeks, riverines, artesian springs, seeps, and wetlands —and watersheds in Diamond Bar from pollution and degradation as a result of urban activities. During project review, the Planning Division ensures that the plant palette is diverse, Southern California native and drought -tolerant vegetation is utilized, and that the planting and irrigation plans comply with the City's Water Efficient Landscaping Ordinance. In compliance with the Mitigation Monitoring and Reporting Program (MMRP) for the Canyon Loop Trail project, focused plant and nesting bird surveys were conducted prior to any habitat restoration work during the breeding seasons of the California Gnatcatcher and Cactus Wren. The Planning Division reviews each project to evaluate if a protected tree can be preserved or retained on -site. If preservation is not feasible, trees are required to be replanted at a minimum 3:1 ratio pursuant to the City's Tree Preservation and Protection Ordinance. Community Development Parks & Recreation Community Development See Land Use & Economic Development Chapter Policy LU-P-5. I Public Works Page 24 of 50 Page 40 of 328 Policies — Water Conservation Continually evaluate and upgrade the efficiency of City irrigation The City continues to evaluate and upgrade the efficiency of City RC-P-17 Resource Conservation systems, prioritizing the use of reclaimed water. irrigation systems and prioritize the use of reclaimed water, wherever Public Works possible and feasible. Encourage the implementation of the latest water conservation Building and Safety requires water conservation fixtures as required Community RC-P-19 Resource Conservation technologies into new developments. by the California Green Building Code (CALGreen) and the Development California Plumbing Code. Policies — Water Quality Ensure that post -development peak stormwater runoff discharge The City implements this engineering standard on all development rates do not exceed the estimated predevelopment rate and that dry projects by reviewing the stormwater quality and quantity (hydraulic RC-P-23 Resource Conservation weather runoff from new development not exceed the pre- and hydrology study) impacts and requiring construction and Public Works development baseline flow rate to receiving water bodies. maintenance of low impact development (LID) best management practices (BMPs). AIR QUALITY Goals Aim for a diverse and efficiently -operated local and regional ground See Circulation Chapter Goal CR-G-1 for VMT Guidelines and RC-G-14 Resource Conservation transportation system that reduces VMT and generates the implementation efforts. Public Works minimum amount of pollutants feasible. Policies • Building & Safety implements CALGreen. Whenever a building permit is issued for construction, CALGreen requires the building inspector to verify the reduction of dust and volatile organic compounds (VOCs). Dust control measures include watering of dirt on projects that are moving earthwork Encourage new development to minimize impacts on air quality and VOCs are limited in quantity by requiring materials with through the following measures: a. Use of building materials and certified lower VOCs be used. methods that minimize air pollution. b. Use of fuel -efficient heating • Through the implementation of the California Energy Code equipment, and other appliances, such as water heaters, swimming and CALGreen, more efficient equipment and reduced VOC's RC-P-24 Resource Conservation pool heaters, cooking equipment, refrigerators, furnaces, boiler are required respectively. The CA Energy Code requires Community units, and low or zero -emitting architectural coatings. c. Use of highly efficient heating and cooling systems through requiring Development clean air technology beyond what is required by South Coast Air high seasonal energy efficiency ratings and energy efficient Quality Management District (SCAQMD), leveraging State and local materials such as low-E (low emissivity) windows. The CA funding sources. Energy Code also requires high efficacy lighting, energy efficient switching and sensors, certified cooktop hoods, rooftop solar installations in new construction, and mostly instantaneous water heaters for new construction. CALGreen requires low emitting architectural coatings through limiting the VOC's and requiring certified listed low -emitting products including paints and sealants. Page 25 of 50 Page 41 of 328 • CALGreen requires clean air within buildings including through requiring higher minimum efficiency reporting value (MERV) filters and minimum outdoor air circulation. Higher filtration removes contaminants and outdoor air circulation reduces carbon dioxide levels within structures Conserve natural open spaces, biological resources, and Building & Safety follows various SCAQMD rules including requiring vegetation, recognizing the role of these resources in the reduction SCAQMD proof of notification before some projects are demolished,Community RC-P-25 Resource Conservation and mitigation of air pollution impacts, and the promotion of CO2 preventing wood burning fireplaces from being installed, prevention Development sequestration. of excessive dust on construction sites, and requiring SCAQMD notification prior to the issuance of permits for char -broilers. Building & Safety Department requires all construction projects to provide proper mechanical ventilation systems pursuant to the Cooperate with the ongoing efforts of the U.S. Environmental California Mechanical Code. The California Building Code limits the RC-P-28 Resource Conservation Protection Agency (EPA), SCAQMD, the Southern California amount of hazardous materials on a site which could lead to further Community Association of Governments (SCAG), and the State of California Air Toxic Air Contaminants. During construction, dust mitigation and Development Resources Board in improving air quality in the regional air basin. erosion control are required and enforced by the building inspector on any construction project. The remainder of this work is conducted through the Public Works Department. For new or modified land uses that have the potential to emit dust, odors, or TACs that would impact sensitive receptors, require the The Public Works Department requires an erosion control plan to be Community business owners to obtain all necessary SCAQMD clearances or provided prior to permit issuance, including sandbags around the Development RC-P-30 Resource Conservation permits prior to business license or building permit issuance. property and intermittent watering of a grading site. Prior to any Sensitive receptors include residences, schools, childcare demolition, the Building & Safety Division requires that SCAQMD to Public Works centers, playgrounds, parks and other recreational facilities, be notified before permits are issued. nursing homes, hospitals, and other medical care facilities. Require construction and grading plans to include State and AQMD-mandated measures to the maximum extent possible Community RC-P-33 Resource Conservation fugitive dust and pollutants generated by construction activities and Public Works implements all dust control measures during grading Development those related to vehicle and equipment cleaning, fueling and with assistance from Building & Safety during construction. maintenance as well as mono -nitrogen oxides (NOx) emissions Public Works from vehicle and equipment operations. RC-P-39 Resource Conservation Reduce paved road dust emissions through targeted street The City continuously monitors and adjusts the frequency of the Public Works sweeping of roads subject to high traffic levels and silt loadings. street sweeping service depending on the season. See Land Use & Economic Development Chapter Policy LU-P-14 for Continue to advocate at all levels of government for improvements update on the SR57160 Confluence Project. to the confluence of the SR-57 and SR-60 freeways, including the RC-P-40 Resource Conservation construction of the missing interchanges between the two freeways, The City continues to advocate for additional improvements to the Public Works to reduce congestion and delays on the freeways, as well as SR-57 and SR-60 freeways, including the missing interchanges from affected surface streets and on/offramps. the westbound SR-60 to northbound SR-57 and southbound SR-57 to eastbound SR-60. Page 26 of 50 Page 42 of 328 CULTURAL AND HISTORIC RESOURCES Policies — Tribal Cultural Resources For projects subject to AB 52, which includes the Walnut Valley Unified School District digital billboard project, the City implements resource conservation policies that require consultation with Conduct project -specific Native American consultation early in the California Native American tribes regarding potential impacts to development review process to ensure adequate data recovery and Tribal Cultural Resources. The project applicants have formally mitigation for adverse impacts to significant Native American sites. and entered into and commenced consultation with the Kizh Nation, Community RC-P-46 Resource Conservation Ensure that City staff and local developers are aware of their consultation has resulted in agreed -upon mitigation measures to Development responsibilities to facilitate Native American consultation under protect tribal cultural resources, including the presence of a qualified Senate Bill 18 and Assembly Bill 52. tribal monitor during all ground -disturbing activities. Following project approval, the applicants and the Kizh Nation will enter into a monitoring agreement, and a copy of the fully executed agreement will be provided to the City prior to issuance of any construction permits, which is anticipated to begin construction in early 2026. 5. Public Facilities and Services POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT PUBLIC FACILITIES & SERVICES This Chapter sets forth the policy framework for the City to manage infrastructure and services, identify areas for improvement, and ensure that public utilities, services, and programs can meet the needs ofthe community into - future. PARKS &RECREATION Goals Ensure that new development bears the costs of new parks and As a condition of tentative map approval, the applicant is required to PF-G-3 Public Facilities & recreation facilities that are needed to meet any increase in demand dedicate land and/or pay a fee in compliance with DBCC Section Community Services resulting from the new development, or from which the new 21.32.040 for the purpose of developing new or rehabilitating Development development would benefit. existing park or recreation facilities to serve the subdivision. Policies — General Monitor and seek to actively engage in Cal Poly Pomona's plans for City staff continue to utilize the revised Joint Use Agreement with PF-P-6 Public Facilities & the redevelopment of the former Lanterman site, and seek joint use Walnut Valley Unified School District for indoor athletic space for Parks &Recreation Services opportunities for parks and recreation facilities developed on the community programming. site. Policies — Parks & Recreation Facilities Public Facilities & Develop and maintain a parkland dedication requirement/in-lieu fee Community PF-P-8 Services consistent with the General Plan standard of five acres per 1,000 See Public Facilities and Services Chapter Goal PF-G-3. Development residents in Diamond Bar. Page 27 of 50 Page 43 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT 1»'ai [1 PF-P-17 Public Facilities Services Public Facilities Services Public Facilities Services SCHOOLS AND COMMUNITY FACILITIES Goals PF-G-4 Policies — Schools PF-P-28 UTILITIES Public Facilities Services Public Facilities Services 9 N.- 0 0 Prioritize public parkland dedication as a condition of new residential development, allowing the use of in lieu fees only where parkland dedication is not feasible, to ensure a public park system available to the entire community. Continue to provide programming and services for seniors, including active programs, classes, and activities and outings, adjusting programming based on needs and preferences, particularly as Diamond Bar's residents age. Address the recreational needs of all children and adults, including persons with disabilities, seniors, and dependent adults, be addressed in recreational facility planning efforts. Continue to provide residents of all ages to high quality local educational facilities and learning opportunities in cooperation with the Walnut Valley and Pomona Unified School Districts (WVUSD and PUSD, respectively), the Los Angeles County library system, and community organizations. Continue sponsoring and promoting events and cultural activities that bring the community together in different locations throughout the city. See Public Facilities and Services Chapter Goal PF-G-3. Community Development On November 12, 2025, the City hosted a Senior Health Day which provided aging resources, health checks, and free information to approximately 250 local seniors at the Diamond Bar Center On January 21, 2025, the 10.23-acre property located at 22601 Sunset Crossing Road was transferred to the City at no cost by a Transfer Agreement Facilities Use Agreement. This property combined with the adjacent City -owned 2.78-acre site will create a 13-acre park site that has the potential to be developed into a community park with amenities for residents of all ages, interests and activity levels. The Walnut Valley Unified School District's digital billboard will be located on an existing, developed Walnut Valley Unified School District property, and avoids the displacement of existing land uses or the need for new infrastructure and supports the continued efficient use of an established institutional site. The project establishes a cooperative public —public partnership between the City and the School District by generating ongoing lease revenue for WVUSD to help support educational programs and facility improvements, while also providing a community benefit to the City through dedicated on -screen time for public service announcements. This allocation would allow the City to disseminate important community information and emergency notifications at no cost, strengthening interagency collaboration and enhancing public communication. The City Council approved the project on December 16, 2025. City staff continues to organize and update City-wide special events such as the Windmill Lighting, Veterans Day, Corporate Showcase, and Wedding & Event Expo in order to promote community enrichment and the business community. Parks & Recreation Parks & Recreation Community Development Parks & Recreation Page 28 of 50 Page 44 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Goals Will serve letters from outside agencies are required for building Ensure that public facilities and services, including water, permit issuance to show that adequate facilities are or will be Public Facilities & wastewater, sewage, electricity, natural gas, and solid waste, are available to serve a proposed Accessory Dwelling Unit orCommunity PF-G-6 Services provided in a safe, efficient, and timely manner to meet the current subdivision. Development and future needs of the city. See Land Use & Economic Development Chapter Policy LU-P-5 for the update on the Rule 20A Utility Undergrounding Project. Policies — Water & Wastewater As opportunities arise, work with the Los Angeles County Public Will serve letters from the LACSD are required for building permit Public Facilities & Works Department (LACPWD) and Los Angeles County Sanitation issuance to show that adequate sewer facilities are or will be Community PF-P-37 Services District (LACSD) to ensure that wastewater treatment conveyance available to serve a proposed Accessory Dwelling Unit or Development systems and treatment facility capacity is available to serve planned subdivision. development within Diamond Bar. 6. Public Safety POLICY # CHAPTER GOALS & POLICIES STATUS �=`� DEPARTMENT PUBLIC SAFETY The purpose of this Chapter is to identify the natural and man-made public health and safety hazards that exist within the City, and to establish preventative and responsive policies and programs to mitigate their potential impacts, particularly in light of our unique environmental, seismic, and topographic conditions. This Chapter also addresses the excellent public safety services provided by the L.A. County Sheriff's and Fire Departments, and endorses the continuation of the contract model of government for the continuation of these services. Lastly, the Public Safety Chapter addresses noise and serves to limit the exposure of the community to excessive noise levels. The Goals and Policies emphasize partnerships with local, regional and State agencies to ensure the City's readiness for public safety threats through action plans • educational efforts. SEISMIC AND GEOLO Goals In 2025, the City partnered with public safety partners, including Los Angeles county Sheriff's Department, Los Angeles county Fire Partner with the Los Angeles County Fire and Sheriff's Departments Department, and Inland Valley humane Society to present five public in community education efforts aimed at preventing potential loss of town -hall style meetings. Topics included an overview of the City's Community Relations PS-G-1 Public Safety life, physical injury, property damage, public health hazards, and public safety programs and budget, crime prevention, wildfire Division nuisances from seismic ground shaking and other geologic hazards prevention, emergency preparedness, and animal care and control. such as landslides and mudslides. Each meeting also included opportunities to meet public safety officials, ask questions, and receive valuable informational resources. Policies Page 29 of 50 Page 45 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT PS-P-2 PS-P-4 Public Safety Public Safety FLOOD HAZARDS AND PROTECTION Goals PS-G-2 Public Safety Require areas identified as having significant liquefaction potential (including secondary seismic hazards such as differential compaction, lateral spreading, settlement, rock fall, and landslide) to undergo site -specific geotechnical investigation prior to development and to mitigate the potential hazard to a level of insignificance or, if mitigation is not possible, to preserve these areas as open space or agriculture. Figure 7-3 (Page 7-8 of the Public Safety Element) shows areas where historical occurrence of liquefaction, or local geological, geotechnical, and groundwater conditions indicate a potential for permanent ground displacements. Carry out a review of City -owned critical facilities that may be vulnerable to major earthquakes and landslides and develop programs to upgrade them. Implement measures aimed at preventing the potential for loss of life, physical injury, property damage, public health hazards, and nuisances from the effects of a 100- year storm and associated flooding. The City implements this engineering standard on all grading projects by requiring a site -specific geotechnical investigation to identify any hazards and to develop proper hazard mitigation as appropriate. The City regularly inspects and evaluates its facilities and infrastructure. In 2025, the City consulted with a civil engineering firm to design roadway stabilization plans for a damaged section of Diamond Bar Boulevard, between Cold Spring Lane and Crooked Creek Drive. The plans will be finalized in 2026, and the conditions will be continuously monitored until construction funding is secured. The City prepared a comprehensive update to the City's Hazard Mitigation Plan (Plan) with the assistance of a Federal Emergency Management Agency (FEMA) grant, which was adopted by the City Council and approved by FEMA July 19, 2022. The Plan Update includes an all -hazards summary of potential risks to the City from earthquakes, fires, floods, severe storms, and other natural disasters. In 2025, City staff submitted a grant request to FEMA/CaIOES to fund the development of the next five-year update, with an expected completion date of 2027-2028. The Plan, in concert with the City's Emergency Operations Plan (EOP), can eventually be used to support resilient planning, mitigation, reconstruction strategies, and response efforts to climate conditions and incidents impacting the community. The Plan review process included a public comment period, including initial submission and review by FEMA. Very High Severity Fire Zones have been mapped throughout the City hillside areas requiring new construction to be fire-resistant at exterior surfaces exposed to wildland areas. Public Works Public Works Public Works Page 30 of 50 Page 46 of 328 POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT Also applies to Public Safety Chapter goals PS-G-3 and PS-G-8 and policies PS-P-7, PS-P-38, PS-P-39, and PS-P-44 Page 31 of 50 Page 47 of 328 Policies PS-P-7 PS-P-8 PS-P-9 PS-P-12 PS-P-13 FIRE HAZARDS Goals PS-G-3 Policies — General PS-P-14 Public Safety Public Safety Public Safety Public Safety Public Safety Public Safety Public Safety Work with the Federal Emergency Management Agency (FEMA) as needed to ensure that the City's floodplain information is up to date with the latest available hydrologic and hydraulic engineering data. Continue to implement flood control programs, such as the City's Grading and Floodplain Ordinances, that reduce flood hazards to comply with State flood risk management requirements. Consider the impacts to health and safety from potential flooding on future development in flood -prone areas, including those identified as being within the 100- or 500-year floodplains. Require installation of protective structures or other design measures to protect proposed building and development sites from the effects of flooding in these areas. Figure 7-4 (Page 7-12 of the Public Safety Element) shows flood zones in and around the Planning Area based on FEMA's 2016 flood hazard data. As part of the Capital Improvement Program, consider and incorporate flood control improvements identified in the drainage master plan that specifies funding and timing of prioritized improvements. Coordinate the City's Capital Improvement Program with planned County improvements. As resources become available, reduce the flooding impact of a storm event by enhancing the city's green infrastructure system to complement the gray infrastructure system where feasible. Partner with the Los Angeles County Fire Department and affiliated agencies to implement hazard mitigation plans and community education efforts aimed at preventing the potential for loss of life, physical injury, property damage, public health hazards, and nuisances from wildland and urban fires. Educate the public about fire hazards and fire prevention. Work with the County of Los Angeles Fire Department and CAL FIRE to disseminate information on fire weather watches and fire risks and encourage all Diamond Bar residents to engage in risk reduction and fire preparedness activities. See Public Safety Chapter goal PS-G-2 The City routinely implements flood control programs that reduce hazards to comply with State requirements. The City considers the impacts of potential flooding on future development in flood -prone areas and requires mitigation measures, as appropriate. See Land Use & Economic Development Chapter Policy LU-P-S for information about the flood control and drainage improvement projects constructed in 2025. See Community Character & Placemaking Chapter Goal CC-G-S for information about the green street component included in the scope of the Diamond Bar Boulevard Complete Streets Project. See Public Safety Chapter goal PS-G-2 The City continues to expand upon public education and outreach efforts to educate residents with a comprehensive approach to fire and weather -related hazards, through a variety of platforms such as City's website, monthly DBConnection newsletter, public presentations, emergency alert system, and informational videos. The information, in collaboration with City and Public Safety partners with Los Angeles County Sheriff and Fire Departments, is aimed at Public Works Public Works Public Works Public Works Public Works City Manager's Office City Manager's Office Page 32 of 50 Page 48 of 328 The Los Angeles County Fire Department maintains improving public safety preparedness efforts, increase resident information on family fire preparedness plans and risk awareness, and ensure compliance with State and County Public reduction measures such as vegetation management. Health Orders. The Los Angeles County Fire Department also has an active fire brush clearance program that incorporates inspections from local fire stations in areas of know fire danger to ensure that residents are aware of mitigation measures they can implement on their property. The City, in collaboration with Los Angeles County Office of Emergency Management (OEM), County of Los Angeles Fire Department, and Los Angeles County Sheriff's Department, finalized and implemented the Genasys Project in 2024 — where the City of Diamond Bar and cities throughout the County have pre -designated fire evacuation zones that can be used to communicate to residents in the event of a fire emergency requiring evacuation. The system is complete and the zone information has been used for testing and preparedness efforts during summer 2025 SCE Public Safety Power Shutoff (PSPS) activations. Also applies to Public Safety Chapter goal PS-G-9 and policies PS- P-18 and PS-P-42 See Land Use & Economic Development Chapter Policy LU-P-5 for the update on the Rule 20A Utility Undergrounding Project. Prior to building permit issuance, all residential projects located in Ensure adherence to applicable Fire and Building Codes, including the High Fire Hazard Severity Zone are required to submit landscape standards for minimum road widths, access and clearance for plans designed to comply with the requirements of the Los Angeles Community PS-P-15 Public Safety emergency vehicles, and the identification of all roads, streets, and County Fire Department's Fuel Modification Plan Guidelines in terms Development major public buildings in a manner that is clearly visible to fire of plant selection, placement and maintenance. The final landscape protection and other emergency vehicles. and fuel modification plans are submitted to the Los Angeles Fire Department for review and approval. For privately -owned property within areas designated for Prior to building permit issuance, all residential projects located in development that are subject to high wildfire risk, condition approval the High Fire Hazard Severity Zone are required to submit landscape of development upon the implementation of measures to reduce plans designed to comply with the requirements of the Los Angeles Community PS-P-16 Public Safety risks associated with that development, including, but not limited to, County Fire Department's Fuel Modification Plan Guidelines in terms Development fuel modification plans and Fire Code requirements in effect at the of plant selection, placement and maintenance. The final landscape time of project approval. and fuel modification plans are submitted to the Los Angeles Fire Department for review and approval. Work cooperatively with the County of Los Angeles Fire PS-P-18 Public Safety Department, CAL FIRE, and fire protection agencies of neighboring See Public Safety Chapter policy PS-P-14 City Manager's Office jurisdictions to address regional wildfire threats. Page 33 of 50 Page 49 of 328 Policies — Fire Hazard Severity Zones & State Responsibility Areas PS-P-19 PS-P-20 PS-P-21 1:M:&% PS-P-23 Public Safety Public Safety Public Safety Public Safety Public Safety Maintain and update the City's High Fire Hazard Severity Zones map consistent with changes in designation by CAL FIRE to ensure that the County of Los Angeles Fire Department is protecting the community from wildland-urban fires as future development takes place. Prior to permit approval, ensure that all new development located in a Very High Fire Hazard Severity Zone or a State Responsibility Area (SRA) is served by adequate infrastructure, including safe access for emergency response vehicles, visible street signs, and water supplies for fire suppression. Collaborate with the County of Los Angeles Fire Department to ensure that properties in and adjacent to High or Very High Fire Hazard Severity Zones as indicated in Figure 7-6 are adequately protected from wildland fire hazards in a manner that minimizes the destruction of natural vegetation and ecosystems through inspection and enforcement. Update Figure 7-6 as new information becomes available from CAL FIRE. Support the County of Los Angeles Fire Department's Provision of weed abatement and brush thinning and removal services in High and Very High Fire Hazard Severity Areas in order to curb potential fire hazards. Where development is proposed within High or Very High Fire Hazard Severity Zones, ensure that the County of Los Angeles Fire Department has the opportunity to review the proposal in terms of its vulnerability to fire hazards and its potential as a source of fire, including fuel modification plan review for new development or additions that are equal or greater than 50 percent of the existing square footage. HAZARDOUS MATERIALS AND OPERATIONS Policies On sites with known contamination of soil and groundwater, work with State and local agencies to continue to identify and compel cleanup of such sites to ensure that construction workers, future occupants, the public, and the environment are adequately PS-P-25 Public Safety protected from hazards associated with contamination. The City may reference the State Water Resources Control Board's Geotracker database and the California Department of Toxic Substances Control's EnviroStor database to identify potentially hazardous sites. Figure 7-8 (Page 7-26 of See Public Safety Chapter Policy PS-P-14. See Public Safety Chapter Policy PS-P-14. See Public Safety Chapter Policy PS-P-14. See Public Safety Chapter Policy PS-P-14. Prior to building permit issuance, all residential projects located in the High Fire Hazard Severity Zone are required to submit landscape plans designed to comply with the requirements of the Los Angeles County Fire Department's Fuel Modification Plan Guidelines in terms of plant selection, placement and maintenance. The final landscape and fuel modification plans are submitted to the Los Angeles Fire Department for review and approval. City staff is continuing to monitor the progress of groundwater remediation of the vacant lot at 23671 Golden Springs Drive. The owner is currently working with the California Regional Water Quality Control Board to test and cleanup releases from underground gas storage tanks where the former Chevron gas station previously occupied the site. City Manager's Office Community Development Community Development Community Development Community Development Community Development Page 34 of 50 Page 50 of 328 SHERIFF, FIRE, AND EMERGENCY SERVICES Goals PS-G-5 PS-G-6 PS-G-7 Policies PS-P-29 Public Safety Public Safety Public Safety Public Safety the Public Safety Element) shows sites identified through these databases in 2019. Maintain safety services that are responsive to citizens' needs to ensure a safe and secure environment for people and property in the community. Support community -based policing partnerships to enhance public awareness of crime prevention and strengthen the relationship between the Los Angeles County Sheriff's Department and neighborhoods throughout the city. Provide effective emergency preparedness and response programs. Coordinate with the Los Angeles County Sheriff's Department for review of applications for new development and for the intensification of existing development, ensuring that review is consistent with Crime Prevention Through Environmental Design (CPTED) principles. The City continues to fund and administer the Flock Safety Automated License Plate Reader (ALPR) system as an investigative tool to close out cases and prevent criminal activity. The City has also invested $50,000 into additional burglary prevention/suppression patrols, which in partnership with the Los Angeles Sheriff's Department is designed to focus on burglary suppression activity to reduce property crimes in residential and commercial areas in the City. See Public Safety Chapter Goal PS-G-I The City continued to distribute information through its "Let's Talk Public Safety" program, primarily through law enforcement safety blogs and videos. New to 2025, the City collaborated with the County of Los Angeles Sheriff's Department, Los Angeles County Fire Department, and Inland Valley Humane Society to host a series of "Meet Your Public Safety Services Providers" events. The four informational meetings provided residents an opportunity to hear from the City's local public safety providers, including programs and services such as Neighborhood Watch, Business Watch, fire prevention and emergency preparedness, animal licensing efforts and living with wildlife. Additionally, The "Coffee with a Cop" meetings are held once a month at locations through the City, where residents and businesses can talk with a member of the Sheriff's Department about crime and other law enforcement techniques. Also applies to Public Safety Chapter Policy PS-P-30 See Public Safety Chapter Policy PS-P-37 See Public Safety Chapter Goal PS-G-6 City Manager's Office City Manager's Office City Manager's Office City Manager's Office Page 35 of 50 Page 51 of 328 Continue to promote the establishment of neighborhood watch and PS-P-30 Public Safety business watch programs to encourage community participation in See Public Safety Chapter Goal PS-G-6 City Manager's Office the patrol of neighborhoods. The City continues to expand upon its emergency preparedness and response capabilities through training, testing, and exercises. The dedicated EOC provides the City with added flexibility to coordinate and respond to emergencies, provide redundant communications to public safety agencies, and enable added communications to residents. City Hall also has a backup power generator to ensure Maintain area -wide mutual aid agreements and communication critical systems are operational in the event of a prolonged PS-P-37 Public Safety links with adjacent governmental authorities and other participating emergency outage, with redundant communications capabilities City Manager's Office jurisdictions. including the Sheriffs Department and County Office of Emergency Management (OEM). The City participated in the annual Great California Shakeout in October 2025, and will continue efforts with additional training and exercises in collaboration with LA County OEM, local school districts, and adjoining municipalities. Also applies to Public Safety Chapter Goal PS-G-7 and Policies PS- P-40, PS-P-41, and PS-P-43 EMERGENCY AND DISASTER MANAGEMENT Goals Use the Local Hazard Mitigation Plan and Emergency Operations Plan to address mitigation and response for local hazards, including seismic hazards, flood hazards, fire hazards, hazardous materials PS-G-8 Public Safety incidents, and hazardous sites, and to plan for the protection of See Public Safety Chapter Goal PS-G-2 City Manager's Office critical facilities (i.e., schools, hospitals), disaster and emergency response preparedness and recovery, evacuation routes, peak load water supply requirements, and minimum road width and clearance around structures. Conduct emergency and disaster management planning in a PS-G-9 Public Safety collaborative manner with State and local agencies and neighboring See Public Safety Chapter Policy PS-P-14 City Manager's Office jurisdictions, while striving for self-sufficiency in City -level emergency response. Policies Maintain, review, and update Diamond Bar's Local Hazard PS-P-38 Public Safety Mitigation Plan as needed to take into account new hazard See Public Safety Chapter Goal PS-G-2 City Manager's Office conditions in the Planning Area and new emergency management techniques. PS-P-39 Public Safety Adopt, implement and update as necessary the Local Hazard See Public Safety Chapter Goal PS-G-2 City Manager's Office Mitigation Plan to develop strategies to address changing risks from Page 36 of 50 Page 52 of 328 PS-P-40 PS-P-41 PS-P-42 PS-P-43 PS-P-44 NOISE Policies PS-P-49 Public Safety Public Safety Public Safety Public Safety Public Safety Public Safety flood, drought, fire, landslides, seismic activity, hazardous materials, and other potential hazards, including strategies related to monitoring, emergency preparedness, development policies, conservation, vulnerable populations, and community resilience. Continue to coordinate the City's emergency preparedness and response plans and operations with the State Office of Emergency Management, Los Angeles County, schools, and other neighboring jurisdictions. Maintain and expand as necessary community emergency preparedness resources including personnel, equipment, material, specialized medical and other training, and auxiliary communications. Continue to disseminate public information and alerts regarding the nature and extent of possible natural and manmade hazards, resources identifying measures residents and businesses can take to prepare for and minimize damage resulting from these hazards, citywide response plans, and evacuation routes. Require all City staff to be adequately trained to respond to emergency situations, and conduct regular emergency preparedness drills with local organizations including the Los Angeles County fire and Sheriff's departments. Leverage pre- and post -disaster assistance programs to support resilient planning, mitigation, and reconstruction strategies that consider future climate conditions, such as the California Governor's Office of Emergency Services' Hazard Mitigation Grant Program and California Disaster Assistance Act. Ensure that detailed site -specific noise analysis, including the identification of noise mitigation measures, be prepared for all development proposals located where project noise exposure would be other than normally or conditionally acceptable as specified in Table 7-1. With mitigation, development should meet the allowable exterior and interior noise exposure standards established in the Noise Control Ordinance. See Public Safety Chapter Policy PS-P-37 See Public Safety Chapter Policy PS-P-37 The City issues regular emergency preparedness updates and information on its website, public access television channels, social media accounts, print newsletters, and e-subscription services/Civic Ready notification service. Emergency preparedness topics are also covered in the eight -meeting City Government Explained series, four -meeting Let's Talk Public Safety series, and in Council presentations throughout the year. See Public Safety Chapter Policy PS-P-14 See Public Safety Chapter Policy PS-P-37 During grading and construction activities, development projects are required to properly muffle all construction equipment to reduce noise levels. City Manager's Office City Manager's Office Community Relations Division City Manager's Office City Manager's Office Public Works and Community Development PS-P-52 Public Safety Ensure that noise attenuation facilities are installed as feasible in all See Land Use & Economic Development Chapter Policy LU-P-14. Public Works noise -sensitive areas impacted by County, State, or federal Page 37 of 50 Page 53 of 328 highways through coordination with Caltrans and the Federal The SR57/60 Confluence Project will install sound walls wherever Highway Administration. applicable and necessary within the limits of the project. 7. Community Health & Sustainability POLICY # CHAPTER GOALS & POLICIES STATUS DEPARTMENT COMMUNITY HEALTH & SUSTAINABILITY The Goals and Policies in this Chapter identify strategies to facilitate healthy and active lifestyles, social connections and celebrating diversity, access to healthy food, and climate change resilience. Many of these strategies could be incorporated into existing or future City programs and Development Code standards. ACTIVE LIFESTYLE Goals Community Health & Promote the use of public parks, recreational and other spaces for Dozens of enrichment classes and athletic opportunities are CHS-G-3 Sustainability healthy exercise and physical activity. provided throughout the year at local parks by the City, independent Parks & Recreation contracts, or non-profit organizations. Policies On January 21, 2025, the 10.23-acre property located at 22601 Sunset Crossing Road was transferred to the City at no cost by a Community Health & Strive to ensure that all areas of the community have an equal Transfer Agreement Facilities Use Agreement. This property CHS-P-1 Sustainability distribution of public parks and public recreational facilities to combined with the adjacent City -owned 2.78-acre site will create a Parks & Recreation maximize access. 13-acre park site that has the potential to be developed into a community park with amenities for residents of all ages, interests and activity levels. SOCIAL CONNECTION Goals Enhance cultural and generational diversity and social connections Community Health & through opportunities for volunteerism and civic engagement, public The City provides annual City-wide special events and senior CHS-G-5 Sustainability gathering places, public art, family -friendly activities, and events programming that support teens looking to volunteer and seniors Parks & Recreation that connect residents to one another, helping them to stay socially interested in intergenerational opportunities. active in the community. Community Health & Provide safe and welcoming opportunities for meeting and The Diamond Bar Center and Heritage Park serve as "home" for six CHS-G-6 Sustainability gathering that encourage face-to-face interactions between people. unique senior clubs who meet regularly throughout the week for both Parks & Recreation organized activity and leisurely gatherings. Policies Community Health & Continue to support and promote citywide events that integrate Many City-wide special events include partnerships with both local CHS-P-7 Sustainability families, schools, and the greater community. high schools and a middle school who are responsible for an active Parks & Recreation role in the event. Page 38 of 50 Page 54 of 328 POLICY # I CHAPTER I GOALS & POLICIES I STATUS I DEPARTMENT Community Health & Encourage and provide volunteer opportunities for residents to The Parks & Recreation Department offers volunteer opportunities CHS-P-9 Sustainability engage and support a wide variety of events and activities. for teens at events, seniors at the Diamond Bar Center, and adults Parks & Recreation through the youth sports programs. Support the provisions of spaces, programs and facilities across the The City provides annual live Concerts in the Park at no charge. CHS-P-13 Community Health & community to provide opportunities for artistic and cultural These performances including a variety of genres and entertainment Parks & Recreation Sustainability engagement and expression for all members of the Diamond Bar for all ages. community. Encourage the development of "destinations" —such as the clusters CHS-P-14 Community Health & of commercial uses that draw residents from the entire community See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Community Sustainability into the Neighborhood Mixed Use, the Transit -Oriented Mixed Use, Development and the Town Center focus areas. CHS-P-15 Community Health & Encourage the establishment of gathering areas in new See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. Community Sustainability neighborhoods. Development HEALTHCARE & HUMAN SERVICES HEALTHY FOOD Policies CHS-P-21 CHS-P-24 Community Health & Sustainability Community Health & Sustainability Promote healthy food and beverages at City -sponsored events, programs, and recreation activities. Ensure that safe, clean drinking water is available for the public at all City -owned buildings where public programs occur. Explore opportunities as they arise to incorporate community gardens into City parks and open space areas, and encourage the Diamond Bar Community Garden and other organizations to facilitate the development, administration, and operation of additional community gardens in the City. Clean drinking water is available at all City facilities and a variety of food trucks typically provide an array of food and beverage options at City -sponsored special events. Staff is also provided with clean drinking water at events. Water bottle filling stations are available at the Diamond Bar Center and also included at parks when replacing the previous drinking fountain. Compost and mulch is available year-round at Sycamore Canyon Park to support community members in maintaining their home gardens. This resource is part of the City's commitment to promoting sustainable gardening practices. To further educate residents, the City offers workshops at community events focused on composting techniques and organic gardening methods. Additionally, the monthly EnviroLink newsletter provides valuable information and resources on these topics, helping residents learn how to effectively use compost and mulch while reducing organic waste. These efforts aim to empower the community with the knowledge and tools needed for sustainable gardening. Parks & Recreation City Manager's Office Page 39 of 50 Page 55 of 328 PUBLIC HEALTH AND ENVIRONMENTAL JUSTICE Policies CHS-P-30 Community Health & Sustainability Support a better informed and civically engaged community by making information available both in print and electronic format, and, to the extent possible, provide this information in the languages predominantly spoken in the community. CLIMATE CHANGE AND GREENHOUSE GASES Goals CHS-G-13 CHS-G-14 Community Health & Promote energy efficiency and conservation in the community Sustainability Community Health & Encourage waste reduction and diversion practices to meet State Sustainability targets and reduce GHG emissions. The City's efforts to keep community members informed and engaged include using various communication channels to give residents the choice of how they receive information and participate in the decision -making process. These channels include a monthly printed newsletter mailed to all Diamond Bar addresses, a weekly electronic newsletter, Weekly Highlights, sent via email or text to subscribers, a mobile app, two-way engagement on Facebook, and regular postings on Instagram and YouTube. In 2025, the City expanded its improvement in communication by making the City's government access channel, Diamond Bar TV, (DBTV) available for free streaming on Roku and the Cablecast app. Previously only available on Spectrum Cable Channel 3 or Frontier ROS television Channel 47, DBTV is one of the many ways the City shares information about City programs, projects and services with the community. Programming on DBTV include City Council meeting replays, local business spotlights, public safety videos, and the DB Minute video shorts series that covers various City services and programs. The City has partnered with the San Gabriel Valley Council of Governments (SGVCOG) to increase public awareness of energy conservation programs and best practices from Southern California Edison and the Gas Company. Information is distributed through the City's EnviroLink newsletter, as well as direct communication from partner agencies and utility providers. The City complies with all State laws governing waste management and recycling. The City continues to maintain its economic incentive programs, in partnership with its waste haulers, as described in prior years, to reduce waste and increase diversion under the new waste hauler contracts that began in September 2025. During the transition to the new contracts, the City and its waste haulers implemented an education and outreach campaign to re- educate residents on proper sorting practices to increase diversion and reduce contamination. Outreach efforts included print and electronic materials, in -person and virtual workshops, and ongoing contamination monitoring. Community Relations Division City Manager's Office City Manager's Office Page 40 of 50 Page 56 of 328 Policies — Energy Efficiency & Conservation CHS-P-39 CHS-P-44 Community Health & Sustainability Support Southern California Edison (SCE) and Southern California Gas Company's (SoCalGas) efforts to increase public awareness of energy conservation technology and best practices. Community Health & Promote energy conservation and retrofitting of existing buildings Sustainability through the implementation of the Green Building Codes. Policies — Waste Reduction & Recycling CHS-P-46 CHS-P-47 Community Health & Sustainability Community Health & Sustainability In order to achieve compliance with the source reduction goals set forth under Assembly Bill (AB) 939 amendments thereto, incorporate solid waste diversion goal performance standards into the contracts with the City's franchise waste haulers, and enforce the City's Construction and Demolition Waste Ordinance. Reduce the disposal of household hazardous wastes in landfills through continued cooperation with waste pick-up service providers, the County Sanitation Districts, and the Los Angeles County Department of Public Works in the provision of curbside pick-up and annual household waste round up events. The City also continues to provide waste reduction tips through its monthly electronic environmental newsletter. In addition to its ongoing student education programs with Discovery Cube that focus on recycling and waste reduction, the City partnered with Algalita Marine Research to offer an additional educational experience for youth, focused on plastic pollution and prevention strategies. The City has partnered with the San Gabriel Valley Council of Governments (SGVCOG) to increase public awareness of energy conservation technologies and best practices from Southern California Edison and the Gas Company. Information is distributed through the City's Envirolink newsletter, as well as direct communication from partner agencies and utility providers. The Building & Safety Division implements CALGreen by requiring all construction projects to meet State requirements. This is done through requiring all waste hauling by the City's franchise hauler or to a recycling facility, requiring low emitting vehicle parking for new commercial projects, limiting VOCs, inspecting erosion control, and requiring low water usage in plumbing. The City Manager's Department has been actively working on new solid waste franchise agreements, launched in 2025. To meet the source reduction goals of Assembly Bill (AB) 939 and its amendments, the City is incorporating solid waste diversion performance standards into the contracts by standardizing monthly and annual reporting with franchise waste haulers. This initiative supports the City's commitment to compliance and sustainability. The City is also strengthening its Construction and Demolition Waste Ordinance by updating applications and improving intake and processing procedures, further emphasizing responsible waste management practices. The City is actively working to reduce household hazardous waste (HHW) disposal in landfills by collaborating with waste service providers, the County Sanitation Districts, and the Los Angeles County Department of Public Works. These efforts include organizing, supporting, and promoting annual HHW round -up events. The City enhances these initiatives with the Door -to -Door curbside collection program through waste hauler and provides information about local drop-off locations for common HHW as alternatives to curbside pickup or the annual County collection event in Diamond Bar. The City promotes nearby County HHW events City Manager's Office Community Development City Manager's Office City Manager's Office Page 41 of 50 Page 57 of 328 hosted in other cities. The City held two e-waste collection events, one in April and another in August, and plans to expand to three e- waste events next year to further reduce environmental impacts. The City continues to monitor and support the collection of batteries and light bulbs at the local Ace Hardware. The City is dedicated to promoting the safe disposal of household hazardous waste (HHW) through education and incentives. We focus on raising awareness about proper disposal methods, including the local Ace Hardware takeback program, and encouraging responsible waste management. CHS-P-48 Community Health & Continue to promote the safe disposal of household hazardous The City supports several collection programs and events, including City Manager's Office Sustainability waste through public education and incentives. the At Your Door curbside collection program, the annual County HHW collection event in Diamond Bar (held in March), and nearby County -hosted events in other cities. A local HHW recycling and disposal guide has been created and is distributed at events, community centers, and collection partners like Ace Hardware, AutoZone, and Sherwin-Williams. The guide is also included in the 2025 City Calendar mailed to all residents. The City is committed to promoting source reduction and recycling through targeted education for residential, commercial, and industrial sectors. Educational efforts include outreach campaigns delivered through waste hauler billing inserts, City newsletters, social media, the City's website, community events, and workshops. Continue to educate residential, commercial, and industrial Waste haulers also provide in -person and virtual workshops focused CHS-P-49 Community Health & generators about source reduction and recycling programs and on proper sorting practices and contamination minimization. City Manager's Office Sustainability encourage their participation in these programs through promotional campaigns and incentives. To encourage participation, the City offers free incentives such as food waste kitchen pails, compost bins, and used oil collection kits. In addition, the City has extended its contract with its waste and recycling education provider, Discovery Cube, and launched a new environmental education partnership with Algalita Marine Research, focusing on plastic waste, pollution, and prevention strategies. In our ongoing efforts to minimize edible food waste, the City contracted consultants are actively encouraging generators of edible Encourage generators of edible food to have contracts or food to establish contracts or agreements with food rescue CHS-P-50 Community Health & agreements with food rescue organizations to minimize edible food organizations. This initiative aims to divert edible food from being City Manager's Office Sustainability from being disposed of or destroyed. needlessly disposed of or destroyed. The City is facilitating the establishment of partnerships between generators and food rescue organizations, fostering a collaborative approach to addressing food waste challenges. Page 42 of 50 Page 58 of 328 CHS-P-51 CHS-P-52 CHS-P-53 Community Health & Sustainability Community Health & Sustainability Community Health & Sustainability Policies — Climate Change Resiliency CHS-P-57 Community Health & Sustainability Encourage residents and businesses to compost leaves, grass clippings, food waste, and other organic materials by promoting existing food waste pickup services, residential waste hauler rate composting discounts, and residential backyard composting. Collaborate with the City's contract waste haulers to educate and encourage residents and businesses about waste reduction strategies. Support and cooperate with County and State regulatory agency efforts to require commercial and industrial generators to develop and implement a source reduction and recycling plan tailored to their individual waste streams. Encourage water conservation, drought -tolerant landscaping and the use of greywater and reclaimed and recycled water, where appropriate, with a view to reducing water use. The City actively encouraged and re-educated residents and businesses on composting, proper sorting, and contamination reduction through a Citywide education campaign in preparation for the waste hauler transition scheduled for September 2025. Information on hauler economic incentive programs, sorting guides, and additional disposal options was mailed to every resident and business in the City, providing comprehensive details on available waste -related programs. To further expand outreach, waste haulers hosted a series of in - person and virtual workshops to reinforce proper sorting practices and program awareness. The City also continues to incorporate composting and food waste reduction information into its monthly electronic environmental newsletters and community events. The City works closely with its franchised waste haulers to educate and motivate residents and businesses to adopt effective waste reduction strategies. As part of the hauler transition, businesses are now required to source -separate recyclables from trash. To support this effort, WM mailed sorting guides and additional program information to each business. During the rollout of the program, businesses received additional education focused on proper recycling practices and contamination reduction and one-on-one support in implementing these practices. Through continued collaboration, the City ensures that residents and businesses receive consistent waste reduction information through newsletters from both the haulers and the City, as well as through site visits, phone calls, and emails. The City remains committed to strengthening these partnerships and fostering a culture of responsible waste management throughout the community. The City supports and cooperates with County and State regulatory agencies to implement measures that require commercial and industrial generators to develop and execute source reduction and recycling plans tailored to their unique waste streams. Our collaborative efforts aim to ensure compliance with regulations, where applicable, while promoting sustainable waste management practices among businesses. During project review, the Planning Division ensures that the plant palette is diverse, Southern California native and drought -tolerant vegetation is utilized, and that the planting and irrigation plans comply with the City's Water Efficient Landscaping Ordinance. Also, City Manager's Office City Manager's Office City Manager's Office Community Development Page 43 of 50 Page 59 of 328 reclaimed water is required for nonresidential irrigation systems where available. See Resource Conservation Chapter Goal RC-G-6. Community Health & C As resources become available, increase the efficiency of water CHS-P-59 ustainability usage in public places, such as irrigation in public parks, and utilize See Community Conservation Chapter Policy CC-P-5. Public Works drought -tolerant landscaping in City parks and streetscapes. 8. Housing — 2021-2029 (6th Cycle) Housing Element Program Evaluation PROGRAM # OBJECTIVES STATUS HOUSING The Housing Element, which has been certified by the California Department of Housing and Community Development (HCD) on October 5, 2022, identifies and makes provisions for existing and future housing needs. While most of these enabling policies require the participation of the private sector, the City also actively participates in implementation by budgeting a portion of its annual Community Development Block Grant (CDBG) allocation and state Permanent Local Housing Allocation (PLHA) funds to administer the City's Home Improvement Program (HIP). The HIP provides zero -interest deferred loans of up to $30,000 to eligible low-income households to perform essential home repairs and improvements. Low-income households are also eligible to participate in the Los Angeles County Community Development Commission's CDBG-funded Home Ownership Program (HOP) for first-time homebuyer assistance. The City will file the Housing Element Annual Progress (APR) with HCD and Office of Planning and Research (OPR) by April 1, 2026, which outlines progress on the implementation of the adopted 2021-2029 (61" Cycle) Housing Element. The table below summarizes the 2021-2029 Housing Element housing programs offered through the Community Development Department along with program objectives, accomplishments, and implementation status. The City continues to operate the code enforcement program. This program is successful and is being continued. Code enforcement cases have increased in Continue to implement the code enforcement program, and direct eligible number and complexity due to factors including aging housing stock and the households to available rehabilitation assistance to correct code violations. declining financial resources of longtime residents. The code enforcement 1. Residential Neighborhood Improvement Provide focused code enforcement and rehabilitation assistance for 5 to 6 officers and building inspectors are typically the first public officials to learn Program households during the planning period in neighborhoods evidencing which homeowners lack the financial resources to correct property maintenance concentrations of deteriorating units. violations, and in the process, become aware of other deferred maintenance issues. The officers carry copies of the City's Home Improvement Program (HIP) brochures and inform homeowners potentially in need of assistance that the City offers no -interest, deferred loans for essential home repairs. The City allocates at least $100,000 of its annual CDBG award to the Home Improvement Program. The HIP provides zero -interest loans of up to $30,000 to low- and very -low-income homeowners, which do not need to be repaid Improve neighborhoods evidencing deferred maintenance through property unless the home is sold or refinanced. There is a waiting list of pre-screened 2. Home Improvement Program maintenance and rehab. Provide minor repair and rehabilitation to 4 units applicants, and HIP loans are processed in the order received. annually. The HIP Program Policies are highlighted below: • The maximum loan amount for single-family detached homes increased from $20,000 to $30,000. Page 44 of 50 Page 60 of 328 PROGRAM # OBJECTIVES STATUS • Owner -occupants of condominiums that meet the household income requirements are now eligible for HIP loans for up to $20,000, provided that PLHA funds are available. The maximum loan amount is lower than the cap for single-family detached homes because costlier improvements, such as roof maintenance and exterior repairs, are the responsibility of the condominium HOAs, not the individual homeowners. • PLHA funds may be used to issue loans to households (both single-family detached and condominium) earning up to 150% of the Area Median Income (AMI) for L.A. County. CDBG funds continue to be restricted to owner - occupied households of single-family detached housing earning no more than 80% of AMI. • A minimum loan amount of $10,000 is now required. Previously, no minimum was specified. Establishing a minimum loan amount encourages homeowners to address more improvements at once, and provides economies of scale with respect to the administrative costs associated with processing loans. The HIP is successful in improving housing conditions and is being continued at available funding levels. This program is beneficial in reducing problems such as overpayment and 3. Section 8 Rental Assistance Program Continue to direct eligible households to the County Section 8 program. overcrowding. City continues to coordinate with the County on the Section 8 program. Handouts are available at the public counter and contact information is regularly provided to requestors. The program is being continued. Diamond Bar contains only one assisted housing project, the 149-unit Seasons Apartments (formerly Heritage Park) for senior citizens. This project was constructed in 1988 and was originally financed under the Los Angeles County Multi -Family Mortgage Revenue Bond program. The project was refinanced in November 1999 under the California Community Development Authority's Multi- 4. Preservation of Assisted Housing Preserve 100 percent of the 149 low- and moderate -income units in The Family Housing Re -funding Bond, and was transferred to the Corporate Fund Seasons Apartments. for Housing, a non-profit organization. According to the terms of the new bond agreement, income restrictions for residents and corresponding rent limits were set. For the duration of the bond, which expires December 2, 2034, all units will be affordable: 30 units (20%) will be very -low-income, 82 units (55%) will be low- income, and 37 units will be moderate -income (defined as 100% AMI). All units will be preserved. Zoning for mobile home parks is successful in preserving this affordable housing 5. Mobile Home Park Preservation Continue to support preservation of the City's two mobile home parks as option and is being continued. No proposals to close the parks were submitted. important affordable housing resources. The City will continue to support preservation of its two mobile home parks as important affordable housing resources. Page 45 of 50 Page 61 of 328 PROGRAM # OBJECTIVES STATUS Advertise County's Home Ownership Program (HOP) and Mortgage Credit The City advertised these programs on the City website and will provide 6. First-time Homebuyer Assistance Certificate (MCC) and provide information to interested homebuyers. In addition, information to interested homebuyers annually via City newsletters and through Programs the City will work with realtors to make them aware of these programs. social media. In addition, the City will work with realtors to make them aware of these programs. Identify and evaluate sites suitable for new senior and workforce housing. The This program is intended to encourage affordable housing development and is City will post information on the City website during the first year of the planning being continued. The City is a member of the San Gabriel Valley Regional period regarding the City's interest in assisting in the development of senior and Housing Trust (SGVRHT), which is a joint powers authority. SGVRHT's focus is 7. Senior and Workforce Housing workforce housingprovide information on available regulatory and financial , primarily on providing funding assistance in the planning and construction of Development incentives, and assist developers in applying for funds. The City will also contact new homeless and affordable housing. The Trust provides funding and loans to local colleges and universities annually to identify potential partnership help bridge funding gaps for affordable housing projects. Land Use Policies 10 opportunities for affordable housing. and 28, which were adopted in the 2019 General Plan Update, also encourage the production of senior and workforce housing. The City has maintained adequate sites for housing development at all income levels and ensure compliance with No Net Loss requirements. In May 2022, the City entered into a Consultant Services Agreement with Torti Gallas + Partners to prepare the Town Center Specific Plan (TCSP) in the Town Center Mixed - Use focus area, which is one of the sites to accommodate the RHNA. Continual progress has been made on the Specific Plan during the planning period. The Maintain adequate sites for housing development at all income levels in 45-day public review period for the Supplemental SIR was August 25 through conformance with the RHNA and ensure compliance with No Net Loss October 10, 2025. On February 10, 2026, the Planning Commission requirements. Process Development Code amendments to provide adequate recommended approval to the City Council, and is tentatively scheduled for the 8. Land Use Element and Zoning sites to accommodate the RHNA. Update all regulations and fees on the City March 3, 2026 City Council hearing. website annually throughout the planning period. Notify water and sewer On February 4, 2025, the City rezoned the General Plan's three Mixed -Use providers immediately upon adoption of the Housing Element. designations (Town Center Mixed -Use, Neighborhood Mixed -Use and Transit - Oriented Mixed -Use focus areas) to allow residential development at a minimum density of 20 dwelling units per acre and a maximum density of at least 30 dwelling units per acre. On November 15, 2022, the City notified the water and sewer providers immediately upon adoption of the Housing Element. In December 2019, the City adopted the Comprehensive General Plan Update that created community visions and blueprint for growth and development in the City through 2040. One of the key features of the new General Plan was the Prepare handout and marketing materials encouraging mixed -use development establishment of three new Focus Areas where substantial land use changes 9. Mixed Use Development where appropriate and make it available to interested developers throughout the are planned as part of a strategy to provide walkable mixed -use activity centers. planning period. Goals and policies to promote mixed use developments are as follows: Land Use Goals 12, 14, 15, 16, 18, 19, 22, 24, 26, Land Use Policies 15, 16, 21, 23, 27, 28, 29, 35, 45; Community Character and Placemaking Goals 7, 8, 14, 17; and Circulation Goal 4. Page 46 of 50 Page 62 of 328 PROGRAM # OBJECTIVES STATUS In May 2022, the City entered into a Consultant Services Agreement with Torti Gallas + Partners to prepare the Town Center Specific Plan in the Town Center Mixed -Use focus area. The TCSP will provide the regulatory and urban design framework to establish a downtown, or "Town Center" in Diamond Bar as a walkable place with entertainment, retail, restaurants, community gathering spaces, and urban housing opportunities. This program is an important component of the City's overall strategy to revitalize older areas and expand housing production. The 45-day public review period for the Supplemental SIR was August 25 through October 10, 2025. On February 10, 2026, the Planning Commission recommended approval to the City Council, and is tentatively scheduled for the March 3, 2026 City Council hearing. See Land Use Chapter Goal LU-G-4 and Policy CC-P-21. In 2017, the City approved an amendment to the municipal code pertaining to accessory dwelling units to satisfy all of the requirements of Government Code §§65852.150-65852.2. Per AB 68 (Ting), AB 587 (Friedman), AB 671 (Friedman), AB 881 (Bloom), SB 13 (Wieckowski) that went into effect January 1, 2020. In 2021 the City adopted a subsequent amendment to ADU regulations in accordance with the new State laws. On July 16, 2024, the City adopted another Development Code Amendment for consistency with the most recent passages of AB 2221 (Quirk -Silva) and SB 897 (Wieckowski). The updated ADU Ordinances have been effective in supporting the production of ADUs and provides affordable rents to low- and moderate -income households. An ADU handout has been created which is being distributed at the public counter. The City continues to encourage accessory dwelling units and this Continue to encourage construction of ADUs through an informational handout program is being continued. 10. Accessory Dwelling Units available at City Hall and on the City website throughout the planning period. 51 building permits for ADUs totaling 38,407 square feet were issued. The City is in the early testing phase of its Pre -Approved Accessory Dwelling Unit (ADU) Program, known as DBADU, which supports the City's General Plan housing goals by streamlining ADU development and expanding housing opportunities. The program is implemented pursuant to State ADU law, including Government Code Sections 65852.2 and 65852.22, which require ministerial approval of ADUs that comply with objective standards and encourage jurisdictions to reduce regulatory barriers to ADU construction. The DBADU program allows qualified design professionals to submit ADU plans for City review and pre -approval, with the intent of creating a catalog of code -compliant designs that homeowners may use to reduce permitting time and uncertainty. To support implementation, City staff has developed a dedicated program Page 47 of 50 Page 63 of 328 PROGRAM # OBJECTIVES STATUS website and application materials, and the City is currently piloting the program with a selected firm to test workflows and review procedures before opening participation to additional professionals and releasing pre -approved plans for broader public use. The DBADU is set to be open to the public in early 2026. Continue to facilitate emergency shelters and transitional/ supportive housing On July 16, 2024, the City adopted a Development Code Amendment to allow and continue participating with LAHSA and SGVCOG on efforts to address supportive housing and low barrier navigation centers consistent with State law 11. Housing for Persons with Special Needs homelessness throughout the planning period. Process an amendment to the and to replace or modify the CUP requirement to provide greater objectivity and Development Code to allow supportive housing, low barrier navigation centers development certainty for residential care facilities serving seven or more and large residential care facilities consistent with State law. persons in all residential zones. This program is being continued in compliance with recent changes to State density bonus law. City staff discusses opportunities for affordable housing and density bonuses with developers for housing projects. As mentioned above, an inclusionary housing requirement is also being considered for the TCSP, in addition to other incentives to increase density. The density bonus program is Amend the Development Code in 2021 consistent with current Density Bonus among several tools the City utilizes to facilitate affordable housing. On July 16, 12. Affordable Housing Incentives/ Density Law and continue to encourage the production of affordable housing through 2024, the City adopted a Development Code Amendment to be in conformance Bonus the use of density bonus and other incentives. with current Density Bonus Law. The City is also a member of the San Gabriel Valley Regional Housing Trust (SGVRHT), which is a joint powers authority. SGVRHT's focus is primarily on providing fundings assistance in the planning and construction of new homeless and affordable housing. The Trust provides funding and loans to help bridge funding gaps for affordable housing projects. The City continues to offer efficient permit processing. As a small city, staff is able to work closely with applicants through the review and approval process, thereby helping to expedite the entitlement process to issuance of building and zoning permits. In addition, the City has several procedures in place to minimize project review times, which include concurrent processing, pre -application reviews, and recently adopted General Plan EIR, which allows for individual projects that fall within the scope of the EIR to utilize this as environmental 13. Efficient Project Processing Continue to offer streamlined development processing, and periodically review clearance under CEQA. departmental processing procedures to ensure efficient project processing. Practices to streamline the issuances for residential projects such as room additions and ADUs have been implemented to eliminate the need to submit a separate application for Planning prior to applying for building permits. The pandemic accelerated implementation of online permit services, and by June 2020, applicants were able to submit applications, plans and payments entirely online. In 2023, the City embarked on the implementation of a new permitting software (Enterprise Land Management system), which will eventually streamline City processes and project processing and expected to go live by Page 48 of 50 Page 64 of 328 PROGRAM # OBJECTIVES STATUS July 2026. This program will be further enhanced through revisions to the Development Code. Explore and pursue alternative land use strategies and make necessary On December 21, 2021, the City adopted an urgency ordinance to expand the amendments to zoning and other land use documents to facilitate a variety of housing supply in single-family zones by allowing for lot splits and duplexes housing choices, including but not limited to higher density opportunities on under the parameters of SB 9. The permanent ordinance is anticipated for 14. Affirmatively Furthering Fair Housing religious, institutional and quasi -institutional lands, missing middle zoning in Planning Commission hearing in the Fall of 2026. addition to S139 such as S1310, adaptive reuse, more than one JADU per The City continues to distribute fair housing information at the public counter structure, acquiring and adding affordability to existing structures and upzoning through brochures, and refers fair housing related complaints to the Housing with the goal of 50 housing opportunities in the planning period. Rights Center. The City supports the provision of housing for disabled persons through zoning opportunities for transitional housing, reasonable accommodation procedures, and programs to facilitate affordable housing. In 2010, the City adopted an ordinance to facilitate reasonable accommodations. This program is an important component of the City's overall efforts to address the special housing 15. Reasonable Accommodation for Continue to implement reasonable accommodation procedures for persons with needs of persons with disabilities and is being continued and revised to include Persons with Disabilities disabilities in compliance with SB 520. additional amendments to City regulations to incorporate recent changes to State law. The City is currently processing a Development Code Amendment to ensure that reasonable housing accommodation procedures do not inadvertently act as a constraint on persons with disabilities. The Code Amendment is anticipated for Planning Commission hearing in the Fall of 2026. Page 49 of 50 Page 65 of 328 Climate Action Plan CAP POLICIES AND ACTIONS IMPLEMENTATION GENERAL PLAN GOALS & POLICIES CLIMATE ACTION PLAN ("CAP") A Climate Action Plan is a comprehensive inventory of specific activities a public agency should undertake to reduce greenhouse gas ("GHG") emissions that originate within its jurisdiction. The City of Diamond Bar adopted a Climate Action Plan concurrently with the General Plan Update to document how it will be able to reduce its GHG emissions in compliance with State mandates and goals to the year 2040, which is the horizon year for the General Plan Update. The table below lists the General Plan Update goals and policies that have been implemented to reduce GHG emissions, quantifies emissions reductions, and explains how these policies and actions will be implemented and organized according to the following categories: 1. Pedestrian Improvements and Increased Connectivity; 2. Bikeway System Improvements; 3. Traffic Calming; 4. Electric Vehicle Infrastructure; 5. Parking Facilities and Policies; and 6. Transportation Improvements. LU-P-9: See status above. The General Plan Update includes policies that create more walkable, livable neighborhoods by expanding the multi- LU-P-14: See status above. 1. Pedestrian Improvements and modal transportation system and creating a safe, pedestrian -oriented environment. Providing an improved pedestrian CC-G-5: See status above. CC-P-4: See status above. Increased Connectivity network and increasing connectivity encourages people to walk more and results in people driving less, causing a CC-P-7: See status above. reduction in vehicle miles traveled (VMT). CC-P-9: See status above. CC-P-21: See status above. LU-P-14: See status above. The General Plan Update provides strategies for maximizing multi -modal accessibility to and connectivity within mixed CC-G-5: See status above. 2. Bikeway System Improvements use areas, including the Metrolink Station and new Town Center. With the total bicycle improvements listed in the General CC-P-7: See status above. Plan Update, there would be approximately 2.4 miles of bike lanes per square mile. Diamond Bar currently has CR-G-2: See status above. approximately 2,840 people per square miles. This corresponds to a 0.06 percent reduction in VMT emissions. CR-P-30: See status above. CR-P-43: See status above A 0.25 percent reduction in VMT was assumed to occur from the traffic calming improvements to make streets safer and CR-P-4: See status above. 3. Traffic Calming more comfortable for pedestrian travel. Traffic calming devices include roundabouts, corner bulb -outs, speed cushions, CR-P-21: See status above. surface textures, raised pavement, road narrowing, and other devices that encourage people to drive more slowly or to CR-P-22: See status above. walk or bike instead of using a vehicle, especially for short trips in and around residential neighborhoods. CR-P-23: See status above. A 0.05 percent reduction in VMT was assumed to occur from installation of electric vehicle infrastructure, which will 4. Electric Vehicle Infrastructure encourage Diamond Bar residents, businesses, and the City vehicle fleet to switch to clean fuel and electric vehicles in RC-P-28: See status above. order to reduce energy use and cost and transportation related GHG emissions. Parking policies reflect both the necessity of providing for adequate and appropriately located vehicle and bicycle parking in existing and new development, and priorities related to safety, urban design, and transportation management. Reduced 5. Parking Facilities and Policies parking standards and other policies reducing parking availability have an estimated 5 to 12.5 percent VMT reduction. N/A Conservatively assuming the effect of General Plan parking reduction strategies would result in the lower end of VMT reduction, the cumulative reduction from implementations would result in a 5 percent VMT reduction. Transit service can provide an alternative to automobile travel and is a critical mode of transportation for those who cannot drive or do not have access to a vehicle. The General Plan policies support Metrolink ridership by improving bus, bicycle, CR-G-13: See status above. 6. Transportation Improvements and pedestrian connections to the station and by introducing Transit -Oriented Mixed -Use development around the station. CR-P-48: See status above. Conservatively assuming the combined effect of these strategies, summing the low end of the VMT reduction ranges gives a 0.62 percent reduction in VMT emissions. Page 50 of 50 Page 66 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 PLANNING COMMISSION AGENDA REPORT CASE/FILE NUMBER: Development Code Amendment No. PL2024-51 PROJECT LOCATION: Citywide APPLICATION REQUEST: To amend Title 22 of the Diamond Bar City Code (DBCC), adding Chapter 22.19 to establish multifamily and mixed -use residential Objective Design Standards (ODS) to implement State housing mandates. APPLICANT: Community Development Department SUMMARY: The proposed Development Code Amendment would amend Title 22 of the City's Development Code to establish Citywide objective design standards (ODS), for multifamily and mixed -use residential development projects to implement the City's certified Housing Element and be in compliance with State housing mandates. RECOMMENDATION: Adopt the attached resolution recommending the City Council approve Development Code Amendment No. PL2024-51, amending Title 22 of the Diamond Bar City Code (DBCC), adding Chapter 22.19 to establish multifamily and mixed -use residential ODS. BACKGROUND: Recent State housing legislation, including Senate Bill 35 and Senate Bill 330, established mandates for cities and counties to streamline the review process for multifamily housing, including mixed -use developments. Consequently, local agencies are now required to limit their review of qualifying housing projects to objective standards. ODS will apply to construction projects located anywhere in the City involving the development or substantial improvement to multifamily residential projects including duplexes, townhouses or multifamily dwellings or mixed -use projects featuring a combination of multifamily residential and other uses. ODS will not apply to single-family housing in single-family zones, or to nonresidential projects. The legislation defines "objective standards" as standards that involve no personal or subjective judgment by a public official and are uniformly verifiable by reference to an external and uniform benchmark or criterion. In addition, Program H-8 of Diamond Bar's certified 6th Cycle (2021-2029) Housing Element commits the City to update the Development Code (Title 22 of the Diamond Bar City Code) to include objective standards as part of its broader obligation to minimize constraints on housing supply and affordability. Presently, Diamond Bar reviews housing projects using both objective and non-objective standards established through the Development Code and the Citywide Design Guidelines. To bring Diamond Bar into compliance Page 67 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 with State law, as well as implement its Housing Element programs, the City must proceed with the formulation of solely objective standards to govern the design of the aforementioned residential and mixed -use project types. The standards will then be utilized by staff and the Planning Commission as the basis to approve or deny such projects. The absence of ODS would compel the City to limit its review of these project types to only the most basic development standards currently in place, such as setbacks, height and parking requirements; architectural style and form -based criteria such as bulk, mass, scale and neighborhood compatibility would be beyond the City's authority to regulate design, and can no longer be the basis for denying a project until a comprehensive ODS ordinance is adopted. In 2024, the City retained Torti Gallas + Partners (TG+P) to develop ODS under an amendment to the Consultant Services Agreement for the Town Center Specific Plan. Staff held a kickoff meeting and toured the City with TG+P on July 24, 2024. The project team collected data, reviewed background documents such as existing design standards and guidelines, as well as ODS from other cities as the basis for expressing desired qualitative outcomes through the application of objective standards. Prior to preparing the draft standards, the City conducted a joint study session with the City Council and Planning Commission on October 8, 2024. The purpose of the study session was to introduce the ODS project, explain the process, and invite feedback and direction to guide the preparation of the draft ODS. Key discussion points were considered and incorporated into the draft ODS, such as restricting Contemporary architecture adjacent to existing single-family residential neighborhoods. Following the meeting, the project team proceeded with preparation of the ODS, which included core tasks defining various types of multifamily and mixed -use buildings and identifying their associated design elements. The tasks included: • Research of existing architectural styles in the City. • Identified stakeholder groups and conducted meetings to gather feedback. • Defined various building types, frontage types, and style options. • Creation of a user-friendly document showcasing these design options. ANALYSIS: The proposed Development Code Amendment would amend Title 22 of the City's Development Code to establish objective design standards. If adopted, the ordinance would add DBCC Chapter 22.19 and incorporate by reference a new document entitled Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development, provided as Exhibit 1 to the draft ordinance (Attachment 1). The document is organized into seven chapters: 1. Introduction 2. Building Type Standards 3. Building Articulation Standards 4. Frontage Types 5. Site and Open Space Standards 6. Architectural Styles 7. Glossary Below is a summary of these chapters: Chapter 1 - Introduction This chapter provides an introduction to the ODS which includes the following: purpose and intent, goals, design principles, applicability, how to use the document, and relationship with the General Plan and Development Code. The Development Code will continue to govern basic development standards, while the ODS will further refine specific standards related to architectural styles and building design. Chapter 2 - Building Type Standards Page 68 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 To support a variety of household types, the ODS provides a broad range of building type options for multifamily and mixed -use residential development including: townhouses, flex/lofts, walkups, courtyard buildings, urban block structures, and wrap buildings. Once a specific building type is selected, the development must comply with the associated standards, including maximum fapade width, pedestrian access, parking, common open space, landscaping, frontage types, and overall massing. 45' MAX Flex/Loft Building Diagram Example Chapter 3 - Building Articulation Standards In order to preserve the City's character, new development shall be designed to avoid a monolithic appearance. This Chapter establishes standards that require larger projects be articulated as coordinated groupings of smaller structures that, together with a well -designed streetscape, support the City's vision for high -quality development. Some techniques to achieve this include horizontal and vertical articulation, architectural projections and recessions, facade differentiation, architectural style differentiation and base - middle -top articulation. Articulation refers to the deliberate arrangement and detailing of a building's elements to express its structure and spatial functions meaningfully. It involves creating visual connections between different parts of a design —for example, using columns, ledges, or level changes to define spaces or employing varied textures, colors, and materials on a facade to enhance visual interest. Architectural Style Differentiation Diagram Example Chapter 4 - Frontage Types A building's frontage serves as the interface between the public realm and private development. Thoughtful design of this interface is essential to creating an active and engaging urban environment. Multifamily and mixed -use buildings should feature ground -floor frontages that are human -scaled, visually interesting, and provide direct access to ground -floor uses. This chapter presents a range of prototypical frontage types, along Page 69 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 with associated standards for dimensional requirements, openings, and ground -plane features such as furnishing zones, paving and landscaping. Raised Commercial Terrace Illustrative Photo Chapter 5 - Site and Open Space Standards This chapter establishes standards addressing the functional aspects of buildings and the detailed design of outdoor spaces. Notable provisions include requirements for outdoor seating areas and furnishings to be constructed of specified materials, landscaping to incorporate tiered designs, and retaining walls to be decorative when visible from the street. The goal of this chapter is to ensure that outdoor space design supports and enhances the creation of a human -scaled, urban environment. Tall Tier: 3'-0" to 4'-0" High Foundation and Flowering Shrubs Mid -Level Tier: 2'-0" to 2'-8" High Flowering and Annual Shrubs Low Tier: 1'-6" to 2'-6" High Perennials and Groundcover Parkway: Less than 24" High Foot traffic tolerant Low Perennials and Groundcover Tiered Planting Illustrative Example Chapter 6 - Architectural Styles Multifamily and mixed -use residential development shall conform to one architectural style and one corresponding building type for each proposed building. This chapter identifies five architectural styles that may be utilized for adherence to the ODS: Main Street Commercial, Spanish Revival, Craftsman, Art Deco, and California Contemporary. These styles were selected because variations of them are among the most prominent throughout the San Gabriel Valley. Each style is described to help users understand its historical context and to guide the preparation of contemporary designs that reflect these traditional styles. Page 70 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 Spanish Revival Illustrative Photo Example Chapter 7 - Glossar This chapter provides definitions of terms and phrases used throughout the ODS that are technical or that may not reflect common usage, and is intended to supplement the Development Code definitions (DBCC Chapter 22.80). If a definition in the OSD conflicts with a definition in the Development Code, the ODS definitions shall control for the purposes of new developments. If a word or phrase used in the ODS is not defined in the ODS or in the Development Code, the Director shall make a determination, giving deference to common usage and the context in which the term or phrase is used. Citv Attornev Review The City Attorney's Office identified necessary edits to the draft ODS to ensure all standards are truly objective, which have been incorporated into the final version. NOTICE OF PUBLIC HEARING: Notice for this hearing was published in the San Gabriel Valley Tribune newspaper on February 4, 2026, in a 1 /8- page display. Pursuant to Planning and Zoning Law Government Code Section 65091 (a)(4), if the number of property owners to whom a public hearing notice would be mailed is greater than 1,000, a local agency may provide notice by placing a display advertisement of at least 1 /8 page in one newspaper of general circulation. A copy of the public notice was also posted at the City's designated community posting sites. PUBLIC COMMENTS RECEIVED: No comments have been received as of the publication date of this report. ENVIRONMENTAL ASSESSMENT: On December 17, 2019, the Diamond Bar City Council certified Final EIR (No. SCH 2O18051066) for the Diamond Bar 2040 General Plan and Climate Action Plan. In 2022, the City adopted the 2021-2029 Housing Element Update and concurrently amended the General Plan 2040 Land Use and Economic Development Element. The potential impacts of the 2021-2029 Housing Element Update and concurrent Land Use and Economic Development Element amendment were determined to be within the scope of the Certified EIR. The City concluded that neither a subsequent nor a supplemental EIR was required. Accordingly, the City adopted Addendum No. 1 to the Certified EIR on August 11, 2022. Page 71 of 328 Agenda Item #: 6.1 Meeting Date: February 24, 2026 The draft ODS anticipates residential and mixed -use development consistent with the assumptions in the 2040 General Plan and analyzed in the General Plan EIR. CEQA Guidelines Section 15164(a) states: "The lead agency or responsible agency shall prepare an addendum to a previously certified EIR if some changes or additions are necessary but none of the conditions described in Section 15162 calling for preparation of a subsequent EIR have occurred." Pursuant to CEQA Guidelines Section 15164, the City has prepared Addendum No. 2 to the General Plan EIR (Attachment 2), which demonstrates that adoption of the ODS would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts analyzed in the Certified EIR for the City General Plan 2040. In addition, the information throughout the addendum affirms that there is no new information of substantial importance that was previously unknown and is now available. Therefore, a subsequent EIR would not be required pursuant to Section 15162 of the State CEQA Guidelines. The City has thus determined an addendum to the previously Certified EIR to be the appropriate environmental compliance document for the proposed project. PREPARED BY: Mayuko Nakajima, Senior Planner, Community Development ATTACHMENTS: Draft Planning Commission Resolution No. 2026-XX (Recommending Approval of Development Code Amendment) Addendum No. 2 to the Diamond Bar Comprehensive General Plan Update and Climate Action Plan Environmental Impact Report Page 72 of 328 PLANNING COMMISSION RESOLUTION NO. 2026-XX A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF DIAMOND BAR RECOMMENDING TO THE CITY COUNCIL APPROVAL OF PROPOSED AMENDMENTS TO TITLE 22 OF THE DIAMOND BAR MUNICIPAL CODE ("DEVELOPMENT CODE"), ADDING CHAPTER22.19 TO ESTABLISH MULTIFAMILY AND MIXED -USE RESIDENTIAL OBJECTIVE DESIGN STANDARDS ("ODS") IN ACCORDANCE WITH STATE HOUSING MANDATES - PLANNING CASE NO. PL2024-51. A. RECITALS 1. Title 22 (Development Code) of the Diamond Bar City Code (DBCC) establishes allowable uses of property and related development standards within all zoning districts in the City; 2. Several provisions of State law, including, but not limited to, Senate Bill 35 and Senate Bill 330, established mandates for cities and counties to streamline the review process for multifamily housing, including mixed -use residential developments and require local agencies are required to limit their review of qualifying housing projects to objective standards; 3. Implementation of Program H-8 of Diamond Bar's certified 6th Cycle (2021-2029) Housing Element commits the City to update the Development Code to include objective standards as part of its broader obligation to minimize constraints on housing supply and affordability; 4. The City desires to establish ODS applicable to multifamily housing and mixed -use residential development projects in the City in order to implement the Housing Element and to appropriately regulate development in a manner consistent with State law and which facilitates a fair and efficient review process that results in high quality development and buildings that are appropriate for their context and environment; 5. This Project has been reviewed for compliance with the California Environmental Quality Act (CEQA). Pursuant to CEQA Guidelines Section 15164, the City has prepared Addendum No. 2 to the General Plan EIR (No. SCH 2O18051066), which demonstrates that adoption of the ODS would not result in new or substantially more severe impacts beyond those that were evaluated in the EIR for the City General Plan 2040; therefore, no subsequent environmental document is required; 6. Pursuant to Government Code Sections 65090, a notice of at least 1/8 page display was published in the San Gabriel Valley Tribune newspaper on February 4, 2026, and a copy of the public notice was posted at the City's designated community posting sites; 7. On February 24, 2026, the Planning Commission held a duly noticed public hearing regarding the proposed Development Code Amendment reflected in the draft ordinance attached hereto as Exhibit "A" and incorporated by reference into this Resolution, and duly considered all public testimony, evidence, and staff analysis; and 8. All legal prerequisites to the adoption of this Resolution have occurred. Page 73 of 328 B. RESOLUTION NOW, THEREFORE, it is found, determined and resolved by the Planning Commission of the City of Diamond Bar as follows: 1. This Planning Commission hereby specifically finds that all of the facts set forth in the Recitals, Part A, of this Resolution are true and correct. 2. Based on the findings and conclusions set forth above, the Planning Commission hereby recommends that the City Council approve Development Code Amendment No. PL2024-51 by adopting amendments to Title 22 of the Diamond Bar Municipal Code described in the draft ordinance attached hereto as Exhibit "A" and incorporated herein by reference. The Planning Commission Secretary shall: (a) Certify to the adoption of this Resolution; and (b) Forthwith transmit a certified copy of this Resolution to the City Council of the City of Diamond Bar. APPROVED AND ADOPTED THIS 24TH DAY OF FEBRUARY, 2026, BY THE PLANNING COMMISSION OF THE CITY OF DIAMOND BAR. , Chairperson I, Greg Gubman, Planning Commission Secretary, do hereby certify that the foregoing Resolution was duly introduced, passed, and adopted, at a regular meeting of the Planning Commission held on the 24th day of February, 2026, by the following vote: AYES: Commissioners: NOES: Commissioners: ABSENT: Commissioners: ABSTAIN: Commissioners: ATTEST: Greg Gubman, Secretary Page 74 of 328 Exhibit A ORDINANCE NO. XX (2026) AN ORDINANCE OF THE CITY OF DIAMOND BAR AMENDING TITLE 22 OF THE DIAMOND BAR MUNICIPAL CODE ("DEVELOPMENT CODE"), ADDING CHAPTER 22.19 TO ESTABLISH MULTIFAMILY AND MIXED -USE RESIDENTIAL OBJECTIVE DESIGN STANDARDS ("ODS") IN ACCORDANCE WITH STATE HOUSING LAW - PLANNING CASE NO. PL2024-51. WHEREAS, Title 22 (Development Code) of the Diamond Bar City Code (DBCC) establishes allowable uses of property and related development standards within all zoning districts in the City; and WHEREAS, several provisions of State law, including, but not limited to, Senate Bill 35 and Senate Bill 330, established mandates for cities and counties to streamline the review process for multifamily housing, including mixed -use residential developments, and require local agencies to limit their review of qualifying housing projects to objective standards; and WHEREAS, implementation of Program H-8 of Diamond Bar's certified 6th Cycle (2021-2029) Housing Element commits the City to update the Development Code to include objective standards as part of its broader obligation to minimize constraints on housing supply and affordability; and WHEREAS, the City desires to establish ODS applicable to multifamily housing and mixed -use residential development projects in the City in order to implement the Housing Element and to appropriately regulate development in a manner consistent with State law and which facilitates a fair and efficient review process that results in high quality development and buildings that are appropriate for their context and environment; and WHEREAS, on February 24, 2026, the Planning Commission held a duly noticed public hearing regarding proposed amendments to Title 22 ("Development Code") of the Diamond Bar City Code, Planning Case No. PL2024-51, and adopted Resolution No. 2026-_ recommending City Council approval of said Development Code Amendment; and WHEREAS, pursuant to Government Code Section 65090, a notice of at least 1/8 page display was published in the San Gabriel Valley Tribune newspaper on 2026, and a copy of the public notice was posted at the City's designated community posting sites; and WHEREAS, on , 2026, the City Council held a duly noticed public hearing regarding the proposed Development Code Amendment; and WHEREAS, the City Council finds that this Ordinance is subject to the California Environmental Quality Act ("CEQA"). Pursuant to CEQA Guidelines Section 15164, the City has prepared Addendum No. 2 to the General Plan EIR (No. SCH 2O18051066), Page 75 of 328 Ordinance No. (2026) which demonstrates that adoption of the ODS would not result in new or substantially more severe impacts beyond those that were evaluated in the EIR for the City General Plan 2040; therefore, no subsequent environmental document is required; and WHEREAS, the documents and materials constituting the administrative record of the proceedings upon which the City's decision is based are located at the City of Diamond Bar, Community Development Department, Planning Division, 21810 Copley Drive, Diamond Bar, CA 91765; and WHEREAS, the City Council hereby adopts the facts and reasons stated in Planning Commission Resolution No. 2026-_ recommending City Council approval of the said Development Code Amendments, a copy of which is on file with the City Clerk and which is incorporated herein by reference with the same force and effect as if set forth in full. NOW, THEREFORE, the City Council of the City of Diamond Bar does hereby find, determine and ordains as follows: SECTION 1: Chapter 22.19 (Objective Design Standards for Multifamily and Mixed -Use Development) of Title 22 of the Diamond Bar City Code is hereby added as follows: Sec. 22.19.010. — Purpose. The purpose of this chapter is to establish citywide objective design standards (ODS) to ensure consistent, transparent, and measurable review of multifamily and mixed -use residential development projects in accordance with State law. The ODS is intended to streamline project approvals by providing clear verifiable criteria for design that do not require subjective interpretation. Sec. 22.19.020. — Applicability. The objective design standards will apply to construction projects located anywhere in the City involving the development or substantial improvement of any of the following: Multifamily residential projects, including duplexes, townhouses, or multifamily dwellings. 2. Mixed -use projects featuring a combination of multifamily residential or other uses. All such development shall be subject to the Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development, which is on file with the City Clerk, and which is incorporated by reference into this Section 22.19.020 as if fully set forth herein. SECTION 2: Subsection (m) of Section 22.80.020 (Definitions of specialized terms and phrases) of Title 22, Chapter 22.80 of the Diamond Bar City Code 061 Page 76 of 328 Ordinance No. (2026) is amended to add a new definition for "mixed -use" as follows: (m) Definitions, W." The following definitions are in alphabetical order - Mixed -use. The combination of nonresidential and residential uses located on the same property as part of a unified development. Mixed -use development may consist of commercial and residential uses integrated either vertically (vertical mixed -use) in the same structure or group of structures, or horizontally on the same development site (horizontal mixed -use) where parking, open spaces, and other development features are shared. In a residential/commercial mixed -use development, both uses are considered primary uses of the land. SECTION 3: The City Council hereby adopts the Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development, incorporated by reference in DBCC Chapter 22.19 (Objective Design Standards for Multifamily and Mixed -Use Development) and attached to this Ordinance as Exhibit 1. The City Council further directs the City Clerk to maintain a copy of said manual on file in Office of the City Clerk, make it freely accessible to the public, and to cause a copy of the manual to be posted on the official City of Diamond Bar website. SECTION 4: If any section, subdivision, paragraph, sentence, clause or phrase of this Ordinance is for any reason held to be invalid or unconstitutional, such decision shall not affect the validity of the remaining portions of this Ordinance. The City Council hereby declares that it would have passed this Ordinance, and each section, subdivision, paragraph, sentence, clause and phrase thereof, irrespective of the fact that any one (or more) section, subdivision, paragraph, sentence, clause or phrase had been declared invalid or unconstitutional. SECTION 5: The City Clerk shall attest and certify to the passage and adoption of this Ordinance within 15 days after adoption, cause it to be published or posted in accordance with California law, and it shall be effective 30 days after adoption pursuant to Government Code Section 36937. 3 Page 77 of 328 Ordinance No. (2026) APPROVED AND ADOPTED THIS TH DAY OF , 2026, BY THE CITY COUNCIL OF THE CITY OF DIAMOND BAR. Steve Tye, Mayor I, Kristina Santana, City Clerk of the City of Diamond Bar, do hereby certify that the foregoing Ordinance was duly introduced at a regular meeting of the City Council of the City of Diamond Bar held on the _th day of , 2026, and was finally passed at a regular meeting of the City Council of the City of Diamond Bar held on the _th day of 2026, by the following vote: AYES: NOES: ABSENT: ABSTAIN ATTEST: Councilmembers: Councilmembers: Councilmembers: Councilmembers: Kristina Santana, City Clerk E Page 78 of 328 or Fter' I A M tO-,.l OBJI DESIGN L 1%0 Nlk I - 17 ■ Rim * MEM AMEN" -4� qW RDS FOR MULTIFAMILY & MIXED -USE DEVELOPMENT ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS CITY OF DIAMOND BAR CITY COUNCIL Steve Tye, Mayor Ruth M. Low, Mayor Pro Tern Andrew Chou, Council Member Stan Liu, Council Member Chia Yu Teng, Council Member PLANNING COMMISSION Brian Worthington, Vice Chairperson Bill Rawlings, Commissioner Ruben Torres, Commissioner Surendra Mehta, Commissioner Lee Mao, Commissioner Naila Barlas, Former Commissioner LEGAL COUNSEL Omar Sandoval James H. Eggart Ricia R. Hager Dan Cruz CITY STAFF Daniel Fox, City Manager Greg Gubman, Community Development Director Grace S. Lee, Planning Manager Mayuko Nakajima, Senior Planner Rudy Lopez, Assistant Planner Arlene Laviera, Administrative Coordinator i Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ACKNOWLEDGEMENTS CONSULTANT TEAM TORTI GALLAS + PARTNERS, INC Master Planning and Urban Design Neal I. Payton, FAIA, FCNU, Principle -in -charge Rogelio Huerta Betina Sason SAPPHOS ENVIRONMENTAL, INC Environmental Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ii TABLE OF CONTENTS TABLE OF CONTENTS 1.Introduction...........................................1 1.1 Purpose and Intent .............................2 1.2 Goals.......................................3 1.3 Design Principles .............................. 4 1.4 Applicability ................................. 5 1.5 How to Use This Document .......................7 1.6 Relationship with General Plan and Development Code . 9 2. Building Type Standards ................................ 11 2.1 Introduction ................................. 12 2.2 Explanation of Standards ....................... 13 2.3 Allowable Building Types........................16 2.3.1 Duplex, Triplex, Fourplex .................... 17 2.3.2 Townhouse..............................19 2.3.3 Flex/Loft Building ......................... 21 2.3.4 Auto Court or Six/Eight Pack ................23 2.3.5 Walk -Up Flats ............................25 2.3.6 Carriage House ...........................27 2.3.7 Small Mixed -Use Building ...................29 2.3.8 Courtyard Multi -Family Building .............. 31 2.3.9 Wrap Building ............................33 2.3.10 Urban Block .............................35 2.3.11 Mixed -Use Big Box ........................37 3. Building Articulation Standards ......................... 39 3.1 Purpose ................................... 40 3.2 Building Articulation Techniques ................. 42 3.3 Transition to Single -Family Residential Districts..... 46 3.4 Entrances .................................. 46 3.5 Passageways.................................47 3.6 Windows....................................47 3.7 Roof Standards...............................47 3.8 Encroachments and Projections ................. 48 3.9 Shopfronts in Mixed -Use Buildings ............... 50 3.10 Colors and Materials .......................... 51 4.Frontage Types......................................53 4.1 Purpose and Intent .......................... 54 4.2 Explanation of Standards ...................... 55 4.3 Shopfronts in Mixed -Use Buildings ................57 4.4 Raised Commercial Terrace in Mixed -Use Buildings... 58 iii Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development TABLE OF CONTENTS 4.5 Stoop ..................................... 59 4.6 Dooryard................................... 60 4.7 Front Porch .................................. 61 4.8 Forecourt .................................. 62 4.9 Raised Residential Terrace ..................... 63 4.10 Urban Frontage ............................. 64 5. Site and Open Space Standards ......................... 65 5.1 Purpose and Intent .......................... 66 5.2 Grading Standards ............................67 5.3 Outdoor Seating Areas, Cafes and Restaurants in Mixed -Use Zones ................................ 68 5.4 Outdoor Furnishings Visible from ROWS Applicable to Mixed -Use Zones ................................ 68 5.5 Landscape Standards ......................... 69 5.6 Common Open Space ...........................70 5.7 Interior Courtyards ............................70 5.8 Fences, Hedges and Walls ....................... 71 5.9 Retaining Walls ............................... 71 5.10 Vehicular Parking ............................72 5.11 Loading Areas...............................72 5.12 Bicycle Parking Standards ......................72 5.13 Service and Auxiliary Equipment .................73 5.14 Exterior Lighting .............................73 6. Architectural Styles .................................. 75 6.1 Intent.....................................76 6.2 Main Street Commercial ........................77 6.3 Spanish Revival .............................. 83 6.4 Craftsman...................................87 6.5 Art Deco . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 6.6 California Contemporary ........................97 7. Glossary of Terms ................................... 103 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development iv FIGURES FIGURES 2. Building Type Standards 2-1 Key Building Type Elements ..........................14 2-2 Maximum Footprint per Story Diagram ................. 15 2-3 Common Open Space Diagram ........................15 2-4 Duplex, Triplex, Fourplex Diagram .................... 17 2-5 Duplex, Triplex, Fourplex Illustrative Photo .............18 2-6 Townhouse Diagram...............................19 2-7 Illustration of a Townhouse Stacked over a Separate Flat ...................................... 20 2-8 Townhouse Illustrative Photo ....................... 20 2-9 Section of a Townhouse ........................... 20 2-10 Section of a Townhouse Wrapping the Podium of Garage ......................................... 20 2-11 Section of a Townhouse on a Sloping Site ............. 20 2-12 Section of a Townhouse Not Permitted ............... 20 2-13 Flex/Loft Building Diagram ......................... 21 2-14 Flex/Loft Building Illustrative Photo ..................22 2-15 Auto Court or Six/Eight Pack Diagram.................23 2-16 Auto Court or Six/Eight Packt Illustrative Photo . . . . . . . . . 24 2-17 Auto Court or Six/Eight Pack Illustrative Photo .........24 2-18 Walk -Up Flats Diagram ............................25 2-19 Walk -Up Flats Illustrative Photo .....................26 2-20 Carriage House Diagram ...........................27 2-21 Concept Rendering of Carriage House .................28 2-22 Carriage House Illustrative Photo....................28 2-23 Small Mixed -Use Building Diagram ...................29 2-24 Small Mixed -Use Building Diagram .................. 30 2-25 Small Mixed -Use Building Illustrative Photo ........... 30 2-26 Courtyard Multifamily Building Diagram ............... 31 2-27 Courtyard Building Illustrative Photo .................32 2-28 Wrap Building Diagram ............................33 2-29 Wrap Building Illustrative Photo ................... 34 2-30 Urban Block Diagram .............................35 2-31 Urban Block Illustrative Photo.......................36 2-32 Urban Block Illustrative Photo ......................36 2-33 Mixed -Use Big Box Diagram .........................37 2-34 Mixed -Use Big Box Illustrative Photo ................ 38 2-35 Mixed -Use Big Box Illustrative Photo ................ 38 3. Building Articulation Standards 3-1 Multiple Variations of Same Style ................... 42 v Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FIGURES 3-2 Mixed -Use Building Articulated with Corner ............ 42 3-3 Horizontal Articulation Diagram .................... 43 3-4 Vertical Articulation Diagram ....................... 43 3-5 Architectural Projections Diagram .................. 43 3-6 Architectural Recessions Diagram ................... 44 3-7 Facade Differentiation Diagram ..................... 44 3-8 Architectural Style Differentiation Diagram ............ 44 3-9 Base, Middle, and Top Articulation Diagram ............ 45 3-10 Illustrative Diagram ............................. 46 3-11 Entrances ...................................... 46 3-12 Windows.......................................47 3-13 Variety of Rooflines Illustrative Photo ................47 3-14 Encroaching Habitable Space ...................... 48 3-15 Projecting Canopies ............................. 49 3-16 Encroachment and Projections Diagram .............. 49 3-17 Illustrative Photo of Shopfronts in Mixed -Use Buildings .. 50 3-18 Minimum Frontage Glazing Diagram ................. 50 3-19 Changes of Colors and Materials Illustrative Photo ....... 51 4. Frontage Types 4-1 Shopfronts in Mixed -Use Buildings Illustrative Photo ......57 4-2 Shopfronts in Mixed -Use Buildings Conceptual Plan ......57 4-3 Shopfronts in Mixed -Use Buildings Illustrative Section . . . . . 57 4-4 Raised Commercial Terrace Illustrative Photo .......... 58 4-5 Raised Commercial Terrace Conceptual Plan ........... 58 4-6 Raised Commercial Terrace Illustrative Section ......... 58 4-7 Stoop Illustrative Photo ........................... 59 4-8 Stoop Conceptual Plan ............................ 59 4-9 Stoop Illustrative Section ......................... 59 4-10 Dooryard Illustrative Photo ........................ 60 4-11 Dooryard Conceptual Plan ......................... 60 4-12 Dooryard Illustrative Section ...................... 60 4-13 Front Porch Illustrative Photo ....................... 61 4-14 Front Porch Conceptual Plan........................61 4-15 Front Porch Illustrative Section ..................... 61 4-16 Forecourt Illustrative Photo ....................... 62 4-17 Forecourt Conceptual Plan ........................ 62 4-18 Forecourt Illustrative Section ...................... 62 4-19 Raised Residential Terrace Illustrative Photo .......... 63 4-20 Raised Residential Conceptual Plan ................. 63 4-21 Raised Residential Terrace Illustrative Section ......... 63 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development vi FIGURES 4-22 Urban Frontage Illustrative Photo ................... 64 4-23 Urban Frontage Conceptual Plan .................... 64 4-24 Urban Frontage Illustrative Section ................. 64 5. Site and Open Space Standards 5-1 Illustrative Photo of Terrace Frontage..................67 5-2 Illustrative Photo Showing Outdoor Seating Areas, Cafes and Restaurants in Mixed -Use Conditions .................... 68 5-3 Illustrative Photo Showing Street Furnishings in Mixed -Use Conditions ........................................ 68 5-4A Two Tiers of Planting ............................ 69 5-4B Three Tiers of Planting .......................... 69 5-5 Common Open Space Illustrative Photo ................70 5-6 Interior Courtyard Illustrative Photo ..................70 5-7 Hedge Screening Service Area ....................... 71 5-8 Service and Auxiliary Equipment Illustrative Photo .......73 6. Architectural Styles 6-1 Main Street Commercial Illustrative Photo ..............77 6-2 Main Street Commercial Illustrative Photo ..............77 6-3 Rectangular Form Percentage Diagram.................78 6-4 Large Windows Ground Floor ........................78 6-5 Decorative Brick..................................78 6-6 Single Plane.....................................78 6-7 Cornice.........................................78 6-8 Parapet and Cornice...............................78 6-9 Awnings at Commercial Frontage .....................79 6-10 Canopy Frontage.................................79 6-11 Roof with Detailed Parapet .........................79 6-12 Main Street Commercial Elements Diagram (Ground Floor Commercial) ............................ 80 6-13 Main Street Commercial Elements Diagram (Ground Floor Residential) ............................. 81 6-14 Spanish Revival Illustrative Photo ................... 83 6-15 Spanish Revival Illustrative Photo ................... 83 6-16 Volumetric Composition Diagram ................... 84 6-17 Painted Base with Recess ......................... 84 6-18 Single Plane Composition ......................... 84 6-19 Balcony Overextending Sidewalk .................... 84 6-20 Parapet with Flat Roof .......................... 84 6-21 Clay Tile with No Eave ............................ 84 6-22 Spanish Revival Elements Diagram .................. 86 vii Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FIGURES 6-23 Craftsman Illustrative Photo........................87 6-24 Craftsman Illustrative Photo........................87 6-25 Masonry and Stone Base .......................... 88 6-26 Gutter and Downspout ........................... 88 6-27 Paired Openings Composed Horizontally .............. 88 6-28 Painted Shingles Over Siding ...................... 88 6-29 Space Betweem Columns and Piers .................. 88 6-30 Craftsman Illustrative Photo ...................... 88 6-31 Craftsman Illustrative Photo ....................... 89 6-32 Bracketing of a Roof Gable ........................ 89 6-33 Craftsman Elements Diagram ...................... 90 6-34 Art Deco Illustrative Photo .........................91 6-35 Art Deco Illustrative Photo .........................91 6-36 Art Deco Illustrative Photo .........................92 6-37 Ground Floor as Base .............................92 6-38 Art Deco Illustrative Photo .........................92 6-39 Art Deco Illustrative Photo .........................92 6-40 Extensions with Metal Panels.......................92 6-41 Undulating Parapet...............................92 6-42 Stepped -Back Volumes ............................93 6-43 Art Deco Illustrative Photo .........................93 6-44 Art Deco Elements Diagram (Ground Floor Commercial).. 94 6-45 Art Deco Elements Diagram (Ground Floor Residential) .. 95 6-46 California Contemporary Illustrative Photo ............97 6-47 California Contemporary Illustrative Photo ............97 6-48 Example of a Base Articulated as Glass Panels ........ 98 6-49 Example of California Contemporary Townhouse ....... 98 6-50 California Contemporary Illustrative Photo ........... 98 6-51 Different Materials Identify Different Fagade Planes..... 98 6-52 Roof Articulated with Projected Metal Overhang Serving as a Cornice ................................. 98 6-53 California Contemporary Illustrative Photo ........... 98 6-54 California Contemporary Illustrative Photo ........... 99 6-55 California Contemporary Elements Diagram (Ground Floor Commercial) ............................100 6-56 California Contemporary Elements Diagram (Ground Floor Residential) ............................ 101 7. Glossary of Terms 7-1 Isometric View of a Podium .........................109 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development viii TABLES TABLES 1. Introduction 1-1 ODS Consistency Criteria ............................ 6 1-2 Step by Step Selection of Applicable Standards .......... 8 2. Building Type Standards 2-1 Building Type Matrix...............................16 2-2 Height in Stories for Courtyard Multifamily Building ...... 31 2-3 Height in Stories for Wrap Building....................33 2-4 Height in Stories for Urban Block.....................35 2-5 Height in Stories for Mixed -Use Big Box ................37 3. Building Articulation Standards 3-1 Building Articulation Standards Matrix ................ 42 4. Frontage Types 4-1 Frontage Type Matrix ............................. 56 ix Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development INTRODUCTION o PURPOSE AND INTENT INTRODUCTION 1.1 Purpose and Intent The Objective Design Standards (ODS) that follow are applicable to proposals for multifamily housing or mixed - use development in the City of Diamond Bar. They are not applicable to projects without multifamily housing. Their purpose is to set the minimum design standards required to assure that new development contributes to a "sense of place." All projects will be evaluated and based on their adherence to the ODS through a Development Review process that includes a mandatory checklist of applicable ODS. The images in this document are for Illustrative purposes, only provided to illustrate intent. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development INTRODUCTION • GOALS 1.2 Goals The Goals of these ODS are as follows: Goal 1: Comply with state mandates to implement new Objective Design Standards for eligible multifamily housing and mixed -use development projects. Goal 2: Ensure that appropriate Objective Design Standards are in place for housing development projects eligible for streamlined ministerial review pursuant to California Government Code Section 65913.4 and other State laws. Goal 3: Ensure building placement and Frontage along existing or proposed streets reflects the intended character. Goal 4: Establish architectural standards for larger buildings to mitigate overall mass and ensure visual interest from all public vantage points. Goal 5: Create human -scaled development that contributes to pedestrian -oriented streets and boulevards in mixed -use zoning districts. Goal 6: Provide design details and illustrations that are prescriptive and objective. 3 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development INTRODUCTION • DESIGN PRINCIPLES 1.3 Design Principles Principle 1: Maintain —and in some cases, elevate —architectural variety, integrity, and quality. Principle 2: Ensure that streets and spaces with high volumes of pedestrian traffic are comfortable, protected from the sun, and visually and physically engaging at the ground level. Principle 3: Create architectural variation along a Block Front through diversity of massing, articulation, and architectural detailing. Principle 4: Animate building edges on the ground floor to create an inviting Public Realm and pedestrian friendly environment and to support multi -modal development and mobility. Principle 5: Orient building Fagades to frame the streets and other Public Spaces and to take advantage of natural features such as sunset, sunrise, mountain views and the like. Principle 6: Provide graceful transitions between larger -scale format of multifamily structures and adjacent smaller scale single-family housing. Principle 7: Provide standards such that new buildings can sit comfortably adjacent to existing buildings of varied styles. Principle 8: Provide off-street parking in surface lots or garages at the rear of buildings so that parking does not dominate the built environment. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 4 INTRODUCTION • APPLICABILITY 1.4 Applicability Title 22 of the Diamond Bar City Code (DBCC) ("Development Code") establishes a Development Review process for new multifamily housing when a proposed project is determined to be consistent with the City's General Plan, applicable Specific Plan or Zoning District regulations, and conforms with the City's Objective Design Standards. These Objective Design Standards will apply to construction projects located anywhere in the City involving the development or substantial improvement of any of the following: 1. Multifamily residential projects, including duplexes, townhouses, or multifamily dwellings. 2.Mixed-use projects featuring a combination of multifamily residential and other uses. 1.4.1 Substantial Improvement Objective Design Standards apply to any substantial improvement to existing multifamily or mixed -use development where any extension, repair, reconstruction or other improvement of a property, the cost of which equals or exceeds fifty (50) percent of the fair market value or assessed value of a property either before the improvement started or, if the property has been damaged, before the damage occurred. Any and all building additions to buildings for which these standards are applicable shall match the style and details of the main structure. 1.4.2 Non -Applicability Single-family homes and projects with no residential component are not subject to these standards. 5 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development INTRODUCTION • CHECKLIST FOR STREAMLINED REVIEW Table 1-1: ODS Consistency Criteria Design Principles Consistent Not Consistent Human -Scaled • Orient building Fagades to frame • Buildings are separated from the street Environment streets/Public Spaces to promote a by parking areas (Principle 4 and pedestrian -friendly environment Goal 5; see sections •Lack of windows/entrances along the 2.1-2.12) • Buildings are located at the front of Fagade to provide a conducive walking the lot and face the street environment • Incorporate building entrances and windows along the Fagade Appropriate Use of • Building(s) adheres to the type- • Building(s) do not adhere to the type - Building Types (Goal 4; specific standards/guidelines of the specific standards and do not create a see section 3.1-3.13) following: maximum Fagade Width, human -scaled and pedestrian -oriented pedestrian access, parking, outdoor environment space, landscape, Frontage Types and building massing Architectural Style • Design features and detailing • Design features and detailing are not (Principle 1; see are consistent with the selected representative of the Architectural Style Chapter 7) Architectural Style selected Building Articulation -Create visual interest and break • Fagades are long, blank walls with little and Massing up the overall massing of larger detailing (Principles 3 and 4; buildings see sections 4.1, 4.2 • Little to no horizontal and vertical and 4.4) -Well-articulated and detailed articulation Fagades Appropriate Transitions • Appropriate transitions are • Scale and massing of development with Adjacent Buildings provided between building(s) does not respond to existing context or (Principles 6 and 7; see and adjacent single-family architectural character Section 4.3) neighborhoods Appropriate Frontage • Building Frontages address the land • Building Frontages do not address land Types (Goal 3 and 4; use context and street environment use and street context appropriately 5.1-5.10) appropriately Common and Private • Provides Common Open Space that • Common Open Space is not integrated Open Space (Principles is an amenity for residents into the overall design of the project 2, 5 and 8; Section 6.5 • Private Open Space with a patio • Balconies are not incorporated into area or balconies for residents living residential units on upper floors above the ground floor Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 6 DIAMOND BAR INTRODUCTION • HOW TO USE THIS DOCUMENT 1.5 How to Use This Document This document provides Objective Design Standards (ODS) to ensure consistent, transparent, and measurable review of development projects in accordance with California State law. These standards are intended to streamline project approvals by providing clear, verifiable criteria for design that do not require subjective interpretation. They assume compliance with the underlying zoning except as noted herein. To effectively use this document: 1. Understand the Structure of the Document The standards are organized by design components —such as layout, massing, Fagade Width, entrance locations, open space, and landscaping —tailored to each menu of options. Each section includes: a. Purpose Statement: Explains the design intent. b. Objective Standards: Measurable and enforceable requirements. c. Illustrations (if applicable): Visual examples to clarify standards. d. Capitalized words or phrases are defined in the Glossary. See Chapter 7, 2. Use these Standards During Project Design Project teams should reference these Standards early in the design process. Each applicable standard must be met as written, without need for discretionary interpretation. 3. Select Applicable Building and Frontage Types as well Building Articulation and Massing Standards and Architectural Styles. (See Table 1-2: Step by Step Selection of Applicable Standards) Before using the detailed design standards, applicants must select from a menu of applicable Building Types, Building Articulation and Massing Standards, Frontage Types, and Architectural Styles for their project site. Choosing from the appropriate types ensures that the project is matched with the correct set of standards in the guide. In many cases, zoning regulations, site context, overlay districts or Specific Plans may limit or guide the allowable types. Applicants shall also comply with the Site and Open Space Standards. The selection of standards is described in Table 1-2 as a series of steps. This step-by-step method is offered for clarity only as it is understood that architectural design is not a linear process. 4. Prepare Submittal Materials Accordingly Clearly document how each applicable standard is met using diagrams, plans, elevations, and written justifications. This will speed up the review process and reduce requests for clarification. S. City Review Process City staff will review your project strictly against the objective standards. If all standards are met, the project will be referred to the applicable review authority with a recommendation for approval. 7 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development INTRODUCTION • HOW TO USE THIS DOCUMENT Table 1-2: Step by Step Selection of Applicable Standards Refers to the general massing and configuration of the Determine Applicable structure (e.g., Townhouse, courtyard apartment, Wrap Building Type Chapter 2 building, Podium building). Each type has its own dimensional and design parameters. Refers to the requirements for building articulation and Determine Applicable massing. These requirements ensure that buildings maintain Building Articulation Chapter 3 appropriate scale, provide visual variety, and contribute Standards positively to the character of streets and neighborhoods — without relying on subjective design opinions. Refers to how the building addresses the Public Realm or Determine Applicable street (e.g., Shopfront, porch, Stoop, Forecourt). The selected Frontage Type Chapter 4 Frontage dictates the rules for entries, transparency, Setbacks, Standards and other elements at the street edge. Are applicable to all Building Types and regulate functional aspects of building form such as materials, lighting, service, Check compliance parking and auxiliary spaces, landscape and outdoor space with Site and Open Chapter 5 design. This section is intended to ensure that development is Space Standards consistent with the goal of creating a human -scale mixed- use environment in which each individual building furthers the overall vision. Applicants must choose an Architectural Style from the set of styles allowed. Architectural Style provides a consistent Determine Applicable visual language for detailing, proportions, and materials —and Architectural Style Chapter 6 when defined objectively, it ensures predictable, high -quality Standards outcomes without relying on subjective design review. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 8 INTRODUCTION • RELATIONSHIP WITH GENERAL PLAN AND DEVELOPMENT CODE 1.6 Relationship with General Plan and Development Code This document is incorporated by reference into the Development Code. If any standards, terms or other provisions from these ODS are found to be in conflict with objective standards set forth in other provisions of the Development Code and not specifically called out as superseding those standards, the standards set forth in the Development Code shall govern. A. General Plan The General Plan contains objective standards related to development Density for all land uses in the City. The Objective Design Standards in this document are consistent with the General Plan and dictate the bulk, mass, and design of buildings in a more fine-grained way than the General Plan. B. Zoning The Development Code located in Title 22 of the City Code contain standards that define Floor Area Ratio (FAR) and land use will continue to dictate basic development standards, and these ODS will apply as part of the Development Code, providing refinement in terms of site and building design. C. Other City Code Sections The City also maintains and enforces standards related to stormwater drainage, Roadway and traffic requirements, hillside development, and standards for work within the public right-of-way to install sidewalks, street trees, and lighting. All construction is subject to Title 15 of the City Code which incorporates the California Building Code with local amendments. These standards will continue to apply unless specifically superseded in this document. 9 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 10 BUILDING TYPE STf'IDARDS Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS a INTRODUCTION BUILDING TYPE STANDARDS 2.1 Introduction To support a variety of household types and foster a rich, diverse built environment, these Objective Design Standards promote a broad range of Building Types. Options include Townhouses, flex/lofts, walkups, Courtyard Buildings, urban Block structures, and wrap buildings. Additional standards address mixed -use configurations compatible with these residential types. Once a specific Building Type is selected, the development must conform to its associated standards, including maximum Facade Width, pedestrian access, parking, common open space, landscaping, Frontage Types, and overall massing. These standards are designed to encourage architectural diversity and ensure all buildings contribute to an active Public Realm while providing private outdoor amenities —such as gardens, courtyards, and porches — where appropriate. While there is flexibility in selecting Building Types within each Block or zoning district, only certain types may be appropriate depending on adjacent uses and other constraints. In the absence of a specific plan, applicants in mixed -use zones must submit a site plan that defines Block layouts and identifies at least two Building Types per Block. This requirement does not apply to developments within multifamily zones. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 12 BUILDING TYPE STANDARDS • EXPLANATION OF STANDARDS 2.2 Explanation of Standards This chapter provides standards for the following eleven Building Types. For each Building Type, the standards described below are provided. See Table 2-1 for a summary of Building Types. These standards are intended to avoid monotonous building designs in favor of more varied designs with reduced bulk at the upper stories. The Building Type standards cover the following: A. Intent Statement This statement defines and describes the development intent and typical characteristics for the respective Building Type. B. Applicability This statement explains whether the type is permitted solely in mixed -use zones, or in both mixed -use and multifamily zones. C. Fagade Width Fagade Width standards regulate the maximum width of a building. However, this dimension may be exceeded if one of the following strategies is employed: Strategy 1 The building is designed to appear as two or more buildings, with distinct entries for each Apparent Building, and such that the space between each Apparent Building is at least 20 feet in width. These buildings may be connected above the ground floor via corridor "bridges" that are set back a minimum of 25 feet from the Fagade Plane. Strategy 2 2. Utilize any four of the following techniques: a. Provide a material change for the entire Height of the massing element. b. Provide a change in the overall type, size, spacing, or proportion of windows or Fenestration system or change in sill Heights and head conditions. c. Provide a change in Fagade Composition including roof Heights, and roof types. For example, placing a symmetrical Fagade next to a Fagade with a repetitive bay system that is not symmetrical would comply with this standard. d.Provide a change in building Height by at least 10 feet or one -Story. e. Provide separate and additional primary entries from the street. f. Provide a change in Architectural Style. D. Building Height & Massing Height standards regulate the maximum building Height. Building Height shall be defined pursuant to the Development Code. Some Building Types require horizontal or vertical Plane Breaks or both (see also Figure 2-1). Horizontal Plane Breaks shall not alleviate the minimum Building Frontage Occupancy requirements. Building Fagades facing Build -to Lines shall provide Plane Breaks in a manner such that the overall Building Frontage meets the minimum Building Frontage Occupancy requirements. Plane Breaks are only required at street -facing Fagades. Furthermore, a maximum allowed Footprint per Story is presented for certain Building Types. The maximum allowable Footprint per Story limits the percentage of occupiable space per building Story in relationship to the building's ground - floor Footprint. For example, a four -Story building that limits the maximum allowable Footprint of the fourth Story to 60 percent may satisfy this requirement by providing stepbacks, decks, patios, building articulation, or similar massing strategies that ensure that the fourth Story occupies no more than 60 percent of the building. Balconies shall count toward the maximum allowable Footprint unless there is at least 18 feet of vertical airspace between each balcony deck and floor unit. 13 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • EXPLANATION OF STANDARDS Common Open Space: Each Building Type requires the Lot Area to be occupied by a certain percentage of green space area, which can be accommodated in a variety of ways, for instance through gardens, yards, patios, courtyards, etc. as described on each Building Type page. Maximum Upper Level Building Frontage Occupancy: Some Building Types have limitations on the percentage of the building front that can be occupied above 45 feet in Height. A standard may limit upper levels to 80% of a Frontage, requiring either a break in Frontage or a Setback of the Building Face by a minimum of 8 feet. Maximum Footprint per Story: The floor area of upper stories shall be less than the area of the building Footprint at grade as indicated by the maximum allowed Footprint per Story charts on each Building Type page. Frontage Type: Each building has certain Fagade conditions that are called Frontage Types. Each Frontage interacts differently with the street and therefore is appropriate for different areas and Building Types. Plane Break: The area of the building where the plane of the Fagade varies in depth, represents a Plane Break. (2) is a Horizontal Plane Break. © is a vertical Plane Break. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 14 BUILDING TYPE STANDARDS • EXPLANATION OF STANDARDS E. Maximum Upper -Level Frontage Occupancy Certain Building Types have limitations on the percentage of the Building Frontage that can be occupied above 45 feet in Height, where such heights are permissible. These standards are included in order to provide more variety and visual interest at the upper levels. The upper -level Frontage Occupancy is based on the ground -floor. F. Frontage Types This standard lists which Frontage Types are permitted for each Building Type. G. Pedestrian Access & Entries This standard regulates the location and orientation of building entries. H. Parking Building Type parking standards provide parking design regulations that are specific to each Building Type. I. Common Open Space 1. Each Building Type requires a specific amount of outdoor space to be designated on site. Ground floor Setbacks less than 15 feet in depth shall not count towards fulfilling the outdoor space requirement. 2. Required outdoor space may either be private, only accessible to the occupants, or open to the general public. Outdoor space may be located at grade, atop a Podium or at the rooftop unless the location is restricted by the selected Building Type. Regardless of location, the design of outdoor space shall maximize solar access. 3. Required outdoor space can be shared between adjacent Building Types, as long as the cumulative minimum requirements for each type are satisfied. J. Landscape The landscape standards regulate the design of common open space including the amount of common open space that is required to be planted with vegetation. Figure 2-2 - Maximum Footprint per Story Diagram The maximum Footprint per Story is computed based on the building's ground floor Footprint, not the overall site area. Common Open Space J � I I I I I I J I Building 1 Building 2 Figure 2-3 - Common Open Space Diagram Adjacent buildings may combine the required outdoor spaces into one shared space provided the cumulative minimum requirements for each building is met. to )or 15 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • ALLOWABLE BUILDING TYPES 2.3 Allowable Building Types Allowable Building Types are as described in this section, 2.3 and summarized in Table 2-1. Table 2-1: Building Type Matrix Building Type Typical Height Frontage Width Common Uses (Land use shall conform Zoning•. Duplex/Triplex/ Fourplex 1-3 Stories 50-90 feet Small Multifamily 18-26 ft/unit Townhouse 2-4 Stories (Maximum string Residential, fee simple ownership (Attached Row) length is 200 feet) Flex/Loft or Shopfront, Live- 2-4 Stories 18-26 ft/unit Small business + Residential Work Auto Court or Six/ Eight Pack 2-4 Stories Varies Rental or Condo Multifamily Walk -Up Flats 2-3 Stories 75-150 feet Rental or Condo Multifamily Used to line the rear of edge parking Carriage House 2-3 Stories 50-120 feet lots of apartment communities where those parking lots front streets or alleys Small Mixed -Use Along sites fronting commercial Building 2-3 Stories 50-100 feet corridors where ground floor retail is desired Courtyard 3-5 Stories 50-75 feet Rental or Condo - Multi -family with Multifamily Ancillary Mixed -Use Residential wrapped around struc- Wrap Building 4-6 Stories 150-250 feet tured parking, often with ground floor retail • Urban Block 3-5 Stories 100-200+ feet Mixed -use, residential above retail (Over Podium) Mixed -Use Big Box 55-75 feet Up to 300 feet Residential over a large format retail store Ak Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 16 DIAMOND BAR BUILDING TYPE STANDARDS • DUPLEX, TRIPLEX, FOURPLEX Figure 2-4 - Duplex, Triplex, Fourplex Diagram 2.3.1 Duplex, Triplex, Fourplex A. Intent Statement A structure that consists of two to four primary dwelling units. B. Applicability All multifamily and mixed -use zones. C. Fagade Width Maximum Facade Width is 90 feet. D. Building Height & Massing 1. Maximum Height is Three stories. 2. The second and third stories may occupy the full ground floor Footprint area. 3. Attic space may be occupied and not count as a Story. Occupiable attic space shall not exceed fifty percent (50%) of the ground floor Footprint area. 4. Building Faces abutting side streets or yards shall provide at least 1 Horizontal Plane Break of at least three feet, and one vertical Plane Break of at least two feet. E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types 1. Permitted Frontage Types for street facing units: Front Porch and Stoop. (See Sections 4.5 and 4.7) 2. No specified Frontage types are required for non -street or paseo facing units. G. Pedestrian Access & Entries 1. At least one (1) Primary Entrance to a dwelling unit shall be accessed directly from and face the street or paseo. 2. Where an alley is not present, parking and services shall be accessed by a Driveway, consistent with DBCC Section 22.30.080. 3. On a corner lot without access to an alley, parking and services shall be accessed from the side street, by a Driveway consistent with DBCC Section 22.30.080. 4. Buildings that do not front a street must front a courtyard or paseo and have at least one Primary Entrance to a dwelling unit accessed directly from the courtyard. 5. Multiple front doors shall not be placed within 10 feet of one another unless there is a porch - at least six feet in depth in front of them. H. Parking 1. Parking may be accommodated at grade on the lot, in a common surface lot, in a carport, in a garage on the lot, or in a common garage. 2. Tandem spaces are permitted. 3. Parking shall be at the rear of the lot or in the middle of the Block, separated and screened from view from the street. 4. Where parking is integral with the building, garage doors shall not face the primary street but may face a secondary street if the building is on a corner lot. 17 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS DUPLEX , TRIPLEX, FOURPLEX 5. Guest parking spaces may be accommodated with on -street spaces along streets and alleyways adjacent to the building. All on - street parking shall be subject to all applicable regulations, including the Development Code and California Vehicle Code. 6. Where parking abuts a side street, it shall be screened from view pursuant to DBCC Section 22.30.070(8). I. Common Open Space 1. At least 15 percent of the Lot Area shall be provided as common open space. 2. Common Open space types that count toward the satisfaction of the required amount of outdoor space are porches, patios, verandas, balconies, yards, and decks. 3. Landscaped outdoor space shall be planted with native or adapted landscape. 4. Where courtyards are used to satisfy open space requirements, the courtyard shall be enclosed on at three sides by building walls or shall include at least one building or unit entrance on each side of the courtyard. 5. Common Open Spaces a. Each residential unit shall be provided a direct, pedestrian path of travel to common open spaces. b. Amenities that may be counted toward open space requirements: tot lot/play structure, community garden, picnic tables and BBO area, swimming pool, indoor recreation facility, sport courts, and natural open space. J. Landscape All outdoor space shall be landscaped or Hardscaped. K. Additional Standards Figure 2-5 - Duplex, Triplex, Fourplex Illustrative Photo 1. Where a project includes no more than two buildings, the buildings may be identical in design 2. Where more than two buildings are on a site, no more than two may be designed as identical and must differ by meeting at least four of the criteria identified in Section 3.2. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 18 BUILDING TYPE STANDARDS • TOWNHOUSE Figure 2-6 - Townhouse Diagram 2.3.2 Townhouse A. Intent Statement A structure that consists of at least three primary residences with common walls, side by side along the Building Frontage. The structure has parking behind the building, either integrated with the building or in surface spaces accessed from an alley. Alternatively, parking may be part of a structure shared with other Building Types. Townhouses may also wrap the base of a Podium. (See Figure 2-10). B. Applicability All multifamily and mixed -use zones. C. Fagade Width 1. Maximum of 26 feet for each Townhouse unit, except that the Fagade Width of a Townhouse on Block corners may be up to 45 feet per Frontage. 2. The maximum length of a string of attached D. Building Height & Massing See DBCC Section 22.08.040 for Height limits in the multifamily zones. In mixed -use zones, the maximum Height shall be 45 feet. See DBCC Section 22.16.060 for Height measurement and Height limit exceptions. Notwithstanding the foregoing, where topography requires a Stoop to access the ground floor, the Height shall be measured from the top of the Stoop. (See Section 4.5) 2. Fagade Strings shall have at least one Encroachment per 100 linear feet, such as a porch, balcony, or Plane Break. The combined length of Plane Breaks shall occupy at least 10 percent of the Fagade length. 3. Building Faces abutting side streets or yards shall provide at least one Horizontal Plane Break of at least three feet, and one vertical Plane Break of at least two feet. 4. In a three -Story building, a two -Story Townhouse may be stacked over a separate ground- floor unit. (See Figure 2-7) E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types Permitted Frontage Types: Stoop, Dooryard (See Sections 4.5 and 4.6). G. Pedestrian Access & Entries The Primary Entrance shall be accessible directly from the street, through the Frontage or from the fronting paseo. H. Parking 1. Garages shall accommodate no more than two cars and shall be integrated into the back of the Townhouse, behind a habitable room. 2. Parking may be accommodated on surface lots, behind the structure. Townhouses is 200'. 3. Podium parking is permitted, in which case a unit may also be accessed from the parking area or internal building corridor, and no individual garage parking is required. 19 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • TOWNHOUSE ENTRAN 1-STORY 4. Parking in garages or perpendicular spaces accessed from the front of the building are not permitted. I. Common Open Space 1. Amount required. At least 10 percent of the Lot Area shall be provided as common open space. 2. Types. Permitted common open space types that count toward the required amount of open space are: elevated Terraces, patios, verandas, balconies, yards, decks, and roof gardens 3. Design. The common open space area must be open to the sky, except for any allowable Encroachments, as permitted in Section 3.8, and any Shade Structures within the space. J. Landscape All common open space shall be landscaped or Hardscaped. Figure 2-7 -Illustration of a Townhouse Stacked over a Separate Flat i Permitted Outdoor Figure 2-9 - Section of a Townhouse Figure 2-10 - Section of a Townhouse Wrapping the Podium of Garage Figure 2-11 - Section of a Townhouse on a Sloping Site Figure 2-8 - Townhouse Illustrative Photo Figure 2-12 - Section of a Townhouse Not Permitted Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 20 BUILDING TYPE STANDARDS • FLEX/LOFT BUILDING Figure 2-13 - Flex/Loft Building Diagram 2.3.3 Flex/Loft Building A. Intent Statement Flex/Loft Building is a structure in which each unit functions as an integrated residence and work space. These units are typically arranged side by side along the Principal Frontage and are designed or structurally modified to accommodate joint residential and work occupancy. Flex/Loft Buildings may also wrap the base of a Podium structure. B. Applicability Mixed -use zones only. C. Fagade Width 1. A maximum of 30 feet for each flex/loft unit. Except that the Fagade Width of a Flex/Loft Building on Block corners may be up to 45 feet Frontage. 2. The maximum number of attached flex/loft units is a 10-1`agade String. D. Building Height & Massing 1. Maximum Height shall be 45 feet. 2. Fagade Strings shall have at least one Encroachment per 100 linear feet, such as a porch, balcony, or Plane Break. The combined length of Plane Breaks shall occupy at least 15 percent of the Fagade length. 3. Building Faces abutting side streets or yards shall provide at least one Horizontal Plane Break of at least three feet, and one vertical Plane Break of at least two feet. E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types Permitted Frontage Types: Shopfront, Commercial and Residential Terrace, Dooryard (See Sections 4.3, 4.4, 4.6, 4.9). G. Pedestrian Access & Entries The Primary Entrance shall be accessible directly from the street, through the Frontage, except that primary residential entries may be accessed through work space, through a fronting paseo between units, or from the rear. H. Parking 1. Individual garage parking may be integrated into the back of the Flex/Loft Building but must be behind a habitable room. 2. Parking may be on a surface lot behind the structure. 21 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS FLEX/LOFT BUILDING I. Common Open Space 1. Amount required. At least 15 percent of the Lot Area shall be provided as common open space. 2. Types. Permitted common open space types that count toward the required amount of open space are: elevated Terraces, patios, verandas, balconies, yards, decks, and roof gardens. 3. Design. The common open space area must be open to the sky, except for any allowable Encroachments, as permitted in Section 3.8, and any Shade Structures within the space. J. Landscape All common open space shall be landscaped or Hardscaped. Figure 2-14 - Flex/Loft Building Illustrative Photo Akl Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 22 DIAMOND BAR BUILDING TYPE STANDARDS • AUTO COURT OR SIX/EIGHT PACK Street ,, Figure 2-15 - Auto Court or Six/Eight Pack Diagram 2.3.4 Auto Court or Six/Eight Pack A. Intent Statement A building or an arrangement of buildings that contains between six and eight residential units that share a common Driveway. The primary pedestrian access shall be located from a Street, Open Space or Common Walkway. In mixed -use zones, the ground floor of each unit may include ground -floor retail or commercial uses. Auto Courts may be paired, creating common walkways or courtyards. However, this pairing is permitted no more than three times in a row. Services, utilities and trash container areas shall be located on the Common Driveway. B. Applicability All multifamily and mixed -use zones. C. Fagade Width The width of the Fagade may vary. D. Building Height & Massing 1. Maximum Height: As permitted in the applicable zoning district, but no taller than four stories. 2. The upper stories may occupy the full ground floor Footprint area. 3. Maximum building dimension along primary street Frontages: 50 feet. Along side streets, Fagades longer than 50 feet in length shall provide at least one Vertical Plane Break of at least two feet. E. Maximum Upper -Level Frontage Occupancy Not Applicable. F. Frontage Types Permitted Frontages: Stoop, Dooryard, Front Porch and along the street only Shopfront and Raised Commercial Terrace are also permitted. (See Sections 4.3, 4.4, 4.5, 4.6, 4.7) G. Pedestrian Access & Entries 1. Primary access to ground -floor spaces shall be directly from the street or common walkway or open space. 2. The Common Walkway shall connect to a Street or Open Space, not to an Alley or Driveway, on at least one end. 3. Primary pedestrian access is not permitted from an Alley. H. Parking 1. Parking and services shall be accessed through a Driveway or an alley. 2. Garages may be integral with or detached from the primary dwelling and they shall face the Common Driveway. 23 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS e AUTO COURT OR SIX/EIGHT PACK I. Common Open Space Not required. However, where Auto Courts are paired to create a common walkway the following Standards apply: The front Setback along the Common Walkway shall be at least 10 ft from the center -line of the sidewalk resulting in a Building Face to Building Face width of at least 20 feet. 2. The Common Walkway shall measure at least five feet in width. 3. Unenclosed porches may encroach into the Setback by up to seven feet provided that they are no higher than four feet above grade. 4. Fences, walls or hedges are allowed along the Common Walkway at fronts of homes, provided they are Setback from the walkway by at least two feet and are no taller than three feet from the Grade of the Common Walkway. 5. Bay windows may encroach into the Setback by up to two feet. J. Landscape 1. The Common Walkway path shall be a minimum of five feet in width. 2. All common open space shall be landscaped or Hardscaped. 3. Fences, walls or hedges are allowed along the Common Walkway at fronts of homes, provided they are Setback from the walkway by at least two feet and are no taller than 42 inches from the Grade of the Common Walkway. Figure 2-16 - Autocourt or Six/Eight Pack Illustrative Photo Figure 2-17- Autocourt or Six/Eight Pack Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 24 DIAMOND BAR BUILDING TYPE STANDARDS • WALK-UP FLATS Figure 2-18 - Walk -Up Flats Diagram 2.3.5 Walk -Up Flats A. Intent Statement D. Building Height & Massing 1. Maximum Height: Three stories. 2. Upper stories may occupy the full ground floor Footprint area. 3. Attic space may be occupied and not count as a Story. Occupiable attic space shall not exceed 50% of the ground floor Footprint area. 4. Building Faces abutting side streets or yards shall provide at least one Horizontal Plane j Break of at least three feet, and one vertical Plane Break of at least two feet. 5. Where the building is repeated, each building shall front the primary street or the perimeter of a Block. 6. Repeated buildings shall be provided with different materials, colors and/or Architectural Styles. 7. No more than three walk-up units may be attached in a row per floor. Of these, no more than two adjacent units may have identical Fagades. A structure that consists of four to 12 dwelling units accessed from one common staircase accommodating up to four units per floor. The building may contain residential or commercial uses on the ground floor with residential uses above. The Walk-up may be repeated along a primary Frontage or within a Block subject to the massing requirements of the Building Type. B. Applicability All multifamily and mixed -use zones. C. Fagade Width Maximum Fagade Width is 150 feet. However up to three Walk -Up Buildings may be adjoined provided that each building appears as a separate structure from the adjacent one. Methods for achieving this are included in Section 3.2. 8. A fourth walk-up unit may be added at the end of the row if it is designed to turn the corner. This pattern may be repeated on each floor. 9. Buildings may be grouped to form a courtyard. E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types Permitted Frontages: Stoop, Dooryard, Front Porch and along the street only Shopfront and Raised Commercial Terrace are also permitted. (See Sections 4.3, 4.4, 4.5, 4.6, 4.7) 25 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • WALK-UP FLATS G. Pedestrian Access & Entries 1. All units shall be accessed from a common stair lobby. However, ground floor units may also be accessed from the primary street. 2. Primary pedestrian access to the common stair lobby shall be provided from the street, a fronting mews or a common courtyard. A second access may be provided from the rear. 3. Primary pedestrian access is not permitted from an alley. H. Parking 1. Parking shall be accommodated at grade and/ or tuck -under at the rear of the building, in a common surface lot in the middle of the Block, or against an alley. Connectivity to adjacent parking lots where present shall be provided. 2. Surface lots that face an alley shall be screened from view from the side street by a garden wall, fence or hedge. 3. Services, utilities and trash container areas shall be located off the alley, where present. 4. Parking and services shall be accessed from an alley where present. 5. Where an alley is not present, parking and services shall be accessed by a Driveway, consistent with DBCC Section 22.30.080 (subject to approval by the Fire Department) or by adjacent parking areas. 6. On a corner lot without access to an alley, parking and services shall be accessed from the side street by a Driveway consistent with DBCC Section 22.30.080, unless a greater width is required by the Fire Department. I. Common Open Space 1. Amount required. At least 15 percent of the Lot Area shall be provided as common open space. 2. Types. Permitted common open space types that count toward the satisfaction of the required amount of outdoor space are: elevated Terraces, patios, verandas, balconies, yards, decks, and roof gardens. Figure 2-19 - Walk -Up Flats Illustrative Photo 3. Design. The common open space area must be open to the sky, except for any allowable Encroachments (see Section 3.8) and any Shade Structures within the space. J. Landscape 1. All outdoor space shall be landscaped or Hardscaped. 2. At least 25 percent of the required on -site outdoor space shall be planted with ground cover, shrubs, trees, or a combination thereof. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 26 BUILDING TYPE STANDARDS • CARRIAGE HOUSE Figure 2-20 - Carriage House Diagram 2.3.6 Carriage House A. Intent Statement A structure composed of residential units above at least partially -enclosed ground -floor parking spaces. The parking is accessed from an alley or surface parking lot, while the residential units are accessed from the street or pedestrian path. The residential space need not be directly connected to the parking. Especially suitable as liner buildings, carriage houses can be used to screen surface parking lots from the primary street. Garden Style Apartments are most similar to this Building Type. B. Applicability All multifamily and mixed -use zones. D. Building Height & Massing 1. Maximum Height: Three stories. 2. The second and third stories may occupy the full ground floor Footprint area, so long as it is within the Floor Area Ratio (FAR) allowed for that zoning district. 3. Fagade Strings shall have at least one Encroachment per 100 linear feet, such as a porch, balcony, or Plane Break. The combined length of Plane Breaks shall occupy at least ten percent of the Fagade length. 4. Building Faces abutting side streets or yards shall provide at least one Horizontal Plane Break of at least three feet, and one vertical Plane Break of at least two feet. E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types 1. Permitted Frontage Types: Front Porch, Stoop, and Raised Residential Terrace. (See Sections 4.5, 4.7, 4.9) 2. Front Setbacks per Zoning Standards. 3. A carriage house's ground floor shall be designed so that the street -facing side appears to be habitable. G. Pedestrian Access & Entries 1. The Primary Entrance to the building shall be accessed directly from and face the street or pedestrian path. 2. A secondary entrance may be provided from the rear parking spaces. C. Fagade Width 3. Parking and services shall be accessed through Maximum Fagade Width is 120 feet. the alley or surface parking lot. ■ V 27 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • CARRIAGE HOUSE H. Parking 1. Parking spaces shall face the alley or surface parking lot and be screened from view from the side street by a garden wall, fence or hedge. 2. Tandem spaces are permitted. 3. Parking spaces do not have to correspond with the residential unit above. 4. Parking spaces do not need to be fully enclosed. 5. Services, utilities, and trash container areas shall be located on the alley or in the surface parking lot. I. Common Open Space Not required. J. Landscape To the extent it is provided, an outdoor space shall be landscaped or Hardscaped. Figure 2-21 - Concept Rendering of Carriage House Figure 2-22 - Carriage House Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 28 DIAMOND BAR BUILDING TYPE STANDARDS • SMALL MIXED -USE BUILDING j Figure 2-23 - Small Mixed -Use Building Diagram 2.3.7 Small Mixed -Use Building A. Intent Statement A low -scale building that includes ground -floor non-residential uses such as retail, service, or office, with one or more residential uses located on the upper floors. This Building Type is intended for sites fronting commercial corridors or neighborhood centers and is typically two to three stories in Height. B. Applicability Mixed -use zones only. C. Fagade Width Maximum Fagade Width is 100 feet. D. Building Height & Massing 1. Maximum Height: 45 feet. 2. The upper stories may occupy the full ground floor Footprint area. E. Maximum Upper -Level Frontage Occupancy Not applicable. F. Frontage Types 1. Permitted Frontages: Stoop, Shopfront and Raised Commercial Terrace. (See Sections 4.3, 4.4, 4.5) 2. Ground -floor Fagades shall include retail, office, or work space uses that occupy at least 50 percent of the ground -floor depth and extend across a minimum of 60 percent of the primary Fagade Width. At least 60 percent of the primary ground -floor Fagade between two and ten feet above Sidewalk Grade shall consist of transparent windows that provide direct views into the occupied space. G. Pedestrian Access & Entries 1. Primary access to ground -floor spaces shall be directly from the street. 2. Building and retail entrances fronting primary and side streets shall remain accessible and unlocked during regular business hours. 3. Primary Entrances to upper floors shall be accessed through: • Entrance in the rear. • A lobby that is accessed directly from the street. • Stoops entered from the street. H. Parking 1. Parking shall be an alley -loaded lot and/or parallel on -street. 29 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS SMALL MIXED -USE BUILDING 2. Where no alley is present, parking may be accessed via a Driveway and from the primary and/or secondary street. Such Driveways may include parking along one side, making the total parking area exposed to the street no greater than 45 feet. Parking spaces shall be screened from view from the fronting street, by a low wall, fence or hedge consistent with DBCC Section 22.16.080 (5). (See Figure 2-24) I. Common Open Space Not required. J. Landscape See DBCC Chapters 22.24, 22.26 and Section 22.20.070 for parking lot landscaping standards. Figure 2-24 - Small Mixed -Use Building Diagram Mom= La- "-Ii Figure 2-25 - Small Mixed -Use Building Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 30 BUILDING TYPE STANDARDS • COURTYARD MULTIFAMILY BUILDING 55 M/ 7�L� 225' MAX — MAX Figure 2-26 - Courtyard Multifamily Building Diagram 2.3.8 Courtyard Multifamily Building A. Intent Statement A grouping of Townhouses, walkups, or other multifamily buildings arranged on a site around a central courtyard or series of courtyards at grade or above a parking Podium. The building may contain residential, commercial, or a combination of these uses. Parking is provided below ground or accommodated in up to two above -grade Podium Levels. B. Applicability All multifamily and mixed -use zones. C. Fagade Width The maximum length of any portion of the Fagade that sits along a Build -to -Line shall not exceed 75 feet. D. Building Height & Massing are permitted for other Building Types within the same zone. 2. The maximum length of the entire courtyard ensemble shall not exceed 225 feet. This includes the building mass plus the side of the courtyard that is open to the Frontage. Maximum Allowed Footprint per Story 12 3 4 5 2% 100% - - - 3 100% 80% - 4 100% 100% 80% - 5 100% 100% 80% 80% E. Maximum Upper -Level Frontage Occupancy Portions of Fagades above 45 feet in Height and greater than 150 feet in length shall occupy no more than 80% of the Primary Fagade Plane established on the ground floor. F. Frontage Types Permitted Frontage Types are: Forecourt, Shopfront, Raised Commercial Terrace, Urban Frontage, and Dooryard. (See Sections 4.3, 4.4, 4.6, 4.8, 4.10) G. Pedestrian Access & Entries The internal courtyard shall be accessible from the street, through the Frontage. If the internal courtyard is located above the Ground Plane, a public stair, with treads and risers at least eight feet in width, and incorporating Architectural Features consistent with the building's Architectural Style is required. Access may be gated. 2. The Primary Entrance to each ground -floor unit shall be directly from the street or courtyard. Entrances shall occur at a maximum interval of 60 feet. 1. Maximum building Height shall comply with 3. Primary access to units above the ground floor the Height limits of the underlying zoning shall be through a lobby accessed from the district, but shall not exceed 65 feet under any street or the courtyard. circumstance, including where greater Heights 31 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • COURTYARD MULTIFAMILY BUILDING H. Parking 1. Parking may be accommodated in surface lots with or without tuck under parking or in two levels of above -ground Podium or below ground parking or both. 2. A liner of habitable space shall conceal above- ground Podium parking garages from view. 3. Residential parking shall be separate from retail parking, except for any residential guest parking. I. Common Open Space I: 3 Q 5. Amount required. At least 15 percent of the Lot Area shall be provided as common open space. Types. Permitted common open space types that count toward the satisfaction of the required amount of common open space are: patios, verandas, and courtyards. Dimensions. The minimum courtyard dimension shall be 30 feet on each side for buildings. If the courtyard is surrounded by three or more sides or if the building is three or more stories, the minimum dimension on each side shall be 40 feet. Encroachments. Encroachments into the common open space are permitted on all sides, provided that the minimum 30-foot dimension is maintained, exclusive of the Encroachments. Design. The common open space area must be open to the sky, except for any allowable Encroachments (see Section 3.8) and any Shade Structures within the space. J. Landscape I% All outdoor space shall be landscaped or Hardscaped. At least 25 percent of the required on -site common open space shall be planted with ground cover, shrubs, trees, or a combination thereof. 1 t' it, VT0\00'07F\ Figure 2-27 - Courtyard Building Illustrative Photo Courtyard View of a Courtyard Building Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 32 BUILDING TYPE STANDARDS • WRAP BUILDING Garage Wrap- --- PrimarY Street i Figure 2-28 - Wrap Building Diagram 2.3.9 Wrap Building A. Intent Statement A building and garage ensemble where the building directly fronts the street and wraps around an above -ground garage. The building may contain residential, commercial, or a combination of these uses. The garage may either be attached to or detached from the building. B. Applicability Mixed -use zones only. C. Fagade Width 1. Maximum 250 feet. 2. Blank walls (defined as having no active use, glazing or doorway) shall be limited to 20% or 40 feet of the Building Fagade, whichever is less along all required streets. This requirement is not applicable for Fagades along service or fire lanes and alleys. D. Building Height & Massing The maximum Height shall comply with the Height limits of the underlying zoning district, but shall not be less than 35 feet, nor exceed 75 feet under any circumstances, including where greater Heights are permitted for other Building Types within the same zone. 2. The maximum garage Height shall be 55 feet excluding shading devices or photovoltaic panels. 3. The maximum allowed Footprint per Story shall be determined by the following table: Maximum Allowed Footprint per Story P5 4 1-2 3 4 2' 100% - - - 3 100% 90% - 4 100% 90% 75% - 5 100% 1000/. 85% 75% E. Maximum Upper -Level Frontage Occupancy Portions of Fagades above 55 feet in Height and greater than 150 feet in length shall occupy no more than 70% of the Primary Fagade Plane established on the ground floor. F. Frontage Types Permitted Frontage Types are Forecourt, Shopfront, Raised Commercial Terrace, Raised Residential Terrace, Urban Frontage, Stoop, and Dooryard. (See Sections 4.3, 4.4, 4.5, 4.6, 4.8, 4.9, 4.10) G. Pedestrian Access & Entries 1. Primary Entrances to upper floors shall be accessed through an interior courtyard or lobby, accessed directly from the street. 2. Primary access to the ground -floor residential space shall be directly from the street. 3. All retail spaces shall be accessed from a ground -floor, single -tenant entry along a street, courtyard, or Paseo. 33 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • LINEAR BUILDING WITH GARAGE 4. Primary retail entrances shall remain accessible and unlocked during regular business hours. 5. In addition to the building's required Primary Entrances, there may be ancillary entrances to the building from parking garages. H. Parking Not applicable. I. Common Open Space 1. Amount required. At least 10 percent of the Lot Area shall be provided as common open space. 2. Types. Permitted common open space types that count toward the satisfaction of the required amount of common open space are: patios, verandas, courtyards, and roof gardens. 3. Dimensions. Each common open space shall have a minimum dimension of 20 feet on each side. 4. Encroachments. Encroachments into the outdoor space are permitted on all sides, provided that the minimum 20-foot dimension is maintained, exclusive of the Encroachments. 5. Design. The common open space area must be open to the sky, except for any allowable Encroachments and any Shade Structures within the space. J. Landscape 1. All common oopen space shall be landscaped or Hardscaped. 2. At least 25 percent of the required on -site common open space shall be planted with ground cover, shrubs, trees, or a combination of thereof. Landscaping in pots or Planters may be included in computing the total Landscaped Area. Figure 2-29 - Wrap Building Illustrative Photo Street view of a linear building. The Fagade does not reveal the parking use behind. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 34 BUILDING TYPE STANDARDS • URBAN BLOCK kx Figure 2-30 - Urban Block Diagram 2.3.10 Urban Block A. Intent Statement A building designed for occupancy by retail, service, office, and/or residential uses on the ground floor, with upper floors also configured for office and/or residential uses, however two - Story retail is permitted. Parking is usually accommodated below ground. B. Applicability Mixed -use zones only. C. Fagade Width 1. Maximum is 225 feet. 2. Blank walls (defined as having no active use, glazing or doorway) shall be limited to 20% or 40 feet of the Building Fagade, whichever is less, along all required streets. This requirement is not applicable for Fagades along service or fire lanes and alleys. D. Building Height & Massing 1. Maximum Height: 75 feet. 2. The maximum allowed Footprint per Story shall be determined by the following table: Maximum Allowed Footprint per Story 12 3 4 >5 2-3 100% 4-5 100% 85% 75% - > 5 100% 100% 85% 75% E. Maximum Upper -Level Frontage Occupancy Portions of Fagades above 55 feet in Height and greater than 150 feet in length shall occupy no more than 70% of the Primary Fagade Plane established on the ground floor. F. Frontage Types Permitted Frontage Types are Forecourt, Shopfront, Raised Commercial Terrace, Raised Residential Terrace, Urban Frontage, Stoop, and Dooryard. (See Sections 4.3, 4.4, 4.5, 4.6, 4.8, 4.9, 4.10) G. Pedestrian Access & Entries 1. Primary Entrances to upper floors shall be accessed through: 1. an interior courtyard or 2. a lobby, which is accessed directly from the street. 2. Primary access to the ground -floor residential space shall be directly from the street. 3. All retail spaces shall be accessed from a ground floor single tenant entry along a street, courtyard or paseo, remain accessible and unlocked during regular business hours. 35 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS o URBAN BLOCK H. Parking 1. Parking may be accommodated in up to two levels of above -ground Podium, below ground, or both. 2. A liner of habitable space shall conceal above- ground Podium parking garages from view. I. Common Open Space 1. Amount required. At least 15 percent of the Lot Area shall be provided as common open space. 2. Types. Permitted common open space types that count toward the satisfaction of the required amount of common open space are: patios, verandas, courtyards, and roof gardens. 3. Dimensions. Each common open space shall have a minimum dimension of 20 feet on each side. 4. Encroachments. Encroachments into the common open space are permitted on all sides, provided that the minimum 20-foot dimension is maintained, exclusive of the Encroachments. 5. Design. The common open space area must be open to the sky, except for any allowable Encroachments and any Shade Structures within the space. J. Landscape 1. All common open space shall be landscaped or Hardscaped. 2. At least 25 percent of the required on -site common open space shall be planted with ground cover, shrubs, trees, or a combination of thereof. Landscaping in pots or Planters may be included in computing the total Landscaped Area. A- 006 / r1 Figure 2-31 - Urban Block Illustrative Photo Figure 2-32 - Urban Block Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 36 BUILDING TYPE STANDARDS • MIXED -USE BIG BOX Figure 2-33 - Mixed -Use Big Box Diagram 2.3.11 Mixed -Use Big Box A. Intent Statement This Building Type provides additional flexibility for developments incorporating a supermarket or other large format retailer. B. Applicability Mixed -use zones only. C. Fagade Width 1. Maximum 300 feet. 2. Blank walls (defined as having no active use, glazing or doorway) shall be limited to 20% or 40 feet of the Building Fagade, whichever is less along all required streets. This requirement is not applicable for Fagades along service or fire lanes and alleys. D. Building Height & Massing 1. Maximum building Height shall comply with the Height limits of the underlying zoning district, but shall not exceed 75 feet under any circumstance, including where greater Heights x are permitted for other Building Types within the same zone. 2. Minimum Height is 55 feet. 3. The maximum retail floor plate is 65,000 sf. 4. The maximum allowed Footprint per Story shall be determined by the following table: iw Maximum Allowed Footprint per Story 13 4 5 2-3 100% - - 4 100% 90% - 5 100% 90% 75% E. Maximum Upper -Level Frontage Occupancy In zoning districts where such Heights are permitted, portions of Fagades above 45 feet in Height and greater than 150 feet in length shall occupy no more than 80% of the Primary Fagade Plane established on the ground floor. F. Frontage Types Permitted Frontage Types are Forecourt, Shopfront, Raised Commercial Terrace, Raised Residential Terrace, Urban Frontage, Stoop, and Dooryard. (See Sections 4.3, 4.4, 4.5, 4.6, 4.8, 4.9, 4.10) G. Pedestrian Access & Entries 1. Primary Entrances to upper floors shall be accessed through a lobby, accessed directly from the street or from a courtyard. 2. Primary access to the ground -floor retail space shall be directly from the street and shall occur at a maximum interval of 60 feet. Retailers over 30,000 sf must have at least two entrances. 37 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING TYPE STANDARDS • MIXED -USE BIG BOX 3. All retail spaces shall be accessed from a ground -floor, single -tenant entry along a street, courtyard, or alley. 4. Primary retail entrances shall remain accessible and unlocked during regular business hours. 5. In addition to the building's required Primary Entrances, there may be ancillary entrances to the building from parking garages. H. Parking 1. Above -ground garages shall be concealed from view along the street for the first 21 feet of Height through a liner of habitable space. 2. Above 21 feet, above -ground garages shall be screened from view along the street by habitable space or by landscaping, outdoor screens, or cladding. I. Common Open Space Not required. J. Landscape All outdoor space shall be landscaped or Hardscaped. See DBCC Chapters 22.24, 22.26 and Section 22.20.070 for parking lot landscaping standards. Figure 2-34 - Mixed -Use Big Box Illustrative Photo Figure 2-35 - Mixed -Use Big Box Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 38 DIAMOND BAR BUILDING ARTI( STAN Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • PURPOSE BUILDING ARTICULATION STANDARDS 3.1 Purpose The desired pedestrian scale and character of Diamond Bar requires that new project development not appear as massive, monolithic structures, but instead as a series of smaller scale buildings. The standards of this section are intended to ensure that larger projects are designed to appear as carefully conceived groups of separate structures that, along with an attractive streetscape, contribute to the overall urban, pedestrian - friendly quality desired for Diamond Bar. Ak Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 40 DIAMOND BAR Page Left Intentionally Blank 41 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • BUILDING ARTICULATION TECHNIQUES 3.2 Building Articulation Techniques Table 3-1: Building Articulation Standards Matrix Min. Number of Buildin Articulation'WM� Techniques Fagade LiagAm The table above outlines the minimum number of building articulation techniques —listed below —that must be applied based on the building's Fagade length: 1. Horizontal Articulation 2. Vertical Articulation 3. Architectural Projections 4. Architectural Recessions 5. Fagade Differentiation 6. Architectural Style Differentiation 7. Base, Middle, and Top Articulation Figure 3-1 - Multiple Variations of Same Style Figure 3-2 - Mixed -Use Building Articulated with Corner Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 42 DIAMOND BAR BUILDING ARTICULATION STANDARDS • DIAGRAMS 1. Horizontal Articulation Step a portion of the street -facing Fagade forward or backward from the predominant Fagade Plane a minimum of six feet for a minimum distance of 25 feet. 2. Vertical Articulation Step a portion of the street -facing Fagade upward or downward from the Predominant Building Height a minimum of four feet for a minimum distance of 25 feet. This technique is useful for "stepping down" the scale of a new building adjacent to an existing smaller building. 3. Architectural Projections Append or project balconies, bay windows, cantilevered rooms, roof overhangs or Eaves and/or awnings. Provide at least one Projection of at least two feet in depth and three feet in width per every 50 feet of Fagade length. Figure 3-3 - Horizontal Articulation Diagram Figure 3-4 - Vertical Articulation Diagram Figure 3-5 - Architectural Projections Diagram Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • DIAGRAMS 4. Architectural Recessions Recess Architectural Features or spaces - such as porches, covered passages, balconies, and windows - into the plane at intervals of 50 feet on center along the Fagade length. a. Porches, covered passages, and balconies must be recessed by a minimum of six feet from the front plane of the Fagade to be considered a recession. b. Windows must be recessed by a minimum of five inches from the \ front plane to be considered a recession. 5. Fagade Differentiation Organize the Fagade with two or three distinct compositions. Distinctions may include material and/or color combinations for each apparent Fagade. A change in the length of a composition does not constitute a distinct composition. 6. Architectural Style Differentiation Design the Fagade to include at least two Architectural Styles (from Chapter 6), with no one style occupying less than 30 percent of the total Fagade. Figure 3-6 - Architectural Recessions Diagram Figure 3-7 - Fagade Differentiation Diagram Figure 3-8 - Architectural Style Differentiation Diagram Style 3 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 44 BUILDING ARTICULATION STANDARDS • DIAGRAMS 7. Base, Middle, and Top Articulation Compose Building Facades with a Base, Middle, and Top on any street or paseo facing Facade. Buildings shall have a distinct "base" at the ground level whose Height is 10 percent to 35 percent of the building's total Height, and may include the ground floor (or part of the ground floor) and lower structural components that connect the building to its site. This may be accomplished with distinct materials, or distinct application of materials, and/or a horizontal expression line, such as a Water Table or Cornice, creating a transition to the upper floors. This feature shall extend across at least 80 percent of the Fagade length. The middle of the building shall have a Height comprising from 50 percent to 87 percent of the building's total Height. The top of buildings include articulation at the Parapet (for buildings with flat roofs) and/or the top floor, or below the Eave (for buildings with sloped roofs) that identifies the top of the building with a Cornice, color change, or material change. The top of the building shall have a Height of three to 10 percent of the building's total Height, but shall be less than the Height of the building base. Figure 3-9 - Base Middle and Top Articulation Diagram Cornice T.. _J Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • TRANSITION TO RESIDENTIAL DISTRICTS & ENTRANCES 3.3 Transition to Single -Family Residential Districts Where new mixed -use or multifamily development is adjacent to property developed with single-family residences or zoned for single-family residential use, the following standards shall apply: a. Height Envelope. No portion of a new structure shall extend above a plane starting at 30 feet in Height at the shared property line and projecting inward at a 45-degree angle from vertical toward the interior of the site, up to the maximum permitted building Height (see Figure 3-10). b.Reference Grade. The 30-foot measurement shall be taken from the finished grade of the adjacent single-family residential property (or single-family residentially zoned parcel), not from the grade of c.Architectural Style Restriction. The California Contemporary Style (see Section 6.6) shall not be permitted adjacent to Single -Family Residential Districts. A. 30' height B. 45-degree angle C. 50, maximum building height 'C i30 Property Line �= 10' 11-16, 3.4 Entrances 1. Primary Entrance. The Primary Entrance to buildings shall be in conformance with the requirements of the Building Type in Chapter 3. 2. Entrance Articulation. Special Paving, lighting, and landscaping shall be included at Primary Entrances to clearly identify the entrance and to enhance the overall building design. Figure 3-10 - Illustrative Diagram Figure 3-11 - Entrances A canopy, lighting, and a slight recess accentuate the Primary Entrance. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 461 BUILDING ARTICULATION STANDARDS • PASSAGEWAYS & WINDOWS & ROOD STANDARDS 3.5 Passageways 1. Pedestrian passageways shall be no less than 15 feet wide. 2. If pedestrian passageways are covered, they require a floor to ceiling Height of at least two times their width, but no greater than three times their width. 3. Passageways shall be lighted. 3.6 Windows 1. Design shall be according to the requirements of the Architectural Style in Chapter 7. 2. Glazing Transparency and Reflectance. All ground -floor and street -facing window glazing must have a Visible Light Transmittance (VLT) of at least 60%, and an Exterior Reflectance (ER) of no more than 15%. Highly reflective, mirrored, or heavily tinted glazing is prohibited. Opaque glazing may only be used as spandrel glass or where required for mechanical screening or privacy. Figure 3-12 - Windows Windows are recessed from the exterior wall surface. 3.7 Roof Standards 1. The roof edge shall be defined with a Parapet, Cornice, and overhang. 2. Rooftop mechanical equipment shall be clustered away from the edge of the building and behind/within an enclosure to be screened from the street. 3. Unenclosed Shade Structures, and similar amenities shall not exceed 16 feet in Height from the roof deck floor level and do not count as a Story. Figure 3-13 -Variety of Rooflines Illustrative Photo Apartment complex with a variety of rooflines. 47 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • ENCROACHMENTS AND PROJECTIONS 3.8 Encroachments and Projections The following are the permitted Encroachments and Projections into the front Setbacks. A. Awning and Canopy Encroachment and Projection Standards 1. Projection. May project up to the right-of-way line or 33 percent of the distance between the Building Face and the curb, whichever is less. 2. Support. Awnings and canopies shall be attached to the building. Support structures that connect to the ground are not permitted. 3. Clearance. Minimum vertical clearance for awnings and canopies is 10 feet if it is removable or retractable and 12 feet if it is fixed or permanent. Awnings shall not obscure storefront signs. 4. Materials. Awnings and canopies shall be constructed of canvas, durable woven fabric, or metal, and shall be consistent with the materials and detailing associated with the building's selected Architectural Style, as specified in Chapter 6. Vinyl, plastic, and visibly glossy or reflective materials are prohibited. Colors shall align with the approved color palette for the selected style. Translucent or backlit awnings are prohibited. Awnings and canopies shall be designed as integral components of the building and shall not appear as temporary or tacked -on features. Figure 3-14 - Encroaching Habitable Space Illustrative image of encroaching bays and Stoops. 5. Heights of awnings on a building shall be the same along the Fagade or Frontage line unless the building steps in relation to grade, in which case, the Heights of awnings shall be consistent with the head Heights of the windows and doors they are shading. B. Habitable Projecting or Encroaching Interior Space Standards Allowable Projection. Habitable projecting or encroaching interior spaces are a portion of the building enclosed by walls and a roof that extends beyond the Building Face (i.e. bay windows and other architectural Projections). They may project up to three feet from the Building Face, but shall not extend beyond the property line. 2. Length Along Building Face. No individual habitable projecting or encroaching interior space may exceed 15 feet in horizontal length. 3. Clearance. Minimum vertical clearance of upper Story projecting spaces shall be 16 feet from the adjacent Sidewalk Grade on storefront or storefront Terrace Frontages or 10 feet above other Frontage Types (see Chapter 4 for Frontage Types). C. Habitable Projecting or Encroaching Exterior Space Standards Balconies. Usable projecting or encroaching exterior spaces are spaces used by occupants that are not enclosed by walls and a roof, such as balconies. They shall not extend more than eight feet from the Building Face, or beyond the right-of-way line. Unless permitted by the Architectural Style, projecting balconies shall be no less than six feet in depth. Balconies shall be accessible from inside the building and shall not be completely enclosed. 2. Clearance. The minimum vertical clearance of non -habitable projecting or encroaching exterior spaces is 16 feet from the adjacent Sidewalk Grade above storefront Frontages or 10 feet above other Frontage Types (see Chapter 4 for Frontage Types). Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 48 BUILDING ARTICULATION STANDARDS • ENCROACHMENTS AND PROJECTIONS CONTINUED D. Interior and Exterior Projecting Habitable Space Standards Total Horizontal Length of Projecting Spaces. The total combined length of habitable interior and exterior projecting spaces along the Building Face shall not exceed 67 percent of the total length of the Building Face to which they are attached. 2. Total Horizontal Length of Encroaching Spaces. The total combined length of habitable and Non -Habitable Encroaching Spaces along the Building Face shall not exceed 50 percent of the total length of the Building Face to which they are attached. E. Rooftop Amenities 1. Rooftop amenities such as swimming pools are permitted; rooftop amenities do not count as a Story. Figure 3-15 - Projecting Canopies Canopies create a rhythm along the streetfront and accentuate the building entrances. F. Stoops 1. Stoops may encroach into the front Setback Area but shall not extend beyond the property line. G. Outdoor Furnishing Zones 1. Outdoor display/sales of merchandise may not encroach into Setback areas per DBCC Section 22.42.080 (2)(b). 2.Outdoor furnishing zones shall comply with DBCC Section 22.42.080 (3)(d). 3.General. Outdoor furnishings such as seating or merchandise displays shall comply with Sections 5.3 and 5.4. H. Subterranean Parking in Front Setbacks 1. Location in Setbacks & Alleys. Subterranean parking may extend into the front Setback, up to the property line (See Figure 3-16). Subterranean parking may also be located under alleys that are located within a development Block if utilities servicing the Block are not interrupted. i Encroachment Projection Area i i A i e I Property Line -4-s F Building D Figure 3-16 - Encroachment and Projections Diagram A. Projecting habitable space B. Projecting canopy C. Encroaching street furniture D. Subterranean parking (purple area) 49 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development BUILDING ARTICULATION STANDARDS • SHOPFRONTS IN MIXED -USE BUILDINGS 3.9 Shopfronts in Mixed -Use Buildings 1. Shopfronts shall have paving that is unique to the area in front of the shop within the Setback area, in order to differentiate the building entrance, but shall be designed with primary consideration of the public right-of-way. 2. Shopfronts along ground floor commercial spaces shall provide windows that constitute at least 60 percent of the Facade area of the shop itself, measured from the ground to the second - floor line, and from centerline to centerline of the shop's demising wall. 3. Where multiple retail tenants occupy one building, the same Height of awnings across an entire building shall be maintained. Building or Shopfront entries along the ground floor shall be equidistant, if feasible. Shopfronts shall be designed to be subdivided at 30-foot intervals for commercial leasing flexibility and functionality and to create a fine-grained rhythm along the Street. Figure 3-17 -Illustrative Photo of Shopfronts in Mixed -Use Buildings Architecturally -consistent detailing from signage and lighting fixtures, to colors and materials, enhance the character of the streetscape. 4. Blank Walls shall not be permitted along the Principal Frontage of large tenant spaces on the ground floor of mixed -use buildings. 5. Multiple entrances shall be incorporated for large stores along a Street front whose length spans the width of more than two typical shops (2 X 30 ft), or which front on more than one Street. 6. Rather than shadow window box displays, at least 65 percent of a retail Frontage shall include transparent glazing and at least 70 percent of the glazing shall allow views into the store. Mirrored or opaque films on windows that Block views into the store are not permitted. 7. A base below windows shall be between 18-30 inches in Height to protect glazing from foot traffic, while maintaining the characteristic of Height and openness. 8. Commercial grade entry doors with clear glazing framed in metal or wood shall be used. 9. Shopfronts shall use awnings, canopies, architectural lighting, and pedestrian signage to articulate shop entrances. uuuLL] Bottom F �� ❑❑ � I of interior ceiling 0 Tr w Width FIGlazing Area Figure 3-18 - Minimum Frontage Glazing Diagram The Frontage glazing area shall be measured from the finished floor to the bottom of ceiling of the ground floor. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 50 BUILDING ARTICULATION STANDARDS • COLORS AND MATERIALS 3.10 Colors and Materials 1. Changes of exterior color, texture, or material shall be accompanied by changes in plane so that buildings appear substantial and integral. 2. Color and material changes at the outside of corners of a building or plane change that give a Thin Veneer, or Faux Stone Appearance, shall not be used. Where the color or material extends to an outside corner, it shall continue around the corner to the next inside corner. Figure 3-19 - Changes of Colors and Materials Illustrative Photo Changes of exterior color, texture, or material shall be accompanied by changes in plane so that buildings appear substantial and integral. 51 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 52 FRS NTAGE r s Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES • STANDARDS AND GUIDELINES FRONTAGE TYPES 4.1 Purpose and Intent A building's Frontage is the interface between the Public Realm and private development. These standards recognize that the successful design of this interface significantly contributes to the realization of an active and engaging urban environment. Multifamily and mixed -use buildings will have ground -floor Frontages that are human -scaled, provide visual interest, and access to ground -floor uses. This section provides a palette of prototypical Frontage Types that are permitted. Standards include dimensional criteria, criteria for openings, as well as criteria for the Ground Plane immediately adjacent to the Frontage, such as minimum required glazing. Intent: In order for applications to be approved, each application shall meet the following criteria as applicable: a. Creates or maintains a pedestrian -oriented streetscape, b.Generates a transition from the public streetscape to each building and its site. The standards that follow provide objective and measurable standards that, when applied to the design of Frontages, fulfill this intent. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 54 FRONTAGE TYPES • EXPLANATION OF STANDARDS 4.2 Explanation of Standards This chapter provides standards for the following eight Frontage Types. For each Frontage Type, the standards described below are provided. See Table 4-1 for a summary of Frontage Types. It is possible to utilize more than one Frontage along the length of a Building Face. A. Frontage Intent Statement This statement describes the building -to -street relationship that each Frontage Type is meant to achieve. B. Entries These standards address entries at the street or paseo fronts, not those that are internal to the site, or on alleys. C. Dimensions Specific dimensions of features like massing, entry Height, openings, and Setbacks are delineated here. D. Paving and Landscaping This standard addresses the area between the property line and Building Face. Where paving is specified, it shall match the paving of the fronting sidewalk or consist of Special Paving. Where landscape is required, it shall conform to Section 5.5 of these standards. E.Furnishing Zone This standard addresses furnishing within front Setbacks. F. Additional Standards and Guidelines These standards provide additional direction in shaping the appropriate building -to -street relationship. They address glazing at the ground floor, Frontages, and entries. 55 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES o FRONTAGE TYPE MATRIX Table 4-1: Frontage Type Matrix Frontage Type Shopfronts Typical Setback from Curb Entry Elevation Public Interface Direct access to Typical Use Retail,Food and Street Activation Section in Mixed -Use 15-25ft At Grade retail/commercial Beverage mixed- High 4.3 space Setback Buildings Area is Paved use Retail,Food and Paved Terrace. Beverage Mixed - Raised Direct access from use, where Commercial 20-25ft 1.5-4ft sidewalk to Ter- grading requires Moderate 4.4 Terrace race is optional ground floor spaces to be raised Raised Setback Area is Townhouses, Stoop 12-27ft 1-1/2 - 5ft Landscaped duplexes, apart- Moderate 4.5 ments Small landscaped At Grade or paved Setback Townhouses, Dooryard 20-30ft or Slightly defined by low duplexes and Moderate 4.6 Raised wall, hedge, or Walkups fence Setback area is Landscaped. Raised Porch is paved and Townhouses, Moderate/ Front Porch 18-28ft 1-1/2 - 5ft covered. Direct duplexes and High 4.7 access from side- Walkups walk to Terrace is optional Recessed court, often shared, At Grade- Courtyard may be Forecourt 12-20ft 2ft paved and/or land- Apartments High 4.8 scaped. Setback area may be paved or landscaped Raised Residential 15-25ft 1.5-4ft or land Multifamily, Moderate 4.9 soaped pl soaped platform adaptive reuse Terrace Non-retail or residential Urban At Grade Paved or Land- ground floor, Frontage 15-25ft or Slightly scape in Setback (e.g., hotels, Low 4.10 Raised area from sidewalk lobbies, office space, places of assembly, etc) Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 56 FRONTAGE TYPES • SHOPFRONTS IN MIXED -USE BUILDINGS 4.3 Shopfronts in Mixed -Use Buildings A. Intent Statement Shopfront Frontages provide direct access to ground - floor spaces that are located adjacent to the sidewalk. Shopfronts are typically associated with retail uses in addition to food and beverage, but may accommodate other uses as permitted by the Development Code. Where permitted, Shopfront Frontages may provide outdoor seating areas or outdoor displays or both. B. Entries Entries shall be set at the adjacent sidewalk or within an alcove that is adjacent to a sidewalk. C. Dimensions Shopfronts shall be between 12 and 22 feet high, measured from the finished floor to the bottom of ceiling of the storefront space. Storefront spaces shall be set no more than 12 inches above the adjacent sidewalk at the Primary Entrance. 2. Building Faces shall be set back from the curb a minimum of 15 feet and a maximum of 25 feet. If a Shopfront fronts a paseo, no Setback is required. D. Paving and Landscaping The Setback area between the property line and the Building Face shall be paved with Special Paving. Figure 4-1 - Shopfronts in Mixed -Use Buildings Illustrative Photo E. Furnishing Zone Furnishing Zones shall be in conformance with DBCC Section 22.42.080 and Sections 5.3 and 5.4 of this document. Notwithstanding the statement above, outdoor seating may be provided in front Setbacks, where permitted. Product displays (e.g. flowers, food, merchandise displays) are encouraged near Shopfront entries. 3 shall be 0 Property Line Figure 4-2 - Shopfronts in Mixed -Use Buildings Conceptual Plan -Property Line Figure 4-3 - Shopfronts in Mixed -Use Buildings Illustrative Section Ground floor uses open directly to the sidewalk. 57 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES • RAISED COMMERCIAL TERRACE IN MIXED -USE BUILDINGS 4.4 Raised Commercial Terrace in Mixed - Use Buildings A. Intent Statement Raised Terraces provide outdoor dining and seating for ground floor commercial uses. They are to accommodate grade changes between the adjacent sidewalk and the finished floor. Raised commercial Terraces are appropriate Frontages for mixed -use buildings on sloping sites. Terraces may be accessed from the sidewalk, but this is optional. B. Entries Terraces may be accessed from the building or directly from the adjacent sidewalk. C. Dimensions 1. Terraces may be raised up to four feet above the adjacent sidewalk. 2. Terraces shall be at least seven feet deep. 3. Terrace fronts shall be Setback from the curb a minimum of 13 feet. 4. Building Faces shall be set back from the curb a minimum of 20 feet and a maximum of 25 feet. D. Paving and Landscaping Terraces shall be paved. Figure 4-4 - Raised Commercial Terrace Illustrative Photo E. Furnishing Zone Where permitted, outdoor seating may be provided in front -Setbacks. Product displays (e.g. flowers, food, merchandise displays) are permitted near storefront entries. F. Additional Standards 1. Terraces shall be clearly delineated with permeable fencing, low walls or landscaping no higher than 42 inches. 2. The bottom of Awnings, Signs, etc. shall be located at least 10 feet above the Terrace. Sidewalk, grace Front -Property Line Figure 4-5 - Raised Commercial Terrace Conceptual Plan 1 110, M 1 4' Max. Property Line Figure 4-6 - Raised Commercial Terrace Illustrative Section Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 58 DIAMOND BAR FRONTAGE TYPES • STOOP 4.5 Stoop A. Intent Statement Stoops are small staircases leading to the entrance of a building. The Stoop elevation provides some privacy between the sidewalk and ground -floor uses. Stoops may be covered. B. Entries Entries fronting on public streets shall face the public sidewalk. C. Dimensions 1. Stoops shall be at least four feet deep and four feet wide. 2. The top of the Stoop (the landing) shall not be raised more than five feet above the adjacent sidewalk. 3. Walls, fences or landscape surrounding yards adjacent to the Stoop shall be no taller than 42 inches in Height. 4. Building Faces shall be set back from the curb a minimum of 17 feet and a maximum of 25 feet. D. Paving and Landscaping 1. Setback Area shall be planted with shrubs, or other drought tolerant ground cover. 2. Walks shall be paved with concrete or Special Paving. Figure 4-7 - Stoop Illustrative Photo 3. Low retaining walls, fences, or hedges may enclose a Dooryard. Walls and hedges shall not exceed 42 inches in Height measured from the adjacent sidewalk. E.Furnishing Zone Not permitted. F. Additional Standards 2 Stoops may encroach into any required Front Yard Setbacks, but not into public right-of-way or into any public utility easement. Awnings, canopies, and shed roofs may cover Stoops. Sidewalk Property Line j� f Setback Area shall be landscaped • i_ Figure 4-8 - Stoop Conceptual Plan Property Line Figure 4-9 - Stoop Illustrative Section The entry to a building is raised above the sidewalk. 59 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES • DOORYARD 4.6 Dooryard A. Intent Statement Dooryard Frontages provide a green buffer for residential ground -floor uses at heavily -trafficked thoroughfares. The Dooryard Frontages provide privacy. B. Entries 1. 1. Entries shall be recessed behind optional fence and/or hedges. There shall be a break for pedestrian access at least every 200 feet but can be frequent, if serving Townhouses. 2. Townhouses shall have entries serving the pedestrian accessible directly from the street. 3. Ground -floor units in multifamily buildings with corridors may have the primary entry from a corridor accessible from a common building lobby, directly from the sidewalk via a Dooryard, or both. C. Dimensions 1. Fence, hedges or walls shall be no taller than 42 inches measured from the Sidewalk Grade. 2. Dooryards shall be 10-15 feeet in depth. 3. Building Faces shall be set back from the curb a minimum of 20 feet and a maximum of 30 feet. D. Paving and Landscaping Figure 4-10 - Dooryard Illustrative Photo 1. The Setback Area shall be paved or landscaped. 2. Walks shall be paved. E. Furnishing Zone Outdoor furniture is permitted in the Dooryard but not in the Setback Area. F. Additional Standards 1. If used, hedge shall be thick enough at maturity to obscure the fence. 2. Fence tops shall not be visible above hedge upon maturation of landscaping. Figure 4-11 - Dooryard Conceptual Plan JT42" Max. �~ Property Line Figure 4-12 - Dooryard Illustrative Section Ak Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 60 DIAMOND BAR FRONTAGE TYPES • FRONT PORCH 4.7 Front Porch A. Intent Statement A roofed, unenclosed room attached to the exterior of a building that provides a physical transition between the sidewalk and the building. Porches may be provided on buildings that are set back from the primary and/or side street property lines and may encroach into the Front Yard and side street yard pursuant to DBCC Section 22.16.090 (3)(c). B. Entries Porches may be accessed directly from the adjacent sidewalk along the primary and/or side street. C. Dimensions 1. Porches shall be a minimum of six feet in depth. 2. The face of porch may be set back from the property line up to 15 feet maximum. 3. Ceiling Height on porches shall be a minimum of eight feet. 4. Where porches are set back from the Frontage line by at least 10 feet, the space between the face of the porch and the Frontage line (yard) may be enclosed by a fence, hedge or wall of a Height no greater than 42 inches above finished grade. 5. Building Faces shall be set back from the curb a maximum of 28 feet. D. Paving and Landscaping Figure 4-13 - Front Porch Illustrative Photo 1. The Setback Area between the property line and the building front shall be landscaped. 2. Walks shall be paved. E. Furnishing Zone Not applicable. F. Additional Standards 1. Porch materials and design shall be of the same Architectural Style as the rest of the building. 2 Porches may be enclosed with insect screens, provided they are recessed from the exterior wall plane and if visibility is maintained from the ciriawalk i Property Line Figure 4-14 - Front Porch Conceptual Plan rropercy une----w rviaa• o Figure 4-15 - Front Porch Illustrative Section 61 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES • FORECOURT 4.8 Forecourt A. Intent Statement E. Furnishing Zone Forecourts are open areas located at primary building 1. The courtyard may include benches, chairs, entrances. They may be designed as gardens or as tables, Planters and pots. paved courtyards. Frontages utilizing a Forecourt must 2 Water Features are permitted. comply with Minimum Frontage Occupancy standards. B. Entries Ground -floor units in multifamily buildings with a Forecourt shall enter from the adjacent sidewalk. Building entries opening onto the Forecourt shall be at the finished floor of the Forecourt or may be raised up to three feet above the Forecourt. C. Dimensions 1. Forecourts shall be set at grade or may be elevated up to two feet above the adjacent sidewalk. 2. Width of the Forecourt shall be between 30 and 50 feet. 3. Depth of the Forecourt shall be minimum 10 feet. 4. Building Faces shall be set back from the curb a minimum of 12 feet and a maximum of 20 feet. D. Paving and Landscaping 1. Forecourts may be planted with grass, shrubs, or other ground cover or be paved. Special paving shall be provided for all walks. 2. Setback areas shall be landscaped. Figure 4-16 - Forecourt Illustrative Photo F. Additional Standards 1. Forecourts shall be open to the sky. Porches are permitted as long as the minimum 30 feet width is maintained. 2. Forecourts may be gated. If gated, the standards for gates shall be in conformance with the Development Code. =, Property Line Figure 4-17 - Forecourt Conceptual Plan Property Line Figure 4-18 - Forecourt Illustrative Section The building entry is located off a Forecourt. The entry may or may not be raised above the sidewalk level. Akl Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 62 DIAMOND BAR FRONTAGE TYPES • RAISED RESIDENTIAL TERRACE 4.9 Raised Residential Terrace A. Intent Statement An elevated Terrace separates and sets back the Fagade from the sidewalk and street. This type buffers residential use from urban sidewalks and removes the private yard from public Encroachment. Terraces are also useful to accommodate grade changes in the topography. B. Entries Terraces may be accessed from the building or directly from the adjacent sidewalk. C. Dimensions 1. The front of Terrace may be at a maximum two feet behind the property line. 2. Terraces may be elevated up to four feet above the adjacent sidewalk. 3. Where the Height of Terrace requires a rail or wall that Height shall not exceed the minimum Height established by the Building Code. 4. Terraces shall be at least seven feet deep and Setback 20-25 feet. Figure 4-19 - Raised Residential Terrace Illustrative Photo D. Paving and Landscaping 1. Setback Area fronting Raised Residential Terrace shall be landscaped. 2. Raised Terraces may include paving and/or landscape. E. Furnishing Zone The raised Terrace may be furnished. F. Additional Standards None. Sidewalk Setback Area ?rrace Front Line Figure 4-20 - Raised Residential Terrace Conceptual Plan L- 4 Terrace Front 4' Max. Property Line2' Max. Figure 4-21 - Raised Residential Terrace Illustrative Section 63 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development FRONTAGE TYPES • URBAN FRONTAGE 4.10 Urban Frontage A. Intent Statement An urban Frontage is suitable for residential lobbies or commercial/office uses. It may provide access to ground- floor uses, but is primarily characterized by windows facing the sidewalk. Unlike storefronts, there is no minimum ground floor Height. Nor is there a requirement for individual entries to individual shops, offices or other spaces that constitute the Frontage. B. Entries 1. Urban Frontages shall provide primary pedestrian access directly from the sidewalk to a lobby and need not provide entrances to individual shops or spaces like a Shopfront. 2. Primary pedestrian access shall be visually emphasized through the use of canopies, awnings or fixed overhead architectural Projections such as porticos. C. Dimensions 1. Urban Frontages shall be set at grade or may be elevated up to 12 inches above the adjacent sidewalk. 2. Building Faces shall be set back from the curb a minimum of 15 feet and a maximum of 25 feet. Figure 4-22 - Urban Frontage Illustrative Photo D. Paving and Landscaping 1. Urban Frontages are characterized by Hardscape and/or landscape within the Setback area. E. Furnishing Zone Where permitted, outdoor seating may be provided in front Setbacks. Low growing landscape is also permitted to provide privacy for activities taking place in building's ground -floor space. F. Additional Standards None. Property Line Area al Lobby or mercial Uses Figure 4-23- Urban Frontage Conceptual Plan Property Line Figure 4-24 - Urban Frontage Illustrative Section An urban Frontage Type for residential or commercial ground -floor uses. Akl Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 64 DIAMOND BAR SITE AND OPEN SPACE STT'IDARDS Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development SITE AND OPEN SPACE STANDARDS • STANDARDS AND GUIDELINES SITE AND OPEN SPACE STANDARDS 5.1 Purpose and Intent The architectural standards in this section apply to all multifamily residential and mixed -use developments in Diamond Bar. They address the composition of buildings as well as functional aspects of building, parking, and outdoor space design. The goal of this section is to ensure that development is consistent with the goal of creating a human -scale mixed -use environment in which each individual building furthers the overall vision. The images in this section are for Illustrative purposes, only provided to illustrate intent. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 66 SITE AND OPEN SPACE STANDARDS • GRADING STANDARDS 5.2 Grading Standards 5.2.1 Applicability The Standards of this section shall apply to mixed - use parcels only. They address the setting of ground floor elevations to ensure accessibility and a seamless Connection between the streets and spaces of the plan area, and the ground floor of commercial offerings. 5.2.2 Standards The finished floor elevations of buildings, shall be set in accordance with the following criteria: 1. The finished floor elevation of primary building entrances and storefront entrances shall be set to meet existing (as designed) street grade. This may require the stepping of the building floor plate. 2.Cross and longitudinal slopes of up to five percent are allowed in any front Setback areas subject to ADA access requirements, however, areas abutting storefront Frontages shall not exceed two percent. 3. Notwithstanding 5.2.2.1 and 5.2.2.2 above, the following grading strategies may also be employed, where necessary: • The cross slope of the tree zone may be increased to a maximum of five percent. • Sidewalk cross slope may be decreased to a minimum one percent provided that adequate drainage is demonstrated. • The longitudinal slope of the public sidewalk may be increased to exceed that of the adjacent public street by a maximum of three percent. • The Terrace Frontage may be utilized (See Figure 5-1 and Section 4.9). 4.In order to ensure that transitions between sidewalks and storefronts are as seamless as possible, steps, ramps, and retaining walls solely associated with building ingress and egress are prohibited in the Front Yard except where it is required for grading purposes. In such cases a Terrace Frontage shall be utilized (See Section 4.9). Figure 5-1 - Illustrative Photo of Terrace Frontage 67 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development SITE AND OPEN SPACE STANDARDS • EXTERIOR LIGHTING & OUTDOOR SEATING AREAS, CAFES, AND RESTAU- RANTS IN MIXED -USE ZONES 5.3 Outdoor Seating Areas, Cafes, and Restaurants in Mixed -Use Zones Outdoor seating areas, cafes and restaurants in mixed - use zones shall be in conformance with DBCC Section 22.42.080(3). Notwithstanding the statement above, the following standards are also applicable: 1. Outdoor seating areas, cafes, and restaurants on private property, as part of mixed -use development shall not interfere with pedestrian flow and circulation along adjacent sidewalks, from public ways to building entries, or with amenities, such as bicycle racks and benches. Figure 5-2 - Illustrative Photo showing outdoor seating areas, cafes and restaurants in mixed use conditions 5.4 Outdoor Furnishings Visible from ROWS Applicable to Mixed -Use Zones 1. The following materials shall be used for furnishings in private spaces that are visible from public ROWS. a. Benches, chairs and tables shall be made of be made of wood, metal, stone, concrete, recycled High -Density Polyethylene (HDPE), or a composite of wood and plastic (recycled HDPE) composite. b. Trash cans and bike racks shall be made of metal. c. Planters and pots shall be made of metal, stone, terra cotta, cast stone, cast concrete, hand -sculpted concrete, or composite material that resemble wood. d. Moveable furnishings such as tables and chairs shall not be stored in a location that is visible from the street. Figure 5-3 - Illustrative Photo showing street furnishings in mixed -use conditions Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 68 SITE AND OPEN SPACE STANDARDS LANDSCAPE STANDARDS 5.5 Landscape Standards Landscape design standards, including standards for street trees and parkways, shall be in conformance with DBCC Chapters 22.24, 22.26 and Section 21.30.070. Notwithstanding the statement above, the following standards are also applicable in all areas covered by these Objective Design Standards. Street tree spacing shall be between twenty-five and forty-five feet (30'-0" and 50'-0") on center with adjustments in spacing pursuant to Public Works Department standards. Plants shall be arranged with the tallest shrubs located at base of buildings and structures, transitioning to lower shrubs adjacent to sidewalks and curbs. A minimum of two Heights or tiers shall be provided (e.g., low planting and taller planting adjacent to the wall). (See Figure 5-4A for dimensions of each tier) 3. For landscape areas greater than ten feet wide, provide a minimum of three tier levels (e.g., groundcover or annuals, low planting and tall planting adjacent to the wall). (See Figure 5-413 for dimensions of each tier) Tall Tier: 3'-0" to 4'-0" High Foundation and Flowering Shrubs Low Tier: 1'-6" to 2'-6" High Perennials and Groundcover Parkway: Less than 24" High Foot traffic tolerant Low Perennials and Groundcover Figure 5-4A - Two Tiers of Planting Tall Tier: 3'-0" to 4'-0" High Foundation and Flowering Shrubs Mid -Level Tier: 2'-0" to 2'-8" High Flowering and Annual Shrubs Low Tier: 1'-6" to 2'-6" High Perennials and Groundcover Parkway: Less than 24" High Foot traffic tolerant Low Perennials and Groundcover Figure 5-413 - Three Tiers of Planting 69 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development SITE AND OPEN SPACE STANDARDS • COMMON OPEN SPACE & INTERIOR COURTYARDS 5.6 Common Open Space Common Open Space standards shall be in conformance with DBCC Sections 21.30.070, 22.26.040 and 22.26.050. Notwithstanding the statement above, the following standards is also applicable in all areas covered by these Objective Design Standards. Artificial trees, shrubs, turf and plants shall not be used as landscape within the public right of way, any parking area, or within an open space area directly visible to from the public right of way. 2. Outdoor dining areas shall have concrete to match the adjacent sidewalk, or special pavers, and/or a row of Planters or bollards, or permeable fence to delineate the dining space. 3. Benches, chairs and tables shall be made of be made of wood, metal, stone, concrete, recycled High -Density Polyethylene (HDPE), or a composite of wood and plastic (recycled HDPE) composite. 4. Planters and pots shall be made of metal, stone, terra Gotta, cast stone, cast concrete, hand - sculpted concrete, or composite material that resemble wood. Figure 5-5 - Common Open Space Illustrative Photo Outdoor dining area divided from public walking space with railings. 5.7 Interior Courtyards Required outdoor space may be accommodated in interior courtyards located on the ground plain or on a Podium, as allowed by the relevant Building Type (see Chapter 2). When provided, interior courtyards shall adhere to the following standards: 1. Shade Trees. Interior courtyard landscaping shall include shade trees or shading devices. At least one 3-inch caliper specimen tree is required per 1,000 square feet of courtyard area. 2. Dimensions. Minimum courtyard dimension on any side shall be 30 feet (exclusive of Encroachments) unless indicated otherwise in the Building Types. 3. Blank Walls. Where courtyards are visible from the Principal Frontage, Blank Walls shall not be permitted inside the perimeter of the courtyard. Alternatively, courtyards shall include windows, doors, balconies and/or shall be screened with landscape, such that the landscape covers at least 2/3 of the Blank Wall. F'= Figure 5-6 - Interior Courtyard Illustrative Photo Landscape and Hardscape create intimate spaces in this courtyard. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 70 SITE AND OPEN SPACE STANDARDS • FENCES, HEDGES AND WALLS & RETAINING WALLS 5.8 Fences, Hedges and Walls Garden walls, retaining walls, hedges and fences may be used to define the edge between adjoining private properties. Fences, hedges and walls facing the public street shall also comply with the Frontage Type standards (see Chapter 4). Fences, hedges and walls standards shall be in conformance with DBCC Chapter 22.20. Notwithstanding the statement above, the following standards are also applicable in all areas covered by these Objective Design Standards. 1. Location. Garden walls, retaining walls, hedges and fences shall be built at least 18 inches from the property line, to allow room for footings and planting. 2. At Storefronts. Walls and fences shall not be used at storefronts or storefront cafes, except that retaining walls shall be permitted in situations where they are necessary to accommodate grade changes. 3. Plastic and Vinyl. No plastic or vinyl fencing shall be permitted forward of the Build -to Line, unless the material is a recycled plastic lumber (RPL). 4. Vegetation utilized as hedges adjacent to public sidewalks or paseos shall not be of the type that produces thorns or spines (e.g., blackberries, rose bushes, or cacti, among others). Figure 5-7 - Hedge Screening Service Area A hedge and other plantings effectively screens a service area from view. 5.9 Retaining Walls Retaining wall standards shall be in conformance with DBCC Chapter 22.20, except that unfinished concrete block and interlocking concrete pavers (such as keystone) shall not be used as retaining walls when visible from the street. 71 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development SITE AND OPEN SPACE STANDARDS • VEHICULAR PARKING, LOADING AREAS & BICYCLE PARKING STANDARDS 5.10 Vehicular Parking Vehicular parking standards shall be in conformance with DBCC Chapter 22.30. 5.10.1 Parking Location 1. Parking location shall be in conformance with the requirements of the particular Building Type to which is associated. (See Chapter 2) 2. At Block Fronts facing public streets, at -grade or above -ground parking that may be provided shall be screened by a habitable space no less than 20 feet deep. Subterranean parking may extend to the property line. 5.10.2 Parking Access 1. To the extent parking is provided, it shall be accessed from a public or private alley when present. If no alley is present, parking access shall be from the street consistent with DBCC Section 22.30.080. 2. Pedestrian entrances to all parking shall be directly from the street, except that underground parking garages may be entered directly from a building. 5.10.3 Parking Structures 1. All parking structure exits shall maintain a Clear Sight Triangle pursuant to Public Works Department standards to protect pedestrians from exiting vehicles. The triangle is placed with one point aligned with the driver's position. The opposite far edge of the triangle is then placed flush with the edge of the pedestrian pathway. 2. Pedestrian crossing signage shall be placed at all garage structure exits along with a stop bar set back from the edge of the pedestrian pathway. 5.11 Loading Areas Loading areas shall be in conformance with DBCC Section 22.30.100. Notwithstanding the statement above, the following standards are also applicable in mixed -use projects. 1. Service and loading areas shall be located away from public streets whenever possible. Entrances to loading areas shall be no more than 18 feet wide. 2. Entrances to loading areas fronting public streets shall be enclosed by an opaque gate covering the entire entrance. Chain link fencing is not permitted for use as a gate. 3. Loading areas must accommodate both trash and recycling. 4. Multifamily residential projects over 100 units shall designate space for moving truck loading and unloading. 5.12 Bicycle Parking Standards Bicycle parking standards shall be in conformance with DBCC Section 22.30.90. Notwithstanding the statement above, the following standards for short-term bicycle parking are applicable in mixed -use projects. Short-term bicycle parking is intended to offer a convenient and accessible area to park bicycles for customers and other visitors. 1. 10% of the multifamily bicycle parking shall be short-term that is, for building visitors who will use the space for two hours or less. 2. 90% of hotel bicycle parking shall be short- term. 3. 90% of eating and drinking establishments bicycle parking shall be short-term. 4. 80% of office and retail business bicycle parking shall be short-term. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 72 SITE AND OPEN SPACE STANDARDS • SERVICE AND AUXILIARY EQUIPMENT & EXTERIOR LIGHTING 5.13 Service and Auxiliary Equipment 5.14 Exterior Lighting Service and auxiliary equipment standards shall be Exterior Lighting shall be in conformance with DBCC in conformance with DBCC Sections 22.16.080 and Section 22.16.050 or the applicable Specific Plan. 22.16.100. 1. Service, utility, and mechanical functions, including retail loading, shall be located in alleys whenever present. When alleys are not present, service, utility and mechanical functions shall be placed behind buildings and provisions for access shall be made. 2. Service, utility, and mechanical equipment that is visible from the street shall be screened from view with landscaping or enclosures. Backflow preventers and fire standpipes, along with utility box transformers shall be screened. 3. All screening devices shall be of the same materials and colors of the building to which they are attached. Operable gates and decorative trim may differ in color and materiality. 4. Trash areas that are visible from public streets or adjacent properties shall be enclosed by walls. Trash area entrances shall be enclosed by a door. 5. Roof vent penetrations and mechanical equipment shall be located at least ten feet (10'- 0") from any exterior Building Face. Figure 5-8 - Service and Auxiliary Equipment Illustrative Photo Trash enclosures and utilities shall be screened from view. 73 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 74 ADCHITECTURAL ES 1 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • INTENT ARCHITECTURAL STYLES 6.1 Intent An architectural stylistic framework shall be the basis for establishing Objective Design Standards for all multi- family and mixed -use development. This framework honors the San Gabriel Valley's existing Architectural Styles by providing a regulatory framework to continue its eclectic architectural tradition. The following standards enable the significant characteristics of the following five Architectural Styles that have been identified as relevant. The five styles are identified below: • Main Street Commercial • Spanish Revival • Craftsman • Art Deco • California Contemporary The above styles are described in terms that assist the user of these standards to understand their historic precedence and prepare contemporary designs in these historic styles. Each style is described and differentiated from the others through nine criteria. These describe their prevalent language of composition, technique, materiality, and detail for the user to apply to new designs: massing, base, primary walls of upper floors, roof- wall transitions, roof, drainage, door and window openings, attached elements. Applicants for multifamily residential and mixed -use development (that includes housing) shall select and conform to one Architectural Style and one corresponding Building Type for each proposed building pursuant to the standards. If a development is proposing several buildings and/or Building Types, the applicant may provide different Architectural Style and Building Type combinations in the same development. Each style is described and differentiated from the others through nine building criteria as follows: 1. Applicability 2. Massing 3. Base and Ground Floor 4. Primary Walls of Upper Floors 5. Roof Wall Transitions 6. Roof 7. Drainage 8. Door and Window Opening 9. Attached Elements Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 76 ARCHITECTURAL STYLES • MAIN STREET COMMERCIAL Figure 6-1 - Main Street Commercial Illustrative Photo 6.2 Main Street Commercial The Main Street Commercial style is derived from the late nineteenth and early twentieth century mixed -use architecture that characterized the downtowns of small cities and towns throughout California. Buildings of this style are decorated rectangular masonry (or stucco) boxes in form and are typically mixed -use with commercial ground floors in terms of function. However, this style may also be used for buildings that are exclusively residential. Multi -Story Fagades are typically divided into base, middle and top, or "tri-partite", with the ground floor taller than the shorter upper floor which is finished by a significant Parapet. The ground floor has expansive glass interrupted by structural columns with transoms to allow light to penetrate deep into the interior. Upper -level windows are typically punched openings, often grouped in twos or threes by piers, pilasters, or other Fagade elements, creating a repetitive bay structure directly relating to the ground floor openings. A. Applicability 1. This style is applicable to mixed -use zones only. Not oil i11 111 KIr Figure 6-2 - Main Street Commercial Illustrative Photo 77 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • MAIN STREET COMMERCIAL B. Massing 1. Main Street Commercial buldings shall present Frontages that are square or simple rectangles and as a single Volume. 2. Notwithstanding this requirement, no greater than 10 percent of the total Frontage may include deviations to the rectangular forms, through changes in Height, Setback or Encroachment, or corner articulation. See Figure 6-3. C. Base and Ground Floor 1. An explicit base level element shall ground the Figure 6-3 - Rectangular Form building up to two feet six inches maximum Percentage Diagram Height, such as a bulkhead, footer, or sill. 2.The ground floor base shall provide a minimum of one -foot -wide horizontal band of a different plane on the Fagade at the top of the first Story, such as a Cornice or lintel. 3. Exterior wall materials shall be applied as a horizontal band of brick, stone, cast concrete, stucco, terra Gotta, or cementitious fiberboard. D. Primary Walls of Upper Floors 1. Upper floor walls shall be expressed as single -plane expanse of cast concrete brick, stucco and plaster materials, terra cotta or cementitious fiberboard siding. Notwithstanding that, nothing in this statement shall be interpreted as prohibiting the inclusion of Decorative Detail on the surface or that is additive in nature. 2.Where present, attached building wall elements, such as awnings and balconies, shall encroach into the building's Setbacks. 3. Window shutters shall not be allowed. E. Roof -Wall Transitions 1. Exterior walls shall transition directly into roof Parapets or into plaster molding or Cornice line forms. 2.For buildings with flat roofs, exterior Parapets shall be articulated as a continuation of the exterior wall and shall include a Cornice or Decorative Detail on the surface of the Parapet. Figure 6-5 - Decorative Brick Figure 6-7 - Cornice Figure 6-4 - Large Windows Ground Floor Figure 6-6 - Single Plane Figure 6-8 - Parapet and Cornice Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 78 DIAMOND BAR ARCHITECTURAL STYLES • MAIN STREET COMMERCIAL F. Roof 1. For buildings with pitched roofs greater than 6:12, roofs shall overhang the wall surfaces by a minimum of two feet. G. Drainage 1. Where a rain drainage catchment is visible, (i.e., not embedded within the building's walls) it shall be conducted with a combination of gutters and downspouts fabricated either from untreated copper or painted metal to contrast with the Building Face. H. Door and Window Openings 1. Ground floor Fenestration shall conform with the requirements for the appropriate Frontage (see Chapter 4). 2.Transoms above doorways are required on the ground floor. 3. Upper floor windows and doors shall have a square or vertically oriented rectangular shape. This requirement does not preclude the use of arches or articulated lintels atop the openings. 4.Door and window openings shall be centered on the spaces between the pattern of ground floor columns and piers. 5.Windows on upper floors shall appear to be "punched" by recessing them from the surface by a minimum of two inches. Where windows are arranged in groups of two or three, the entire group shall be recessed from the outer surface. 6.Door and window openings on the Upper Floors of Primary Frontages shall constitute a minimum of 33 percent of the Fagade. This requirement may be reduced to 20 percent if windows and doors are recessed at least four inches from the surface of the Facade. 7. Windows on the upper floors shall be double -hung or awninn tvne_ I. Attached Elements 1. Awnings, canopies, and upper floor balconies or bay windows are subject to Encroachment requirements, See DBCC Section 22.16.090 (3) and Section 3.8 of this document. Oki Figure 6-9 - Awnings at Commercial Frontage Figure 6-10 - Canopy Frontage ARCHITECTURAL STYLES • MAIN STREET COMMERCIAL Roof and Eaves Flat roof with Parapet or projecting molding and Cornice lines. Windows Upper floor windows align with ground floor windows, doors, and piers or column patterns. Walls Flat planes of brick, stone, cast concrete, stucco, and plaster materials. Extend into the public right-of-way. If Setback, shall refer to Section 22.16.090(3) of DBCC. Cornice or Lintel The ground floor base shall provide a horizontal band of a different plane on the Faqade at the top of the first Story. Shopfront Transoms and piers articulate doors and windows. Base Shopfront base grounded with a sill or a Tooter. Figure 6-12 - Main Street Commercial Elements Diagram (Ground Floor Commercial) Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 80 DIAMOND BAR ARCHITECTURAL STYLES • MAIN STREET COMMERCIAL Roof and Eaves Flat roof with Parapet or projecting molding and Cornice lines. Windows Upper floor windows align with ground floor windows, doors, and piers or column patterns. Walls Flat planes of brick, stone, cast concrete, stucco, and plaster materials. Extend into the public right-of-way. If Setback, shall refer to Section 22.16.090(3) of DBCC. Cornice or Lintel The ground floor base shall provide a horizontal band of a different plane on the Fagade at the 1 top of the first Story. Base Residential entrance with a Stoop Figure 6-13 - Main Street Commercial Elements Diagram (Ground Floor Residential) 81 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 82 DIAMOND BAR ARCHITECTURAL STYLES e SPANISH REVIVAL %JI Figure 6-14 - Spanish Revival Illustrative Photo 6.3 Spanish Revival Spanish Revival architecture draws from the adobe structures of the California Missions, which were prominently showcased in the California Pavilion at the 1893 World's Columbian Exposition. The style was subsequently adopted by several railroad companies for train stations and hotels, and it soon became a defining architectural language across California, used extensively in both institutional and residential settings. The style is characterized by thick-walled massing, often expressed through deeply recessed openings and arcades. Emulating this depth —particularly in features such as arcades — is essential to achieving an authentic expression of the style. Spanish Revival, including the Mission subtype, represents a mature and complex architectural tradition that evokes a strong sense of urban character and an intimate relationship with the natural environment. Key features include white or light-colored stucco walls, sloped red clay tile roofs with exposed rafter tails, shaped Parapets, and generous balconies —often detailed with ornamental metal railings. Fagade Compositions may be either symmetrical or asymmetrical, but window sizes, locations, and alignments are typically varied. Arched openings are common, appearing unframed in upper -Story windows or as part of ground -floor arcades at entries or along Frontages facing Public Spaces. I IV Figure 6-15 - Spanish Revival Illustrative Photo 83 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • SPANISH REVIVAL A. Applicability 1. This style is applicable to all mixed -use and multifamily zones. B. Massing 1. Volumetric composition shall be with a primary Volume accounting for at least 60 percent of the Frontage, but no more than 90 percent offset by a variety of lesser Volumes See Figure 6-16. C. Base and Ground Floor 1. While not required, if an articulated base element is applied on the Ground Plane, such as a footer, it shall be no taller than three feet maximum Height from grade. 2.Where utilized, the base element shall be one of the following: a.A horizontal band painted with the darkest accent color applied to the building Fagade. b.A horizontal band painted the exact same color as the entire building Fagade. c. A horizontal band of ceramic tile, plaster, stone or cast concrete materials D. Primary Walls of Upper Floors 1. Primary Upper floor walls of the primary Volume shall be expressed as a single -plane expanse of stucco or plaster surface, smooth or hand -troweled textures. Primary Walls of secondary Volumes shall be surfaced in stucco or plaster. 2.Notwithstanding the requirement above, materials such as decorative tile, ornamental metal, stone, or terra cotta may recess within the wall, set flush with the surface of the wall or in the case of traditional moldings, be applied atop the surface. Stone or cast concrete materials shall not be allowed above the ground floor base element, except for attached chimneys, unless the material is a continuation of the identical material used below. E. Roof -Wall Transitions 1. Where a Parapet is used at the roof line, it shall include at least one of the following elements to establish a visible termination of the wall plane: n I A B � A>_ 60%(A+B) <_ 90%(A+B) �. Figure 6-16 - Volumetric Figure 6-17 - Painted Base with Composition Diagram Recess W_ I Figure 6-18 - Single Plane Composition 11rr. �c in Figure 6-20 - Parapet with Flat Roof Figure 6-19 - Balcony Overextending Sidewalk Figure 6-21 - Clay Tile with No Eave Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 84 ARCHITECTURAL STYLES • SPANISH REVIVAL a. A shaped or stepped Parapet profile (e.g., curvilinear, sloped, or crenellated). b.A coping element with a contrasting material, texture, or Projection of at least two inches from the wall surface. c. A plaster molding, Cornice band, or cap that projects a minimum of two inches and extends continuously along the Parapet edge. Flat, unadorned Parapets without variation in form or detailing are prohibited. All Parapet profiles shall be consistent with historical Spanish revival precedents, such as Mission -shaped curves. 2. Exterior walls shall transition into roof form by one of three devices: a. A projected wooden Eave with exposed wooden rafters; b. Plaster molding; or c. A tile cap. 3. Foam moldings are permitted only on the second (2nd) floor or above and shall not be used in occupied or high -use areas such as doorway trim or facing balconies. F. Roof 1. Gabled or hipped roofs shall be low-pitched at a 3:12 minimum to 5:12 maximum ratio and finished in clay or concrete barrel or S-tile. 2.Flat roofs are allowed and shall be articulated as an explicit exterior surface (tile may be multi -color randomly placed) visual transition to the sky. May be accessible and used as balconies or Terraces. 3. Overhanging downslope Eaves shall be a minimum of 16 inches wide supported by wooden rafter tails and exposed Eaves or metal brackets. G. Drainage 1. Rain drainage catchment shall be conducted with a combination of half -round gutters and round downspouts entirely in dark painted metal or untreated copper and shall be located within six inches of building corners. H. Door and Window Openings 1. Window on Primary Fagades shall be punched openings with no surround and deep-set with a minimum two-inch plaster return. 2.Window and opening compositions shall only utilize the following shapes: • Square; • Vertically proportioned rectangles (Height greater than width); • Arched top forms, including full, segmental, or eyebrow arches; • Circular or oval; • Quatrefoil, trefoil, or other symmetrical ornamental forms, each not exceeding 36 inches in width, and used only as accent openings. Horizontally proportioned openings (width greater than Height) are prohibited, except when used as small vents or decorative accents not exceeding 24 inches in width. 3.Shutters shall be the aggregate size of the associated opening. 4.Operable windows on upper floor shall be casement or single hung. 5.Sliding doors are not permitted unless they have a minimum stile width of four inches. 6.Ground floor Fenestration shall conform with the requirements for Shopfronts. (See Section 4.3). 7. Upper floor windows and doors shall be geometrically square or rectilinear oriented with the longer dimension running vertically. Notwithstanding this, nothing in this requirement shall preclude the use of arches or articulated lintels atop the openings. 8.Door and window openings shall be centered on the spaces between the pattern of ground floor columns and piers. 9.Doors and Windows openings on upper floors shall appear to be "punched" by recessing them from the surface by a minimum of two inches. Where windows are arranged in groups of two or three, the entire group shall be recessed from the outer surface. 10.Door and window openings in the Upper Floors of Primary Frontages shall constitute a minimun of 33 percent of the Fagade. This requirement may be reduced to 20 percent if the windows and doors are recessed a minimum of four inches. I. Attached Elements 1. Awnings, canopies, and upper floor balconies or bay windows are subject to Encroachment requirements. (See DBCC Section 22.16.090(3) and Section 3.8 of this document.) 2.Balconies shall be supported by bracketing entirely in metal or exposed wood. 3. Bay windows shall be supported in wooden brackets or exposed joist extensions. 85 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • SPANISH REVIVAL Balconies Supported by metal brackets. Vertical Architectural Elements Include chimney, belvedere, covered patio and Terrace. Flat or Low Pitch Roofs If a pitched roof, gables with barrel tile and exposed Eaves and hipped with exposed Eaves. If a flat Parapet, the exterior wall transitions to the sky. <� Shallow Eaves Overhanging downslope Eaves supported by wooden rafter tails and exposed Eaves or metal brackets. Windows Recessed square or rectangle shape. Walls ■ A single -plane of stucco or plaster. 11111111111 Base Articulated Tooter is optional. ILHU_ !ICI Figure 6-22 - Spanish Revival Elements Diagram Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 86 DIAMOND BAR ARCHITECTURAL STYLES • CRAFTSMAN _ 'MR Figure 6-23 - Craftsman Illustrative Photo 6.4 Craftsman The English Arts and Crafts movement of the mid- to late-19th century inspired the Craftsman architecture of California. It was invented as a style of the handmade and earthy, a reaction to the repetitiveness and homogenization of the industrial culture emerging at the time. The Arts and Crafts movement became the expression of choice for an unadorned, popular, and natural architecture. Good examples of Craftsman buildings for larger scaled three to five Story buildings can be found in historical hotels, California courtyard multifamily housing and mountain / national park resorts. In its most simple form, it is a wood box surrounded by various attached elements, such as roof dormers or expressive downspouts. Walls are typically horizontally placed wood siding, shingles, or board -and -batten (often in a combination of two or three) with a foundation base and piers in stone, brick or stucco. A large gable shallow sloped roof with dormers to break up massing is typical. Dormers may feature shed or flat roofs and can have gable ends. Rafter tails, decorative brackets, and porch columns are exposed, smooth, woodwork. Windows and doors are vertical in proportion, trimmed in wood. Roofs are clad in wood or shingles with broad overhangs and Eaves. A. Applicability 1. This style is applicable to all mixed -use and multifamily zones. Figure 6-24 - Craftsman Illustrative Photo 87 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES @ CRAFTSMAN B. Massing 1. Volumetric composition shall be with a primary Volume accounting for at least 60% of the Frontage, but no more than 90% offset by a variety of lesser Volumes. 2.At least 70 percent of the top floor shall be subsumed in the roof with dormers. In buildings with varying Heights, this requirement shall apply to the top floor in each section of the building. 3. Dormers may have shed or flat roofs, or gable ends. C. Base and Ground Floor 1. An explicit base element shall be applied at the Ground Plane, and it shall be measured up to one to three feet in Height and expressed as horizontal band/Layer pattern and made of brick, stone, stucco, or shingle materials. 2.Ground floor shall be differentiated in terms of materials and/or color from upper floors. 3. Piers shall be a minimum of 6"x6" if wood posts, and 18"x18" if stone or stucco. D. Primary Walls of Upper Floors 1. Masonry materials, such as brick, stone or stucco shall not be allowed above the ground floor base element, except for attached chimneys. 2.Upper floor exterior walls shall be clad primarily (up to 90 percent of a vertical Fagade section) as single -plane expanse of wood, shingle, shake, or clapboard siding up to the roof line. with a secondary material utilized from 10-30 percent of any vertical section). Secondary materials can be defined by a change in color, a change in size or pattern of the shingles or shakes, or a completely different material. 3. The space between columns and piers shall be either square or vertically rectangle shape with a Height to width proportion ratio of no more than 3:1. See Figure 6-29. 4.Door and window openings shall be centered on the spaces between columns/piers below. 5.Piers shall be a minimum of 6"x6" if wood posts. Figure 6-25 - Masonry and Stone Figure 6-26 - Gutter and Base Downspout Figure 6-27 - Paired Openings Composed Horizontally Figure 6-28 - Painted Shingles Over Siding -- - �r/'J Figure 6-29 - Space Between Figure 6-30 - Craftsman Columns and Piers Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 88 DIAMOND BAR ARCHITECTURAL STYLES • CRAFTSMAN E. Roof -Wall Transitions 1. Exterior walls shall transition into roof form by projected wooden Eaves with exposed rafters. 2.Eaves shall have an overhang of at least three feet. F. Roof 1. Roofs shall be designed with a pitched gable or hipped roof. Principal gables are between 3:12 and 6:12, and shed slopes shall be less than the principal slope (between 2:12 and 4:12). 2.Eaves shall be supported by wood bracket details and exposed wood rafters to support gable end roofs. 3. Dormers, if used, shall have shed or gable ends. G. Drainage Rain drainage catchment shall be conducted with a combination of gutters and downspouts in entirely painted metal or untreated copper finishes. H. Door and Window Openings 1. Window lites may be divided into equal increments or be divided on a portion of a window (such as the upper portion of a double -hung or casement window). 2.Primary entry doors on the ground floor shall be made of wood or fiberglass that are made to resemble wood. 3. Window and opening compositions shall be either square and/or vertically rectangle shaped. However up to three windows may be grouped to form a horizontal opening. 4.One Specialty Window (neither square nor rectilinear) per vertical section, may be utilized. 5.Window shutters, if used, shall match the aggregate size and shape of the associated opening. 6.Door and window openings on the Upper Floors of Primary Frontages shall constitute a minimum of 25 percent of the Fagade. I. Attached Elements 1. Porches, chimneys, and trellises can encroach beyond the primary exterior surface of buildings and into their Setbacks. See DBCC Section 22.16.090(3). 2.Balconies and bay windows shall be supported by wood brackets, or tapered or square posts. Figure 6-31 - Craftsman Illustrative Photo Figure 6-32 - Bracketing of a Roof Gable Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • CRAFTSMAN Roof and Eaves Low pitched roof, 3:12 min - 5:12 max ratio, with gables facing primary street or side street. -ol(� Eaves Overhangs with rafter tails, exposed Eaves, and metal brackets. Dormers Proportioned and detailed as scaled down versions of the building. Balcony Wooden upper floor balconies provide usable outdoor space. Windows Vertical or square shapes. Change in Materials ■ Ground floor brick, stone, or stucco materials change to shingle or clapboard siding on upper floors. Piers Piers are a minimum of 6"x6" if wood posts. Base of the Building Footer element and ground floor all be brick, stone, stucco or shinale materials. Figure 6-33 - Craftsman Elements Diagram Illllir�..,_. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 90 ARCHITECTURAL STYLES • ART DECO Figure 6-34 - Art Deco Illustrative Photo 6.5 Art Deco Art Deco emerged in the US in the 1920s and 30s, and was the first widely popular modern style, spreading through large 6 cities and small towns alike. The style made a major impact on commercial, institutional, and large-scale residential buildings . throughout California. The Art Deco style is characterized by — — — Volumes that step back at upper floors, long pilasters that run the entire Height of the building, flat roofs, smooth lines, —' geometric shapes, and streamlined forms. Windows typically are located between the pilasters and, between floors, are 1 0 often separated by decorated transom panels. Although towers may have roofs clad in metal, the overall emphasis remains on 01 0 verticality and geometric ornamentation. Decorative features, such as infill panels, entry doors or canopies, incorporate strong geometric motifs, sometimes inspired by pre-Columbian architecture, and are often made of contrasting materials, such as metal or ceramic tile. The more exuberant versions of the style incorporate aggressive geometries of chevrons or ziggurats in Fagade design, while a more streamlined version, sometimes referred to as Arte Moderne, utilizes more sedate compositions with a horizontal emphasis. A. Applicability 1. This style is applicable to all mixed -use and multifamily zones. I F r - z Figure 6-35 - Art Deco Illustrative Photo 91 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES @ ART DECO B. Massing 1. Building Fagade sections shall have either dominant vertical decorative or functional elements such as grouping of windows, piers or decorative band or horizontal decorative or functional elements, but not both within the section of the Fagade. 2.Where tower elements are utilized, they shall rise above the roof Cornice. C. Base and Ground Floor 1. Ground floor exterior walls shall be supported on a base composed of stone, cast concrete, brick, glazed terra cotta tile, stucco, or glazed ceramic tile (bathroom tile is not permitted). 2.The entire ground floor Height may be articulated as the base of the building. D. Primary Walls of Upper Floors 1. A Primary Fagade Plane shall account for 50-80 percent of the Upper Floor Fagade. For the purposes of this calculation, windows and doors, which sit within two inches from the surface of the Fagade is calculated as part of the Primary Fagade Plane. At least 10 percent of the Fagade shall sit on at least one additional Fagade Plane (a secondary plane) projected out from or recessed in from the Primary Fagade Plane by a minimum of one foot. Balcony rails may be included as part of the secondary Fagade Plane. There is no limit to the number of Fagade Planes provided that the Primary Fagade Plane occupies at least 60 percent of the total Fagade. 2.Where pilasters running the entire Height of the building are utilized, the combined surface of the outer edge of the pilasters may be included as part of the secondary Fagade Plane. 3. Fagades shall be composed of stucco, fiberboard, brick, or tile, however, included in those materials shall be both polished and matte finishes on separate elements, ensuring that each finish covers at least 15 percent of the design's total surface area. 4.Materials shall be used to create vertical or horizontal elements (but not both) through exaggerated piers or horizontal bands. 5.At least one geometric inlay using contrasting materials shall be utilized in each Fagade section. Figure 6-36 - Art Deco Illustrative Figure 6-37- Ground Floor as Base Photo Figure 6-38 - Art Deco Illustrative Photo ■ ■ ■ o Figure 6-40 - Extensions with Metal Panels Figure 6-39 - Art Deco Illustrative Photo Figure 6-41 - Undulating Parapet Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 92 DIAMOND BAR ARCHITECTURAL STYLES • ART DECO E. Roof -Wall Transitions 1. Exterior walls shall extend beyond the roof level and form a Parapet that is configured in one of three ways: a. Pilasters that continue beyond Height of interstitial walls, b. Walls that continue beyond Height of the pilasters, c. Wall and pilaster that reach to same Height. 2.Nothing in the requirement above shall preclude the use of Cornice lines, or the use of contrasting metal tile, or other inlaid materials as part of Parapet. F. Roof 1. Roofs shall be flat with the exterior walls extending beyond the roofline to form Parapet walls. G. Drainage 1. Roof drainage shall be located within walls of the building itself and therefore not visible on the Fagade except that external scuppers and downspouts may be utilized on rear Fagades. H. Door and Window Openings 1. Individual windows shall be multi -paned, with a transom window above the main window. Alternatively, Glass Block is permitted as a window type. 2. Under each window, either as a sill or spandrel shall be a decorative area of at least one -foot in Height. This can be made of a contrasting material to the Fagades primary surface, or the primary surface but installed in a contrasting pattern. 3. Windows shall have vertical dimensions that are at least 1.5 times the width. Notwithstanding the above requirement, up to three windows may be grouped together within a larger frame. 4. Windows shall not cut into the pilasters. 5. Door and window openings on the Upper Floors of Primary Frontages shall conttiue a minimum of 25 percent of the Fagade. 6. Windows on upper floors shall appear to be "punched" by recessing them from the surface by a minimum of two inches. Where windows are arranged in groups of two or three, the entire group shall be recessed from the outer surface. I. Attached Elements 1. For the ground floor of mixed -use buildings, a projecting canopy constructed of metal, fiberglass and/or glass of at least three feet in depth shall be provided over retail storefronts. 2.Awnings, canopies, and upper floor balconies or bay windows are subject to Encroachment requirements. See DBCC Section 22.16.090(3) and Section 3.8 of this document. 3. Projecting balconies must project at least three feet beyond the primary Building Face. 4.Balcony railings shall be constructed of metal, and must include a geometric pattern, covering no less than 50 percent of the total railing area. These could include geometric shapes, chevrons, zigzags or repeating linear elements. 11. � 1� E4 Figure 6-42 - Stepped -Back Volumes ARCHITECTURAL STYLES • ART DECO Roofs Roofs shall be flat with the exterior walls extending beyond the roof line to form Parapet walls. 00 ❑❑❑ I [-]E:]F--] HI Windows Under each window, either as a sill or spandrel shall be a decorative area r of at least one -foot in �� L Height. E—] F1 F-1 FIFI L FIF-1 L Windows ❑ ❑❑ r Individual windows shall be L multi -paned, with a transom ❑ ❑❑ r window above the main L window. r F-1 F-1 L Walls Materials shall be used to give vertical or horizontal emphasis (but not both) through exaggerated piers or horizontal bands. Base The entire ground floor Height may be articulated as the base of the building. Figure 6-44 - Art Deco Elements Diagram (Ground Floor Commercial) Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 94 DIAMOND BAR ARCHITECTURAL STYLES • ART DECO Roofs Roofs shall be flat with the exterior walls extending beyond the roof line to form Parapet walls. Under each window, either as a sill or spandrel shall be a decorative area of at least one -foot in Height. Windows Individual windows shall be multi -paned, with a transom window above the main window. Walls Materials shall be used to give vertical or horizontal emphasis (but not both) through exaggerated piers or horizontal bands. Base The entire ground floor Height may be articulated as the base of the building. Figure 6-45 - Art Deco Elements Diagram (Ground Floor Residential) 95 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 96 ARCHITECTURAL STYLES • CALIFORNIA CONTEMPORARY Figure 6-46 - California Contemporary Illustrative Photo 6.6 California Contemporary The California Contemporary style refers to the streamlined Modernism that flourished in the middle of the last century in Southern California and throughout the country. Influenced by the climate and products of industrial design, the style featured flat roofs, asymmetrical and streamlined building composition, repetitive building elements articulated as abstract planes or forms, and expanses of glass that allow integration between interior and exterior spaces. The use of industrial materials such as glass, concrete and fiberglass in combination with natural materials is common. Given its abstract nature, the California Contemporary style relies heavily on the use of a "parti" or a set of major decisions about the overall organization of the building mass as a formative element. The process for buildings in this style shall begin with the parti, which shall include the following specific formal elements: an asymmetric composition with a horizontal emphasis balanced with vertical feature(s); a subdivision of the overall building form into discrete and distinguishable masses; the articulation of the exterior surface into planes with a visible Layering of elements, and expanses of glass. Unique Facade features may be highlighted with a bright or contrasting color. Despite its use of an abstract vocabulary, buildings shall be articulated with a human scale. A base and middle shall be established; a cap or attic Story may be clearly articulated or implied through modest upper level adjustments such as a taller Parapet. Figure 6-47 - California Contemporary Illustrative Photo 97 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development ARCHITECTURAL STYLES • CALIFORNIA CONTEMPORARY A. Applicability 1. This style is only applicable to mixed -use zones only. B. Massing Buildings of this style shall be composed to create depth within the Fagade itself referred to as "Layered Massing". a. Layered Volumes: Buildings must include a minimum of two Volumes with differing Heights , materials, colors and/or widths. These Volumes may abut one another or appear to be "Layered" with one appearing to overlap the other in whole or in part. There is no maximum number of Volumes. b. Bay System Alignment: These Volumes or Layers shall align with a regular bay system, which may be structural or non-structural. c. Layered Projection: Each Volume or Layer shall project or recess a minimum of four inches from the adjacent plane. Maximum depth of these Projections or recessions is not regulated. d.Overlapping Masses: There are two methods for combining Volumes and Layers: • Volumes must be physically adjacent to other Volumes along the Fagade. • Alternatively, Layers must physically overlap adjacent Volumes or other Layers. e. Material Coordination: Materials and their color and application shall follow the bay divisions. Each bay shall use consistent material placement, finishes, or patterns to visually reinforce the bay system. f. Prohibited Conditions: Fagade Compositions with non -repetitive Layering, random massing, or components that do not meet the above Projection, overlap, or bay alignment requirements are not permitted. g.The quantity of Volumes or Layers is unregulated. C. Base and Ground Floor 1. A base is not required for this style. Figure 6-48 - Example of a Base Articulated as Glass Panels Figure 6-49 - Example of California Contemporary Townhouse ICJ Figure 6-50 - California Figure 6-51 - Different Materials Contemporary Illustrative Photo Identify Different Fagade Planes Figure 6-52 - Roof Articulated with Projected Metal Overhang Serving as a Cornice Figure 6-53 - California Contemporary Illustrative Photo Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 98 ARCHITECTURAL STYLES • CALIFORNIA CONTEMPORARY D. Primary Walls of Upper Floors 1. A Primary Fagade Plane shall account for 40-70 percent of the Upper Floor Fagade. For the purposes of this calculation, windows and doors, which sit within two inches from the surface of the Fagade are calculated as part of the Primary Fagade Plane. At least 30 percent of the Fagade shall sit on at least one additional Fagade Plane (a secondary plane) projected out from or recessed in from the Primary Fagade Plane by a minimum of two feet. Balcony rails may be included as part of the secondary Fagade Plane. There is no limit to the number of Fagade Planes provided that the Primary Fagade Plane occupies at least 40 percent of the total Fagade. 2.Fagade Planes are expressed as expanses of wood, cementitious, or metal siding, plaster or stucco, metal panels, or cast concrete. These various materials may be used in conjunction with one another, for example to identify different Fagade Planes. 3. For buildings or portions of buildings which are four or more Stories in Height, it is necessary to provide articulation for the top Story of the building. This may be accomplished by a color change, material change, the extension of a Primary Fagade Plane from behind a secondary plane, and/or a Cornice/ Belt Course at the bottom of the uppermost Story. Other techniques may be approved by the Director on an individual basis. E. Roof -Wall Transitions 1. The building cap is where the side of the building meets the top. It shall incorporate the roof Parapet or roofline. 2.Parapet of flat -roofed Volumes may be articulated as an extension of the wall below or as a distinct railing. r n- c H. Door and Window Openings 1. Primary doorways shall be located asymmetrically from the center of the building. 2.Windows and Doors on flat surfaces shall be recessed at least two inches to create a shadow line or have a projecting surround or a projecting rain screen assembly of at least four inches beyond the window to create a shadow. The exception to this is where Glass Block is used as a window type. As such cases, the Glass Block may be flushed with the surrounding exterior surface. 3. Door and window openings on the Upper Floors of Primary Frontages shall constitute a minimum of 33 percent of the Fagade. I. Attached Elements A minimum of 10 percent of all windows and doors facing a Primary Fagade shall have horizontally oriented, metal sun shades supported by metal brackets extending at least 18 inches from the outer face of the window or door. This requirement is waived where the windows are recessed at least four inches from the outer wall (or rain screen). Attached Balconies may substitute for the attached sun shades. 2.Awnings, canopies, and upper floor balconies or bay windows are subject to Encroachment requirements. See DBCC Section 22.16.090(3) and Section 3.8 of this document. 3. Projecting balconies shall project at least three feet beyond the primary Building Face. 4.Balcony railings shall be constructed of perforated metal or laminated glass. If the ground floor of mixed -use buildings is projecting forward from the floors above, a projecting canopy of at least three feet in depth shall be provided over retail storefronts. Projecting canopies are not required, where the ground floor is recessed from the floors above. ARCHITECTURAL STYLES • CALIFORNIA CONTEMPORARY Roof Wall Connections Building caps shall facilitate roof forms that are integral to the building's design on all sides of the structure. 117 no io IHEE: -om(� Attached Elements Awnings, canopies, anc upper floor balconies or bay windows are subject to Encroachmc requirements. Windows Windows and Doors on flat surfaces must be recessed at least two inches to create a shad line or have a projectim surround or a projectirn rain screen assembly of at least four inches beyond the window to create a shadow. Walls Fagade Planes are expressed as expanses of wood, cementitious, metal siding, plaster or stucco, metal panels, of cast concrete. Base Shall be articulated as distinct from Upper Floors, for commercial uses. Figure 6-55 - California Contemporary Elements Diagram (Ground Floor Commercial) Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 100 ARCHITECTURAL STYLES • CALIFORNIA CONTEMPORARY Roof Wall Connections Building caps shall facilitate roof forms that are integral to the building's design on all sides of the structure. Attached Elements Awnings, canopies, anc upper floor balconies or bay windows are subject to Encroachmc requirements. Windows Windows and Doors on flat surfaces must be recessed at least two inches to create a shad line or have a projectim surround or a projectirn rain screen assembly of at least four inches beyond the window to create a shadow. Walls Fagade Planes are expressed as expanses of wood, cementitious, metal siding, plaster or stucco, metal panels, of cast concrete. Figure 6-56 - California Contemporary Elements Diagram (Ground Floor Residential) 101 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development Page Left Intentionally Blank Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 102 GLOSSARY OF TF r-%Aqs Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development GLOSSARY OF TERMS GLOSSARY OF TERMS This chapter provides definitions of terms and phrases used in this Objective Design Standards that are technical or that may not reflect common usage, and is intended to supplement the Development Code Definitions found in Chapter 22.80 of the Diamond Bar City Code (Development Code). If a definition in this section conflicts with a definition found in the Development Code, these definitions shall control for the purposes of new developments. If a word or phrase used in this Objective Design Standards is not defined in this section, or in the Development Code, the Director shall make a determination, giving deference to common usage and the context in which the term or phrase is used. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 104 GLOSSARY OF TERMS A Access Point A point of entry on a Block Front providing access to parking or service facility areas. Apparent Building A portion of a building designed to appear as distinct from the rest of the building, and with its own entrance. Architectural Features Building elements that are not strictly integral to the building's massing, Fenestration or Frontage condition, but are added to serve a decorative or functional purpose. They include elevator overruns, stair towers, Shade Structures like pergolas or awnings, Cornices, cupolas, projecting friezes or grills, photovoltaic panels, attached sculpture or other artwork, clock towers, turrets and the like. Occupiable spaces other than elevator overruns, stair towers or mechanical equipment spaces are not considered Architectural Features. Architectural Style The characteristic form and detail of buildings from a particular historical period or school of architecture. Belt Course A horizontal band or row of masonry, tile, or other decorative material, including paint set into or attached to a wall, and forming part of an exterior architectural composition. Set in line with window sills it helps to make the horizontal line of the sills visually more prominent. Set between the floors of a house, it helps to make the separate floors distinguishable from the exterior of the building. Block Block Front The plane of the edge of each side of a Block or section of a Block facing a public or private right-of- way or Public Space. Block Length The length of a parcel or series of parcels measuring from the edge of one public right-of-way to another or from the edge of one public right-of-way to the opposite end of the parcel should it adjoin a private parcel edge. Build -to Line A line, parallel to the property line, that must be occupied by a specified percentage of the building Fagade. The Build -to Line is measured as a distance from the property line. For example, a five-foot Build - to Line would be located five feet from the property line within the parcel. Building Face The exterior wall of a building. Building Frontage See DBCC Section 22.80.020. Building Type A structure category defined by its massing, entry location, disposition on the lot, and configuration, including Frontage and Height. It is occasionally defined by its function as well. There are eleven Building Types permitted: Townhouse, Flex/Loft, Small Multi -Family, Six/Eight Packs, Walk -Up, Carriage House, Courtyard, Small Mixed -Use, Urban Block, Wrap Building and Mixed -Use Big Box. C Clear Sight Triangle An area bounded by streets on all sides used An area near the exit of a driveway or parking to regulate the land uses, Heights, and design structure that must remain free of visual requirements in the Objective Design Standards. obstructions —such as walls, landscaping, or signage— to ensure that drivers can clearly see approaching / pedestrians and vehicles before entering a public walkway or street. 105 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development GLOSSARY OF TERMS Common Open Space Outdoor open spaces that are shared and accessible only to building residents and their visitors which may include courtyards, gardens, play areas, outdoor dining areas, recreational amenities, and rooftop open spaces. Conceptual Examples depict one possible design that would substantially conform to the Standards, but are not determinative. Connection A space that links one physical space to another. It may be traversable by pedestrian, bicycle or automobile traffic. Cornice Any horizontal molded decorative Projection that crowns a building, i.e. at the meeting of the roof and wall. A Projecting Cornice on a building may have the function of diverting rainwater free of its walls, but it purpose is primarily decorative. Courtyard Building A Building Type defined in Section 3.10. E Decorative Detail An intricate design or embellishment that enhances the aesthetic appeal of a structure. Decorative Details can encompass ornamentation, moldings, and patterns that enrich the style of a building. Density See DBCC Section 22.80.020 Development Code Title 22 of the Diamond Bar City Code (DBCC), the municipal code of the City of Diamond Bar, California Dooryard Dooryard fronts are located in front Setbacks and provide small landscaped and paved yards at building entrances. They are often enclosed by low walls, fences, or hedges. Driveway A paved vehicular access way that provides a direct Connection between a public or private street and on - site parking areas, garages, or carports. A Driveway shall be located on private property and shall not be used for parking unless otherwise specified. Driveways may be shared by multiple units or buildings where permitted. E Eave The edge of the roof which overhangs the face of a wall and, normally projects beyond the building. The Eave forms an overhang to divert water clear of the walls and, in some cases, provides shade. Encroachment Any structural element (including Architectural Features) that extends from the Building Face into the public right-of-way or Setback. Permitted Encroachments are provided in Section 3.8. F Fagade A Building Face that is along a Frontage. Fagade Composition The expression of a Fagade through a variety of techniques such as patterns, fenestration, materials, texture, or finishes. Fagade Composition is used to create the architectural character and design theme of a building. Fagade Plane Any stretch of a building Fagade existing along the same axis line, regardless of pattern differentiation or change in rhythm. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 106 GLOSSARY OF TERMS Fagade String A series of Townhouses or Flex/Loft units attached together in a single building. Fagade Width The horizontal distance along a street or public way of a single building Fagade. Faux Stone Appearance A simulated stone veneer that appears artificial either because of visible seams in the veneer panels, uniformity in shape, size, and coloration, repetitive patterns, and/or a uniform edge. Fenestration The arrangement and design of windows and other openings on a building's Fagade. Flex/Loft Building A Building Type defined in Section 2.5. Floor Area Ratio (FAR) See DBCC Section 22.80.020. For projects subject to these Objective Design Standards, the following shall be excluded from the total Floor Area: • Garages: provided they are screened by habitable space of at least 20-feet in depth along all Public or Private Streets; • Loading areas, and Trash enclosures; • Elevator shafts, except that one floor shall be included as part of the floor area; and • Transformer enclosures. Footcandle A footcandle is a unit of measurement for illumination, or how much light falls on a surface. One footcandle equals one lumen per square foot. In other words: • 1 footcandle = 1 lumen / 1 square foot It measures the intensity of light hitting a surface, not the light emitted by a source (that's measured in lumens). • Example: If a lamp provides 100 lumens of light evenly distributed over an area of 100 square feet, the illumination on that surface is one footcandle. Footprint Footprint or building Footprint provides the outline of a building drawn along the exterior walls, with a description of the exact size, shape, and location of its foundation. Forecourt A Frontage Type as defined in Section 4.8. Frontage See Building Frontage, DBCC Section 22.80.020. Frontage Occupancy The minimum percentage of the Block Front that must contain a building. Frontage Occupancy requirements shall apply to the first three floors of a building. Frontage Type As defined in Chapter 4. Front Yard See DBCC Section 22.80.020. Furnishing Zone A multi -purpose area that serves as a buffer between the pedestrian travel way and the vehicular travel way and parking on the street. It provides space for sidewalk appurtenances such as street trees, planting strips, street furniture, public art, sidewalk cafe seating, sign poles, temporary signage, signal and electrical cabinets, fire hydrants, bicycle racks and bus shelters. 107 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development GLOSSARY OF TERMS G Glass Block A hollow translucent Block usually with ribbed exterior made by fusing two sections of clear pressed glass at high temperature and used as a building material chiefly for wall panels. Gross Lot Area See Lot Area, DBCC Section 22.80.020. Ground Plane A horizontal plane of reference from which vertical measurements can be taken. Unless otherwise specified, the ground plan refers to the adjacent grade at the sidewalk. I Habitable Encroaching Space The portion of the building enclosed by walls and a roof that projects beyond the Building Face along the ground floor. Habitable Projecting Space The portion of the building enclosed by walls and a roof that projects beyond the Building Face and is raised a minimum of nine feet from the sidewalk, such as bay windows. Habitable Space Space in a structure that is occupiable and is used primarily for living, sleeping, eating, selling of goods, or cooking. Bathrooms, closets, halls, storage areas and utility spaces are not considered habitable spaces. Hardscape Non -living elements of landscaping that primarily consist of paving materials such as brick, stone, wood, and concrete. Height See DBCC Section 22.16.060 (Height measurement and Height limit exceptions). Horizontal Plane Break See Figure 2-1. Illustrative Examples that illustrate one possible design that would substantially conform to the Standards but are not determinative. L Landscaped Area See DBCC Section 22.80.020. Layer As part of a Fagade Composition, a Layer is a Volume that appears to overlap a recessed portion of the Fagade. Layered Massing See Section 6.6.B. Layered Volumes Where multiple Volumes appear to abut or overlap one another. Living Areas Rooms designated as living room, family room, den, study, library and/or kitchen, rather than sleeping and service rooms. Lot Area, Gross See Lot Area, DBCC Section 22.80.020 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 108 GLOSSARY OF TERMS M Minimum Frontage Occupancy (Also, Minimum Building Frontage Occupancy) is the minimum percentage of a Block Front at which a Building Frontage is set either at or within twelve inches of the Build -to Line or within the minimum and maximum Setback lines, as required by the Block development standards. Mixed -Use Big Box A higher Density Building Type defined in Section 2.13. 2 Non -Habitable Encroaching Space The portion of the building that extends beyond the Building Face along the ground floor, which is not enclosed by walls and a roof, such as a Stoop. Non -Habitable Projecting Space The portion of the building that extends beyond the Building Face, which is not enclosed by walls and a roof and raised a minimum of nine feet from the ground floor, such as a balcony. Non -Habitable Space Parapet A barrier that is an upward extension of a wall at the edge of a roof, Terrace, balcony or walkway. Where extending above a roof, a Parapet may simply be the portion of an exterior wall that continues above the edge line of the roof surface, or may be a continuation of a vertical feature beneath the roof. They are primarily used as guard rails or to conceal rooftop equipment. Paseo A public place or path designed for walking; promenade that connects into or through a development. Plane Break The area of the building where the plane of the Fagade varies in depth. Plane Breaks can be horizontal or vertical. Planter An above grade container for planting. Plaza A type of Public Space that is enclosed by Building Frontages on all sides, and will reclaim Public Space for pedestrian use from otherwise predominantly vehicular intersections. The portion of a building which is not enclosed by walls and a roof, such as a Stoop, balcony, or roof deck. Podium n Objective Design Standards Objective Design Standards are defined in California Government Code sections 65913.4 and 66300(a)(7) as standards that involve no personal or subjective judgment by a public official and are uniformly verifiable by reference to an external and uniform benchmark or criterion available and knowable by both the development applicant or proponent and the public official before submittal. The lower floors of a building that form the "base" of a building typically including a courtyard level above. Podiums typically include structured parking, a courtyard level above, a different and larger floorplate than floors above, and may be a different construction type than the rest of the building. uw ui>) 0t LEI Im om on mo m [0 ��'�ID ]10 Im am am mum Uu� ED m�11 m m (Do m�Q� mom L7 g-1�,;��p Figure 7-1 - Isometric View of a Podium 109 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development GLOSSARY OF TERMS Podium Level The level directly above the Podium. The Podium Level typically includes a courtyard, a smaller building area than the levels below, and a change in construction type. Predominant Building Height The Height at which at least 50% of a building is measured. Primary Entrance The main point of access for pedestrians into a building. Primary Fagade Plane Majority area of the Fagade that is in the same plane. Principal Frontage The Frontage designated to bear the addresses of and Primary Entrances to the individual units of a Townhouse or Flex/Loft Building, or other building. Private Open Space Outdoor open space areas that are intended for private use for each dwelling unit and may include balconies (covered or uncovered), private gardens, private yards, Terraces, decks and porches, etc. Projecting Cornice A horizontal decorative molding that crowns a building, and extends beyond the Building Face Projection An architectural element or portion of the building that extends beyond the Building Face into the public right-of-way or Setback that is raised a minimum of nine feet from the sidewalk or open space. Public Realm Composed of public rights of way and private Front Public Space Public outdoor space reserved for active and passive recreation. 0 Roadway The area in the right-of-way as measured from curbface to curbface intended for vehicular travel, as well as bicycle travel, in designated areas. Setback See DBCC Section 22.80.020 Shade Structure A roofed or partially roofed structure that provides shade. It can be freestanding or fixed to a building. The roof material may be composed of fabric and be removable, or temporary and made of plants or vines. Alternatively, the roof may be fixed or permanent. Sidewalk Grade A level plane along the top of the sidewalk pavement. Sign See DBCC Section 22.80.020. Six/Eight Pack A Building Type defined in Section 2.6. Special Paving Includes any hard surface flooring material except non -tinted poured -in -place concrete and asphalt that can be used in outdoor flooring applications, Special Paving can include, saw -cut concrete, concrete pavers, tinted and/or stamped concrete, brick, stone, porcelain and/or ceramic, provided such materials are approved by the Diamond Bar Public Works Department. Yards, the Public Realm is the communal social setting of urban life. The term Public Realm is not intended to provide general public with any legal access rights to private property. Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development 110 GLOSSARY OF TERMS Specialty Window Any window that comes in a non-traditional shape or configuration, such as a circle, oval, arch, or triangle, i.e., not typically found in standard rectangular windows. Specialty Windows can be fixed or operable. Stoop A Frontage Type as defined in Section 4.5. Shopfront A Frontage Type as defined in Section 4.3. Urban Block A medium Density Building Type defined in Section 2.12. Urban Frontage A Frontage Type as defined in Section 4.10. V Vertical Plane Break See Figure 2-1. Story Any level part of a building with a floor that could be Volume used by people (for living, work, storage, recreation, etc.), excluding levels of the building that are not As part of a Fagade Composition, a Volume is a covered by a roof such as the Terrace on the rooftops Projection or recession of building mass, as part of Layered Massing technique. of many buildings. Street, Public or Private See Street, DBCC Section 22.80.020. Subdivision See DBCC Section 22.80.020. Swale A low or slightly depressed natural area for drainage. 11 Terrace, Commercial and Residential A Frontage Type as defined in Sections 4.4 and 4.9. Thin Veneer A lightweight Layer of stone or brick veneer that appears to be less than 1.5 inches thick. Townhouse A Building Type defined in Section 2.3 V W Walk -Up Building A Building Type defined in Section 2.7. Water Feature A design element where open water performs an aesthetic or recreational function such as a fountain. Water Table A projecting course or molding on the lower exterior wall of a building designed to deflect rainwater away from the foundation. Wrap Building A medium Density Building Type defined in Section 2.11. Z Zoning District See DBCC Section 22.80.020. Zoning Ordinance See DBCC. 111 Diamond Bar Objective Design Standards for Multifamily & Mixed -Use Development m OF TE I F .Y 10 mot '-A 'k, 01U Addendum No. 2 to the Diamond Bar Comprehensive General Plan Update and Climate Action Plan Environmental Impact Report State Clearinghouse No. 2018051066 Prepared for: City of Diamond Bar 21810 Copley Drive Diamond Bar, CA 91765 Prepared by: Sapphos Environmental, Inc. 430 North Halstead Street Pasadena, California 91107 February 2026 Page 202 of 328 SECTION TABLE OF CONTENTS PAGE 1.0. INTRODUCTION AND OVERVIEW............................................................................... 1 1.1 PURPOSE...........................................................................................................1 1.2 ADDENDUM ORGANIZATION............................................................................3 1.3 ADDENDUM SCOPE OF ENVIRONMENTAL REVIEW.......................................4 1.4 ADOPTION AND AVAILABILITY OF ADDENDUM..............................................5 2.0. PROJECT DESCRIPTION............................................................................................. 6 2.1 BACKGROUND...................................................................................................6 2.2 PROJECT LOCATION.........................................................................................6 2.4 PROPOSED PROJECT.....................................................................................12 2.5 APPLICABILITY OF ODS..................................................................................13 2.6 GOALS AND OBJECTIVES...............................................................................13 2.7 DISCRETIONARY APPROVALS.......................................................................15 2.8 CONSTRUCTION..............................................................................................15 3.0. ENVIRONMENTAL ANALYSIS.....................................................................................16 3.1 AESTHETICS....................................................................................................17 3.2 AIR QUALITY....................................................................................................20 3.3 BIOLOGICAL RESOURCES..............................................................................25 3.4 CULTURAL RESOURCES................................................................................30 3.5 ENERGY...........................................................................................................33 3.6 GEOLOGY, SOILS, AND SEISMICITY..............................................................36 3.7 GREENHOUSE GAS EMISSIONS....................................................................41 3.8 HAZARDS AND HAZARDOUS MATERIALS.....................................................44 3.9 HYDROLOGY AND WATER QUALITY..............................................................50 3.10 LAND USE AND HOUSING...............................................................................56 3.11 NOISE...............................................................................................................60 3.12 PUBLIC FACILITIES AND RECREATION.........................................................63 3.13 TRANSPORTATION..........................................................................................68 3.14 TRIBAL CULTURAL RESOURCES...................................................................72 3.15 UTILITIES AND SERVICE SYSTEMS...............................................................74 3.16 WILDFIRE..........................................................................................................77 4.0. LIST OF PREPARERS..................................................................................................81 4.1 LEAD AGENCY.................................................................................................81 4.2 CONSULTANT..................................................................................................81 5.0. REFERENCES..............................................................................................................82 TABLE PAGE 1 Step -by -Step Application of ODS...................................................................................14 2 2021-2029 Regional Housing Needs Assessment.........................................................56 Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page i Page 203 of 328 FIGURE PAGE 1 Project Location...............................................................................................................8 2 Regional Vicinity..............................................................................................................9 3 Topographic Quadrangle...............................................................................................10 4 City Land Use Distribution.............................................................................................11 APPENDICES A Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development B Mitigation Monitoring and Reporting Program Diamond Bar Objective Design Standards February 2026 Sapphos Environmental, Inc. Page ii Addendum No. 2 to the EIR Page 204 of 328 1.0. INTRODUCTION AND OVERVIEW This Addendum No. 2 to the Diamond Bar General Plan 2040 and Climate Action Plan Environmental Impact Report (State Clearinghouse No. 2018051066) (hereafter, Certified EIR)' is prepared pursuant to and in compliance with Section 15164 of the California Environmental Quality Act (CEQA) Guidelines for minor refinements to the Diamond Bar General Plan 2040 (General Plan 2040)2 being undertaken by the City of Diamond Bar (City). The City adopted the General Plan Update and Climate Action Plan in 2019. The potential environmental impacts of the General Plan 2040 and Climate Action Plan were analyzed in the Certified EIR. In 2022, the City adopted the 2021-2029 Housing Element Update.3 The City concurrently amended the General Plan 2040 Land Use and Economic Development Element. The potential impacts of the 2021-2029 Housing Element Update and concurrent Land Use and Economic Development Element amendment were determined to be within the scope of the Certified EIR. The City concluded that neither a subsequent nor a supplemental EIR was required. Accordingly, the City adopted Addendum No. 1 to the Certified EIR on August 11, 2022. Addendum No. 2 describes the proposed Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development (hereafter, proposed project). The proposed project sets minimum design standards for multifamily and mixed -use development throughout the City to be used during the development review process, with the intent that all new multifamily and mixed - use developments be required to adhere to the proposed project (Appendix A, Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development). The General Plan 2040 established standards related to development density for all land uses with the City, including multifamily residential and mixed -use development. As described in the Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development, the proposed project would further establish objective design standards that would dictate the bulk, mass, and design of multifamily residential and mixed -use development, further refining the General Plan 2040 standards. The Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development have been developed consistent with the General Plan 2040 and 2021-2029 Housing Element Update, and, as such, remains within the scope of the Certified EIR. 1.1 PURPOSE The purpose of Addendum No. 2 to the Certified EIR is to document technical changes and additions to the project description. The analysis evaluates whether in-depth, further environmental review is required such as a subsequent or supplemental EIR (Public Resources Code § 21166; CEQA Guidelines § 15162). The State CEQA Guidelines Appendix G checklist for Initial Study was modified for use in the addendum analysis. Instead of asking whether the project would have "potentially significant" impacts, the checklist questions were modified consistent with the State CEQA Guidelines on subsequent environmental review to ask whether the proposed project would result in a substantial change in the project requiring major revisions to the prior EIR, or a substantial change in circumstances requiring major revisions to the EIR, or new City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft Environmental Impact Report. https://ceqanet.opr.ca.gov/2018051066/2 2 City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan- 2040 3 City of Diamond Bar. 2022. Diamond Bar General Plan 2040 Housing Element Update 2021-2029. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 1 Page 205 of 328 information showing new significant impacts or a substantial increase in the severity of previously identified significant impacts (Public Resources Code § 21166; CEQA Guidelines § 15162). An addendum to the EIR is appropriate when changes to a project would require minor modifications to the previous EIR and would not entail new significant environmental effects or a substantial increase in the severity of previously identified significant effects. In accordance with State CEQA Guidelines Section 15164, this addendum to the Certified EIR incorporates, by reference, the analysis contained Certified EIR and addresses only the new issues specific to the proposed project as described in this document. Section 15164 of the State CEQA Guidelines provides the following guidance regarding the preparation of an addendum to an EIR: (a) The lead agency or responsible agency shall prepare an addendum to a previously certified EIR if some changes or additions are necessary but none of the conditions described in Section 15162 calling for preparation of a subsequent EIR have occurred. (b) An addendum to an adopted negative declaration may be prepared if only minor technical changes or additions are necessary or none of the conditions described in Section 15162 calling for the preparation of a subsequent EIR or negative declaration have occurred. (c) An addendum need not be circulated for public review but can be included in or attached to the final EIR or adopted negative declaration. (d) The decision making body shall consider the addendum with the final EIR or adopted negative declaration prior to making a decision on the project. (e) A brief explanation of the decision not to prepare a subsequent EIR pursuant to Section 15162 should be included in an addendum to an EIR, the lead agency's findings on the project, or elsewhere in the record. The explanation must be supported by substantial evidence. Regarding Section 15164(e) of the State CEQA Guidelines, a subsequent EIR is not required pursuant to Section 15162 of the State CEQA Guidelines because none of the following circumstances have occurred with respect to the proposed project: (1) Substantial changes are proposed in the project which will require major revisions of the previous EIR or negative declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; (2) Substantial changes occur with respect to the circumstances under which the project is undertaken which will require major revisions of the previous EIR or Negative Declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or (3) New information of substantial importance, which was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified as complete or the Negative Declaration was adopted, shows any of the following: Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 2 Page 206 of 328 (A) The project will have one or more significant effects not discussed in the previous EIR or negative declaration; (B) Significant effects previously examined will be substantially more severe than shown in the previous EIR; (C) Mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, but the project proponents decline to adopt the mitigation measure or alternative; or (D) Mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponents decline to adopt the mitigation measure or alternative. 1.1.1 Summary of Findings As demonstrated in the initial study below, implementation of the proposed project would not require major revisions to the Certified EIR because the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts analyzed in the Certified EIR. In addition, the information throughout this addendum affirms that there is no new information of substantial importance that was previously unknown and is now available. Therefore, a subsequent EIR would not be required pursuant to Section 15162 of the State CEQA Guidelines. The City has thus determined an addendum to the previously Certified EIR to be the appropriate environmental compliance document for the proposed project. Addendum No. 2 to the Certified EIR has been prepared for the Lead Agency as defined in Section 15367 of the CEQA Guidelines. Lead Agency Contact Information City of Diamond Bar Greg Gubman Planning Division 21810 Copley Drive Diamond Bar, CA 91765 1.2 ADDENDUM ORGANIZATION This document is organized as follows pursuant to the requirements of the State CEQA Guidelines: • Section 1.0, Introduction, describes the background of the proposed project; explains the rationale for preparing an addendum to the EIR as the appropriate form of environmental review pursuant to CEQA; and explains the purpose, scope, and content of the addendum to the EIR. Section 2.0, Project Description, describes the location, details, and objectives of the proposed project. Section 3.0, Environmental Analysis, evaluates whether the proposed refinements to the proposed project would result in new or substantially more adverse significant environmental impacts than those disclosed in the Certified EIR. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 3 Page 207 of 328 Section 4.0, List of Preparers, lists the individuals involved in preparing the document. Section 5.0, References, lists the documents and individuals consulted during preparation of this document. 1.3 ADDENDUM SCOPE OF ENVIRONMENTAL REVIEW This document incorporates the Certified EIR by reference and evaluates whether the proposed project would result in a new significant impact or a substantial increase in the severity of previously identified significant impacts. The Certified EIR analyzed the following environmental issue areas based on the City's initial analysis of environmental setting and baseline conditions and comments received during the Certified EIR Scoping Period: 1. Aesthetics 2. Air Quality 3. Biological Resources 4. Cultural, Historic, and Tribal Cultural Resources 5. Energy, Climate Change, and Greenhouse Gases 6. Geology, Soils, Seismicity, and Paleontology 7. Hazards, Hazardous Materials, and Wildfire 8. Hydrology and Water Quality 9. Land Use, Population, and Housing 10. Noise 11. Public Facilities and Recreation 12. Utilities and Service Systems 13. Transportation The Notice of Preparation (NOP) for the Certified EIR was published on May 31, 2018. In 2018, Appendix G of the State CEQA Guidelines was updated to establish the issue area of Tribal Cultural Resources. In 2019, Appendix G of the State CEQA Guidelines was updated to establish the issue areas of Energy and Wildfire. This document addresses each of the environmental resource areas previously analyzed in the Certified EIR, with updates that better reflect the changes to the State CEQA Guidelines that occurred in 2018 and 2019. Specifically, the Cultural Resources, Tribal Cultural Resources, Energy, Greenhouse Gas Emissions, Hazards and Hazardous Materials, and Wildfire sections are evaluated as separate environmental topics in Section 3.0, Environmental Analysis, of this addendum. This document analyzes the following environmental issue areas using the questions established in Appendix G of the 2025 State CEQA Guidelines. 1. Aesthetics 2. Air Quality 3. Biological Resources 4. Cultural Resources 5. Energy 6. Geology, Soils, and Seismicity 7. Greenhouse Gas Emissions 8. Hazards and Hazardous Materials 9. Hydrology and Water Quality 10. Land Use and Housing 11. Noise 12. Public Facilities and Recreation 13. Transportation Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 4 Page 208 of 328 14. Tribal Cultural Resources 15. Utilities and Service Systems 16. Wildfire 1.4 ADOPTION AND AVAILABILITY OF ADDENDUM In accordance with State CEQA Guidelines Section 15164(c), an addendum to the EIR does not need to be circulated for public review but can be included in or attached to the Certified EIR. This addendum is publicly available as part of the Certified EIR at the City of Diamond Bar Planning Division, 21810 Copley Drive, Diamond Bar, CA 91765. Diamond Bar Objective Design Standards February 2026 Page 5 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 209 of 328 2.0. PROJECT DESCRIPTION 2.1 BACKGROUND Under the General Plan 2040, current regulations governing development standards and guidelines by the City include the Diamond Bar City Code and Citywide Design Guidelines. City of Diamond Bar Zoning Ordinance The Diamond Bar Zoning Ordinance is applied to regulate the type, location, density, and scale of residential development through Title 22 (Development Code) and the Zoning Map citywide. The Development Code aims to preserve the character and integrity of existing neighborhoods. The Development Code and Zoning Map set forth residential development standards for each zoning district. City of Diamond Bar Citywide Design Guidelines The Citywide Design Guidelines was created following adoption of the 1995 General Plan and was adopted in 1998. The Design Guidelines were intended to provide design professionals, property owners, residents, staff, and decision makers with a clear and common understanding of the City's expectations for the planning, design, and review of development proposals. The guidelines contain provisions that address citywide elements, including building siting, building design, bulk and massing, and design guidelines that provide detailed design information of, among other things, the circulation system of new developments, including parking facilities, driveways, sidewalks, and pedestrian facilities. 2.2 PROJECT LOCATION The proposed project would apply to all new multifamily development and some new mixed -use development throughout the City, as well as to some existing multifamily and mixed -use development undergoing substantial improvements. The following General Plan 2040 land use designations allow for multifamily residential and mixed -use development: Medium Density Residential, Medium High Residential, High Density Residential, High Density Residential-30, Town Center Mixed Use, Neighborhood Mixed Use, and Transit -Oriented Mixed Use. Both existing and future development on parcels with these land use designations have the potential to be subject to the proposed project. As such, the study area for the proposed project is established as areas where the General Plan 2040 land use designations allow for multifamily residential and mixed -use development (Figure 1, Project Location). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 6 Page 210 of 328 The City is an approximately 9,526-acre incorporated area located on the eastern edge of Los Angeles County, California, at the far eastern edge of the San Gabriel Valley, within 30 miles of the cities of Los Angeles, Riverside, and Irvine (Figure 2, Regional Vicinity). It is bound by the cities of Industry and Walnut to the north, the cities of Pomona and Chino Hills to the east, unincorporated area of Los Angeles County within Diamond Bar's Sphere of Influence and the City of Brea to the south, and unincorporated area of Los Angeles County to the west. The western edge of the City lies at the intersection of State Route 57 (SR-57) and SR-60, with SR-57 connecting the City to Interstate 10 (1-10) 1.5 miles north and SR-60 connecting to SR-71 roughly 2 miles east. The Industry Metrolink Station is located along Diamond Bar's northern border within the City of Industry, providing east -west transit connections to Los Angeles and Riverside. The City is on the U.S. Geological Survey (USGS) 7.5-minute series San Dimas, California, and Yorba Linda, California, topographic quadrangles (Figure 3, Topographic Quadrangle). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 7 Page 211 of 328 City of Diamond Bar Multifamily Residential Medium Density Residential Medium High Density Residential High Density Residential High Density Residential-30 Mixed Use Neighborhood Mixed Use Town Center Mixed Use Transit Oriented Mixed Use Rd e JQ Q �a �a v '1 Jao 60 Diamond Bar Los Angeles ' Royal Vista Golf Course 57i ��d y� o� ly i Lanterman Development Center (Former Country rossinp Park z: r 60 �0 Di and Bar r If Course Q O S ,1 Diamo High Pue rhn 0 <J Dorada 0 V;Sca Ftd Lxc� �t c c i � I Tonner 'Cant I � I J Firestone Boy I Scout Reservation SOURCES: ESRI, Los Angeles County, City of Diamond Bar, SEL �O N 0 3,000 6,000 Ga 0 Feet 5�-------------------- 1468fi 1:60,000 V e Q- Prolecis-2-W,2_A0311 J'V _'011 I7C _A03-1 l3 f— FIGURE 1 Project Location Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 8 Page 212 of 328 tw ��-Wm r..' City of Diamond Bar �'- - _`A ab•' �V �Rj 'P�,., x 0 County Boundaries yy :-4, r ' ,. �•-il.i •r ter - _• _alt4lrl.-� f•�`LOS'°�A�i=Ne GELES .� r� .�- u Y ' BE00, RNARDINO T 1►ts6 K I� r ^ i.� i... i. . ' �l M ' r wt3► CO"✓ A ;� ,j._1G,+ ` -- . 4-.r r i .�� r !.{."7' , r% 4. < T/%ice .rr.4 � � � .�-�; • OIN ?� •�• .e : ' "RIVERSIDE lot �, wc�SAAwSr�i'wi ORANGE nNdJ►0N 50,000 NVNT rON ![ACN ' ..t fi Fowl%w1�A. w •'l, J, Feet 1:400,000 FIGURE 2 Regional Vicinity Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 9 Page 213 of 328 2.3 EXISTING CONDITIONS As discussed in the General Plan 2040, the City's overall land use pattern is characterized by large swaths of single-family residential development throughout the City along with clusters of multifamily residential and non-residential land uses. Multifamily residential development tends to be located along the major thoroughfares of Diamond Bar Boulevard, Golden Springs Drive, and Brea Canyon Road, and is often collocated with non-residential uses. Residential land makes up roughly half of all land in the city limits and is the dominant land use in the City (Figure 4, City Land Use Distribution).4 1 S % 16o/ - 50 470 4 / 1 % Commercial. Office. and Residential Mixed Use N Parks and Open Spaces 0 Public and Community Facilities ■ Vacant N Industrial Other FIGURE 4 City Land Use Distribution 4 City of Diamond Bar. 2019. Diamond Bar General Plan 2040: Chapter 2. Land Use and Economic Development. https://www.diamondbarca.gov/DocumentCenter/View/7089/2-Land-Use-Econ-Devr?bidld= (accessed September 29, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 11 Page 215 of 328 2.4 PROPOSED PROJECT The proposed project would set minimum design standards for multifamily and mixed -use development throughout the City (Appendix A) in compliance with State mandates that seek to streamline and increase housing, as well as implement Program H-8 of the City's certified 6tn Cycle (2021-2029) Housing Element. The proposed project would be used during the development review process, and all new multifamily and mixed -use developments in the City would be required to adhere to these design standards, as well as some existing multifamily and mixed -use development undergoing substantial improvements. The proposed project would ensure consistent, transparent, and measurable review of multifamily and mixed -use development projects in accordance with California law. The proposed project is intended to streamline project approvals by providing clear verifiable objective criteria for design that do not require subjective interpretation. In response to the housing crisis, legislation has been passed in the State of California to bolster the State's Housing Accountability Act, including Senate Bill (SB) 35, SB 330, SB 9, SB 6, and Assembly Bill (AB) 2011. The intent of this legislation has been to stimulate and streamline housing production housing projects that meet objective design standards (ODS). Per SB 330, SB 9, and AB 2011, an "objective design standard" means a design standard that involves no personal or subjective judgment by a public official and is uniformly verifiable by reference to an external and uniform benchmark or criterion available and knowable by both the development applicant or proponent and the public official before submittal of an application. SB 330 and SB 9 regulate a local agency's ability to establish design standards: • SB 330: This bill, the Housing Crisis Act of 2019, prohibits a county or city from enacting a development policy, standard, or condition that would have the effect of imposing or enforcing new design standards that are not objective. In essence, the State has limited a local jurisdiction's ability to apply subjective design standards, whereby the City can now only rely on the application of ODS for qualifying housing projects. SB 9: The bill authorizes a local agency to impose objective zoning standards, objective subdivision standards, and ODS, unless those standards would have the effect of physically precluding the construction of up to two units or physically precluding either of the two units from being at least 800 square feet in floor area, prohibiting the imposition of setback requirements under certain circumstances, and setting maximum setback requirements under all other circumstances. SB 35, SB 6, and AB 2011 establish opportunities to streamline housing projects; however, the streamlining can only be used if a housing project meets the criteria of meeting ODS. These streamlining opportunities cannot be used if a local agency does not have an established set of ODS. By adopting the proposed project, the City would encourage streamlined housing production through SB 35, SB 6, and AB 2011: SB 35: Under existing law, every locality has a housing production goal by income level in the Regional Housing Needs Assessment (RHNA). SB 35 requires localities to report their housing production by income level in their annual housing element progress reports (APRs). The units produced are compared to the RHNA targets at the halfway point and end of each cycle. If the locality does not meet its prorated RHNA goals, then certain projects can use a streamlined approval process over the next half -cycle. In order to use Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 12 Page 216 of 328 the streamlined approval process, one of the criteria is that the development must follow all local objective zoning and design standards. SB 6: This bill, the Middle Class Housing Act of 2022, deems a housing development project an allowable use on a parcel that is within a zone where office, retail, or parking are a principally permitted use, if specified conditions are met, including meeting ODS. AB 2011: This bill, the Affordable Housing and High Road Jobs Act of 2022, authorizes a development proponent to submit an application for a housing development that meets specified objective standards and affordability and site criteria, and makes the development a use by right and subject to one of two streamlined, ministerial review processes. In order to use the streamlined, ministerial review process, the development proposal must meet objective development standards. 2.5 APPLICABILITY OF ODS The proposed project would apply to construction projects located anywhere in the City involving the development or substantial improvement of any of the following: 1. Multifamily residential projects, including duplexes, townhouses, or multifamily dwellings. 2. Mixed -use projects featuring a combination of multifamily residential and other uses. The proposed project would apply to any substantial improvement of existing multifamily or mixed - use development where any extension, repair, reconstruction, or other improvement of a property, the cost of which equals or exceeds 50 percent of the fair market value or assessed value of a property either before the improvement started or, if the property has been damaged, before the damage occurred. Any and all additions to buildings for which these standards are applicable shall match the style and details of the main structure. Single-family homes and development with no residential component are not subject to the ODS. The ODS are to be used during the City's development review process. The City will review all future projects to assure adherence to the ODS. 2.6 GOALS AND OBJECTIVES The ODS include the following six goals: • Goal 1: Comply with state mandates to implement new ODS for eligible multifamily housing and mixed -use development projects. • Goal 2: Ensure that appropriate ODS are in place for housing development projects eligible for streamlined ministerial review pursuant to California Government Code Section 65913.4 and other State laws. • Goal 3: Ensure building placement and frontage along existing or proposed streets reflects the intended character. • Goal 4: Establish architectural standards for larger buildings to mitigate overall mass and ensure visual interest from all public vantage points. • Goal 5: Create human -scaled development that contributes to pedestrian -oriented streets and boulevards in mixed -use zoning districts. • Goal 6: Provide design details and illustrations that are prescriptive and objective. Diamond Bar Objective Design Standards February 2026 Page 13 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 217 of 328 The ODS include the following eight design principles: • Principle 1: Maintain —and in some cases, elevate —architectural variety, integrity, and quality. • Principle 2: Ensure that streets and spaces with high volumes of pedestrian traffic are comfortable, protected from the sun, and visually and physically engaging at the ground level. • Principle 3: Create architectural variation along a block front through diversity of massing, articulation, and architectural detailing. • Principle 4: Animate building edges on the ground floor to create an inviting public realm and pedestrian friendly environment and to support multi -modal development and mobility. • Principle 5: Orient building fagades to frame the streets and other public spaces and to take advantage of natural features, such as sunset, sunrise, mountain views and the like. • Principle 6: Provide graceful transitions between larger -scale format of multifamily structures and adjacent smaller scale single-family housing. • Principle 7: Provide standards such that new buildings can sit comfortably adjacent to existing buildings of varied styles. • Principle 8: Provide off-street parking in surface lots or garages at the rear of buildings so that parking does not dominate the built environment. The proposed project would work in tandem with the General Plan 2040, the City Development Code (Title 22 of the Diamond Bar City Code), and other City standards related to new construction such as stormwater drainage, traffic, hillside development, and so on. The ODS provide a step-by-step process to incorporate its standards into future multifamily and mixed -use developments in the City. Table 1, Step -by -Step Application of ODS, is a generalization of this step-by-step application process (see Appendix A for a detailed description of the application process). TABLE 1 Step -by -Step Application of ODS Chapter in ODS Step/Standard Summary of Standard (Appendix A 1. Determine applicable building type Structure general massing and configuration 2 2. Determine applicable building Building articulation and massing 3 articulation standards 3. Determine applicable frontage type Frontage and relationship to public realm or 4 standards street 4. Check compliance with site and open Regulates functional aspects of building form 5 space standards to create human -scale environment 5. Determine applicable architectural style Architectural style and standards 6 standards The proposed project has been developed to be consistent with the General Plan 2040, as amended. The General Plan 2040 contains objective standards related to development density for all land uses in the City. The standards set forth in the proposed project dictate the bulk, mass, and design of buildings in a more detailed way than the General Plan 2040. All feasible mitigation measures in the Certified EIR apply to the proposed project. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 14 Page 218 of 328 2.7 DISCRETIONARY APPROVALS The proposed project would require amendments to the City Development Code (Title 22 of the Diamond Bar City Code) to incorporate the ODS. 2.8 CONSTRUCTION Any construction phases, activities, and anticipated construction equipment associated with future buildout would be the same as those described in the Certified EIR as applicable. As with the Certified EIR, any site preparation and construction would be completed in accordance with all federal, State, and City zoning codes and requirements. Future multifamily and mixed -use development or improvements would be subject to project -specific review requirements and compliance with existing regulations. Diamond Bar Objective Design Standards February 2026 Page 15 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 219 of 328 3.0. ENVIRONMENTAL ANALYSIS The analyses contained herein consider whether the Certified EIR analyses remain sufficient or whether the proposed project would result in a new significant impact or a substantial increase in the severity of previously identified significant impacts. This section presents the environmental analysis for each topic addressed in the Certified EIR. Each of the environmental resource areas previously analyzed in the Certified EIR is addressed with updates that reflect changes to the State CEQA Guidelines since the time of analysis in the Certified EIR. Specifically, the Cultural Resources, Tribal Cultural Resources, Energy, Greenhouse Gas Emissions, Hazards and Hazardous Materials, and Wildfire sections are evaluated as separate environmental topics. The proposed project shall incorporate and implement all feasible and applicable mitigation measures contained in the Certified EIR. Specific mitigation measures relevant to a particular impact of the proposed project are cited in the same manner as in the Certified EIR and the associated Mitigation Monitoring and Reporting Program (MMRP; Appendix B).5 5 City of Diamond Bar. November 2019. Mitigation Monitoring & Reporting Program for the City Of Diamond Bar General Plan 2040 And Climate Action Plan 2040 Environmental Impact Report. SCH No. 2018051066. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 16 Page 220 of 328 3.1 AESTHETICS This section evaluates the effects on aesthetics from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.1, Aesthetics, of the Certified EIR. Potential impacts to aesthetics from the proposed project are discussed relative to the conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant impacts with regard to the following: the existing visual character (including the visual quality of the project site and surroundings), scenic vistas, and new source of substantial light or glare which would adversely affect day or nighttime views in the area. The Certified EIR stated that General Plan 2040 would have no impact on state scenic highways. Pursuant to State CEQA Guidelines Section 15164, this analysis determines whether the proposed project would result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to aesthetics compared to the Certified EIR. 3.1.1 Setting The physical and regulatory environmental setting for aesthetics is the same as described in the Certified EIR. The proposed project would not alter the physical or regulatory conditions described in the Certified EIR. 3.1.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to aesthetics was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines. Would the project: (a) Except as provided in Public Resources Code Section 21099, would the proposed project have a substantial adverse effect on a scenic vista? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to scenic vistas. The proposed project would set new minimum design standards for future multifamily and mixed -use development throughout the City (see Section 2.2). The Certified EIR determined that the General Plan 2040 would continue to regulate development in open spaces, local hillsides and ridges, and distant views of the San Gabriel Mountain Range and enforce policies to ensure that opportunities to enjoy scenic views are either preserved or enhanced. The proposed project primarily focuses on improving the quality of the visual experience for future development (e.g., through high -quality materials and architectural articulation) but would not increase building height or intensity beyond the limits set by the underlying zoning and land use designations. Furthermore, the proposed project would not introduce any new mechanism for obstructing scenic vistas or viewsheds beyond what was already considered in the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on scenic vistas. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 17 Page 221 of 328 (b) Except as provided in Public Resources Code Section 21099, would the proposed project substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to scenic resources, including those within a state scenic highway. The proposed project is an implementing regulatory tool that applies to future construction and does not change the physical location of designated state scenic highways or the protection status of adjacent scenic resources, such as protected trees (as discussed in Section 3.3, Biological Resources) or historic buildings (see Section 3.4, Cultural Resources). The Certified EIR states there are no adopted State scenic highways located in the City. However, the portion of SR-57 adjacent to the western boundary of the City's Sphere of Influence and from the City limits to SR- 57's confluence with SR-60 is eligible for official scenic highway status. As discussed in the Certified EIR, the General Plan 2040's land use changes along this portion of SR-57 are minimal, given that these portions of the highway are adjacent to developed areas and views would not be obstructed. Furthermore, the proposed project promotes a more visually appealing built environment that minimizes the visual distraction of substandard development near scenic areas. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on scenic resources within a state scenic highway. (c) Except as provided in Public Resources Code Section 21099, would the proposed project, in nonurbanized areas, substantially degrade the existing visual character or quality of public views of the site and its surroundings? (Public views are those that are experienced from publicly accessible vantage point). If the proposed project is in an urbanized area, would the project conflict with applicable zoning and other regulations governing scenic quality? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to potential conflicts with applicable zoning and other regulations governing scenic quality in an urban area. The ODS is intended to achieve the design goals set forth in the General Plan 2040. The ODS is intended to ensure visual quality enhancement by setting specific, objective standards for architectural management. For instance, the Building Articulation Standards (Section 3 of the ODS) include measures such as the "Vertical Plane Break" to reduce building bulk and monotony, while the definition of Frontage Types (Section 4 of the ODS) ensures that buildings are constructed with a positive, human -scale relationship to the public streetscape (Appendix A). These standards support high quality street -facing facades and material durability. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on scenic quality in an urban area. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 18 Page 222 of 328 (d) Except as provided in Public Resources Code Section 21099, would the proposed project create new sources of substantial light or glare which would adversely affect day or nighttime views in the area? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to light and glare. The Certified EIR analyzed the potential increase in light and glare associated with the overall planned development and concluded that future development resulting from the General Plan 2040 would necessitate the use of additional light fixtures, such as residential and non-residential interior and exterior lighting, parking lot lighting, commercial signage lighting, lamps for streetscape and public recreation areas. The proposed project would reduce potential future light and glare by providing specific standards, such as prohibiting highly reflective window glazing and requiring compliance with Section 22.16.050 (Exterior Lighting) of the Diamond Bar City Code. Future development guided by the proposed project would be subject to standards that include the placement, shielding, and intensity of outdoor lighting (e.g., mandatory use of downward -facing, fully shielded light fixtures to prevent light spillover onto adjacent properties) and material selection (e.g., limitations on the use of highly reflective materials, such as mirrored glass, to control solar glare). Also, the Diamond Bar City Code contains provisions that would limit the light and glare for future residential and non- residential development. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts from new sources of light or glare. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to aesthetics. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new cumulatively considerable aesthetics impacts for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified EIR, impacts on aesthetics would not be cumulatively considerable. Consistent with the findings of the Certified EIR, impacts in relation to aesthetics would not be cumulatively considerable with implementation of the proposed project, when compared to the General Plan 2040. Therefore, the proposed project would not result in any new significant environmental cumulative impacts or a substantial increase in the severity of previously identified significant cumulative impacts related to aesthetics. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 19 Page 223 of 328 3.2 AIR QUALITY This section evaluates the effects on air quality from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.2, Air Quality, of the Certified EIR. Potential impacts to air quality from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in significant and unavoidable air quality impacts. In addition, mitigation measures for construction and future development would be required, in conjunction with future project approvals, to reduce cumulative impacts of a considerable net increase of criteria pollutants (for which the region is in non -attainment under an applicable federal or state ambient air quality standards), and exposure of sensitive receptors to substantial pollutant concentrations. Consistent with the Certified EIR, air quality for the proposed project was evaluated with regard to the General Plan 2040, the South Coast Air Quality Control District (SCAQMD) significance thresholds, the California Ambient Air Quality Standards (CAAQS), and the National Ambient Air Quality Standards (NAAQS). A review of available records and literature determined that no new air quality information has become available since the certification of the EIR. 3.2.1 Setting The environmental setting for air quality is functionally the same as described in the Certified EIR. Data on existing air quality in the South Coast Air Basin (SCAB), where the proposed project is located, are collected by a network of air monitoring stations operated by the California Air Resources Board (CARB). The regulatory framework plans pertaining to air quality have been updated at the regional level since the preparation of the Certified EIR, including updates to the SCAQMD Air Quality Management Plan (AQMP) and the Southern California Association of Governments (SCAG) Regional Transportation Plan/Sustainable Communities Strategy (Connect SoCal). The 2022 AQMP is the most recent version of the AQMP. When compared to the 2012 and 2016 AQMPs discussed in the Certified EIR, the 2022 AQMP focuses on updates related to the attainment of the 2015 8-hour ozone standard, introduces new control measures that primarily emphasize stationary sources, and newer modeling techniques. In addition, the 2024 Connect SoCal is the most recent Regional Transportation Plan/Sustainable Communities Strategy prepared by SCAG.6 When compared to the 2016 Regional Transportation Plan/Sustainable Communities Strategy discussed in the Certified EIR, the 2024 Connect SoCal provides new focus areas for equity, resilience, and housing; addresses new challenges; and details strategies for mobility, communities, the environment, and the economy. While these regional plan updates are reviewed for consistency, they would not result in substantial changes to the regional framework analyzed under air quality and would not result in changes to the findings in the Certified EIR. Federal, state, and local regulations remain unchanged when compared to the Certified EIR. The Environmental Protection Agency (EPA), CARB, and the local air districts classify an area as attainment, unclassified, or nonattainment depending on whether or not the monitored ambient air quality data shows compliance, insufficient data available, or noncompliance with the ambient air quality standards, respectively. The NAAQS and CAAQS relevant to the proposed project include the following criteria pollutants: ozone, fine particulate matter with an aerodynamic 6 Southern California Association of Governments. 2024. Connect SoCal: A Plan for Navigating to a Brighter Future. https://scag.ca.gov/sites/default/files/2024-05/23-2987-connect-socal-2024-final-complete-040424.pdf (accessed October 30, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 20 Page 224 of 328 diameter of 10 microns in size or less (PM,o), fine particulate matter with an aerodynamic diameter of 2.5 microns in size or less (PM2.5), carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (S02). These standards, along with regional thresholds of significance, are regulated and enforced by SCAQMD in the City. Compared to the NAAQS, the Los Angeles County portion of the SCAB is a nonattainment area for 1-hour ozone, 8-hour ozone, PM2.5, and lead for near - source monitors! Designations for attainment are determined from the ambient air quality. Compared to the CAAQS, the Los Angeles County portion of the SCAB is a nonattainment area for 1-hour ozone, 8-hour ozone, PM2.5, and PM10.8 3.2.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to air quality was evaluated in relation to the following questions as stated in Appendix G of the 2025 State CEQA Guidelines: (a) Would the proposed project conflict with or obstruct implementation of the applicable air quality plan? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to conflicts with or the obstruction of implementation of the applicable air quality plan. The proposed project would set new minimum design standards for future multifamily and mixed -use development throughout the City (please see Section 2, Project Description). In addition, the use of the proposed project on future multifamily and mixed -use development would be subject to project -specific development review requirements and compliance with existing regulations that focus on improving air quality, including the SCAQMD rules and regulations, the General Plan 2040 goals and policies for air quality, and SCAG's Connect SoCal. New development would be subject to compliance with the most recent AQMP and Connect SoCal. The proposed project does not conflict with the most recent updates to these air quality plans. With respect to the 2022 AQMP, implementation of objective design standards for multifamily and mixed -use development would not conflict with attainment of the 2015 8-hour ozone standard, control measures for stationary sources, or newer modeling techniques. With respect to the 2024 Connect SoCal, implementation of objective design standards for multifamily and mixed -use development would not conflict with new focus areas for equity, resilience, and housing; nor would it conflict with strategies for mobility, communities, the environment, and the economy. The proposed project would not result in an increase in population, growth, or additional development beyond the Certified EIR buildout; nor would it result in an increase in vehicle miles traveled (VMT). Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to any conflicts with or obstruction of implementation of the applicable air quality plan. U.S. Environmental Protection Agency. 2023. Nonattainment Areas for Criteria Pollutants. https://www.epa.gov/green-book (accessed October 24, 2025). 8 California Air Resources Board. 2022. Area Designations Maps / State Ambient Air Quality Standards. http://www.arb.ca.gov/desig/adm/adm.htm (accessed October 24, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 21 Page 225 of 328 (b) Would the proposed project result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non -attainment under an applicable federal or state ambient air quality standard? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the cumulatively considerable net increase of any criteria pollutant for which the project region is non -attainment under an applicable federal or state ambient air quality standard. The Certified EIR found that the General Plan 2040 would exceed SCAQMD significance thresholds for volatile organic compounds (VOCs) and nitrogen oxides (NOx), and that construction and operational impacts would be significant and unavoidable based on the potential for the General Plan 2040 to result in a cumulatively considerable net increase of a criteria pollutant for which the City is in nonattainment under the NAAQS and CAAQS. Compared to the NAAQS, the Los Angeles County portion of the SCAB is a nonattainment area for 1-hour ozone, 8-hour ozone, PM2.5, and lead for near -source monitors.9 Designations for attainment are determined from the ambient air quality. Compared to the CAAQS, the Los Angeles County portion of the SCAB is a nonattainment area for 1-hour ozone, 8-hour ozone, PM2.5, and PM,o." The application of the proposed project to future multifamily and mixed -use development within the City would be consistent with the construction phases, activities, and anticipated construction equipment outlined in the Certified EIR (please see Section 2). The application of the proposed project to future multifamily housing and mixed -use development would be subject to project - specific development review requirements and compliance with existing regulations that focus on improving air quality. Similar to the Certified EIR, mitigation measures MM-AQ-1 and MM-AQ-2 would apply to any future developments subject to the proposed project and require such future development projects implemented under the General Plan 2040 to demonstrate consistency with SCAQMD construction and operation emissions thresholds. Criteria pollutant construction and operation emissions from the application of the proposed project to future multifamily and mixed -use development would not change the significant and unavoidable impact conclusion from the Certified EIR. Construction and operation emissions would be reduced to the maximum extent practicable with incorporation of mitigation measures, as specified in the Certified EIR. Because the proposed project would not result in additional development beyond the remaining Certified EIR buildout and be subject to mitigation measures MM-AQ-1 and MM-AQ-2, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to a cumulatively considerable net increase of any criteria pollutant for which the project region is non - attainment under an applicable federal or state ambient air quality standard. (c) Would the project expose sensitive receptors to substantial pollutant concentrations? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to exposing sensitive receptors to substantial pollutant concentrations. The Certified EIR found that the General Plan 2040 would expose sensitive receptors to substantial pollutant concentrations and that construction and operational impacts would be significant and unavoidable. According to the General Plan 2040, sensitive receptors 9 U.S. Environmental Protection Agency. 2023. Nonattainment Areas for Criteria Pollutants. https://www.epa.gov/green-book (accessed October 24, 2025). 10 California Air Resources Board. 2022. Area Designations Maps / State Ambient Air Quality Standards. http://www.arb.ca.gov/desig/adm/adm.htm (accessed October 24, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 22 Page 226 of 328 include residences, hospitals, schools, daycare facilities, playgrounds, parks and other recreational facilities, elderly housing, and other medical care facilities." Construction and operation emissions associated with the application of the proposed project to future multifamily housing and mixed -use development could impact sensitive receptors in the City. While future individual development projects would require separate environmental assessments, the proposed project would be consistent with the construction phases, activities, and anticipated construction equipment outlined in the Certified EIR (see Section 2.5). As with the Certified EIR, development projects subject to the proposed project would also be subject to mitigation measure MM-AQ-1 to reduce impacts on sensitive receptors to substantial pollutant concentrations, which includes reducing toxic air contaminants and health impacts through a reduction of criteria pollutant emissions from the use of more efficient construction equipment. Because the proposed project would not result in any additional development beyond the remaining Certified EIR buildout and any development subject to the proposed project would be also be subject to mitigation measure MM-AQ-1, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to the exposure of sensitive receptors to substantial pollutant concentrations. (d) Would the proposed project result in other emissions (such as those leading to odors) adversely affecting a substantial number of people? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to other emissions (such as those leading to odors) adversely affecting a substantial number of people. The Certified EIR found that the General Plan 2040 would result in significant and unavoidable impacts on air quality in relation to other emissions adversely affecting a substantial number of people, including regional emissions for CO. No mitigation measures were identified in the Certified EIR. With respect to odors during construction and operation, the Certified EIR determined that impacts would be less than significant. The SCAQMD CEQA Air Quality Handbook defines potential odor issues that generally occur from the following land uses: wastewater treatment plants, food processing plants, agricultural uses, chemical plants, composting, refineries, landfills, dairies, and fiberglass moldings. The proposed project merely regulates visual design and would set new minimum design standards for future multifamily and mixed -use development throughout the City (see Section 2.2). None of the land uses stated in the SCAQMD CEQA Air Quality Handbook would apply to future multifamily and mixed -use development. Compared to the General Plan 2040, the proposed project's land uses are consistent with the proposed land uses previously evaluated. As discussed, future multifamily and mixed -use development subject to the proposed project would also be subject to project - specific development review requirements and compliance with existing regulations that focus on improving air quality, including the SCAQMD rules and regulations. Examples of applicable SCAQMD rules and regulations include Rule 402, Nuisance, to avoid causing injury to adjacent sensitive receptors; and Rule 1113 for controlling VOC emissions from the application of architectural coatings. Because the proposed project would not result in additional development beyond what was analyzed in the Certified EIR, the proposed project would not result in a new significant impact or " City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/DocumentCenter/View/7072/Diamond-Bar-General-Plan-2040?bidId= (accessed October 23, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 23 Page 227 of 328 a substantial increase in the severity of previously identified significant impacts related to other emissions (such as those leading to odors) adversely affecting a substantial number of people. Mitigation Measures As with the Certified EIR, mitigation measures MM-AQ-1 and MM-AQ-2 are required for implementation in order to lessen and/or alleviate the impacts related to air quality expected to result from implementation of the proposed project (Appendix B). No further mitigation measures are required. Cumulative Impact Analysis The Certified EIR found that impacts to air quality in relation to long-term regional emissions would be cumulatively considerable. The proposed project is a design overlay that works within the regulatory framework and cumulative growth assumptions of the Certified EIR and is consistent with the analysis of cumulative impacts under the development evaluated in the General Plan 2040. Consistent with the findings of the Certified EIR and analysis above, impacts to air quality from the proposed project in relation to long-term regional emissions would remain cumulatively considerable. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts in relation to air quality. Diamond Bar Objective Design Standards February 2026 Page 24 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 228 of 328 3.3 BIOLOGICAL RESOURCES This section evaluates the potential environmental effects of the proposed project on biological resources. This analysis determines if the proposed project would result in a new significant impact or a substantial increase in the severity of previously identified significant impacts as compared to Section 3.3, Biological Resources, of the Certified EIR. Potential impacts to biological resources from the proposed project are discussed relative to the conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant impacts to biological resources with mitigation incorporated. Mitigation measures for construction and future development would be required in conjunction with future project approvals. Consistent with the Certified EIR, biological resources for the proposed project were evaluated with regard to the State of California Fish and Game Code; the California Native Plant Society (CNPS) online inventory; and the Diamond Bar City Code, Chapter 22.38, Tree Preservation and Protection. 3.3.1 Setting The project setting for biological resources is the same as that considered in the Certified EIR. A review of available records and literature determined that no new biological resources, conservation policies, or ordinances have become available since certification of the EIR. 3.3.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to biological resources was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Wildlife or U.S. Fish and Wildlife Service? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a substantial adverse effect on candidate, sensitive, or special status species. The proposed project would be subject to the existing General Plan policies and the required mitigation measures. The Certified EIR concluded that with the implementation of mitigation measures MM-BI0-1A through MM-1310-11K, the potentially significant impacts on candidate, sensitive, or special status species would be minimized to a less than significant level. The proposed project does not propose new development and would not alter the land use designations and growth projections analyzed in the Certified EIR. The proposed project does not increase the overall development capacity, modify the General Plan land use boundaries, or change the level of intensity that was the basis for the Certified EIR's analysis. The proposed project does not authorize any new ground disturbance or habitat loss beyond the scope of the Certified EIR, which requires project -specific implementation of mitigation measures (MM-BI0-1A through MM-B10-1 K) to avoid or minimize impacts to sensitive species. With adoption of the proposed project, all development that would be subject to the ODS would also be subject to MM- 1310-1A through MM-1310-1 K. As the proposed project would not result in additional development Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 25 Page 229 of 328 or induce growth greater than what was considered in Certified EIR and be subject to mitigation measures MM-BI0-1A through MM-B10-1 K, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to candidate, sensitive, or special status species. (b) Would the proposed project have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Wildlife or U.S. Fish and Wildlife Service? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a substantial adverse effect on any riparian habitat or other sensitive natural community. The proposed project is limited in its application to existing urban corridors within the City. The proposed project is not applicable to the City's open space, canyon, or hillside areas where sensitive natural communities, such as riparian habitats or coastal sage scrub, are typically located. The Certified EIR identified significant impacts to these sensitive communities and adopted comprehensive General Plan policies and mitigation measures MM- 1310-2 through MM-BIO-5 that prohibit or heavily restrict development within these areas. The Certified EIR concluded that with the implementation of these measures, the potentially significant impacts on sensitive natural communities, including oak woodlands, walnut woodlands, riparian, and sage scrub habitats, would be minimized to a less than significant level. With the adoption of the proposed project, all development that would be subject to the ODS would also be subject to MM-1310-2 through MM-BIO-5. Given that the proposed project is a set of design standards and does not facilitate or authorize new development in biologically sensitive locations, the proposed project would not introduce a new or increased level of impact to these protected communities. The proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to potential impacts on riparian habitat or other sensitive natural communities. (c) Would the proposed project have a substantial adverse effect on state or federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a substantial adverse effect on state or federally protected wetlands. The proposed project would be subject to the full regulatory framework and the required site -specific mitigation process applicable to state or federally protected wetlands. The Certified EIR identifies the potential for extensive wetland areas, such as those extending upstream from Arnold Reservoir north of Grand Avenue in the Tres Hermanos portion of the City, to be impacted by the General Plan 2040. The Certified EIR also identified potential impacts to the bed and banks of creeks and their tributaries. However, the Certified EIR explicitly concluded that the implementation of General Plan policies (e.g., LU-P-2, LU-P-56, RC-P-25, RC-P-26) and the application of mitigation measures MM-BIO-2 and MM-BIO-3 would ensure that impacts on federally and state protected wetlands are reduced to a less than significant level. These mitigation measures ensure that any unavoidable loss of jurisdictional features is fully compensated for and approved under the purview of state and federal resource agencies. With the adoption of the proposed project, all development that would be subject to the ODS would also be subject to MM-BIO-2 and MM-BIO-3. The proposed project does not change the physical environment, the regulatory requirements, or the mandatory mitigation measures imposed on future development. Therefore, the proposed project would not result in a new significant impact Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 26 Page 230 of 328 or a substantial increase in the severity of previously identified significant impacts related to state or federally protected wetlands. (d) Would the proposed project interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to interfering with the movement of any native resident or migratory fish or wildlife species; interfering with established native resident or migratory wildlife corridors; or impeding the use of native wildlife nursery sites. The proposed project, developed under the provisions of the General Plan 2040, is consistent with the impacts and mitigation identified in the Certified EIR. The Certified EIR found impacts to wildlife movement to be potentially significant before mitigation. The Certified EIR determined that impacts to wildlife movement would be reduced through consistency with General Plan policies for Open Space and Resource Conservation (specifically referencing RC-P-1, RC-P-9, RC-P-12, and RC-P-24), which address maintenance of the Chino Hills (east) and the Puente Hills (west) wildlife movement corridors and local corridors. The Certified EIR determined that compliance with mitigation measure MM-BIO-6 for the Tonner Canyon wildlife corridor and adherence to General Plan 2040 policies would reduce impacts on wildlife movement to a less than significant level. The proposed project would not change the land use, density, or physical boundaries near these critical corridors; therefore, it would not introduce new barriers or increase fragmentation, and it would not introduce new incompatible land uses next to wildlife movement corridors. Furthermore, the proposed project would not apply to development in open space areas or other areas anticipated to contain wildlife corridors, as the development subject to the proposed project is located on parcels designated for multifamily residential housing and mixed -use. With the adoption of the proposed project, all development that would be subject to the ODS would also be subject to MM-BIO-6. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to wildlife movement. (e) Would the proposed project conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to local biological resource protection policies, such as tree preservation policies or ordinances. The Certified EIR determined that due to regulatory compliance with existing policies, the City Tree Preservation Ordinance and the Los Angeles County Oak Tree Protection Ordinance, no significant impacts would occur, and no mitigation measures were required. Similar to the Certified EIR, the proposed project would be required to comply with the City of Diamond Bar Tree Preservation Ordinance and the Los Angeles County Oak Tree Protection Ordinance. Furthermore, the proposed project includes a provision that actively supports the goals of local greening policies by requiring that "at least 25 percent of the required on -site outdoor space shall be planted with ground cover, shrubs, trees, or a combination thereof." This mandatory landscaping requirement reinforces the City's commitment to enhancing the urban canopy and ensuring biological compatibility within development standards. All future projects subject to the proposed project would be required to obtain necessary permits and comply with all applicable sections of the Diamond Bar Development Code, which includes the City Tree Preservation Ordinance. Therefore, the proposed project would not result in a new Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 27 Page 231 of 328 significant impact or a substantial increase in the severity of previously identified significant impacts related to local policies or ordinances protecting biological resources. (fJ Would the proposed project conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a conflict with an adopted conservation plan. The Certified EIR found that the General Plan 2040 would result in potential conflicts with the Puente -Chino Hills Wildlife Corridor Conservation Program led by the Wildlife Corridor Conservation Authority (WCCA). The EIR concluded that compliance with the adopted General Plan policies and mitigation measure MM-1310-6 would reduce impacts below the level of significance. The proposed project specifies the aesthetic and functional design of buildings and sites within areas already designated for development. The proposed project does not alter the underlying commitment to comply with the terms of any adopted or future Habitat Conservation Plan (HCP) or Natural Community Conservation Plan (NCCP). The adoption of the proposed project would not create a conflict with the provisions of any adopted habitat conservation plan and would be consistent with the scope of impact analyzed in the Certified EIR. Furthermore, the proposed project would not apply to development in open space areas or other areas anticipated to be subject to the Puente -Chino Hills Wildlife Corridor Conservation Program, as the development subject to the proposed project is located on parcels designated for multifamily residential housing and mixed -use. However, if any future projects subject to the proposed project are located within the Puente -Chino Hills Wildlife Corridor Conservation Program area, they would be required to implement the General Plan 2040 policies and MM-BIO-6. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to local, regional, or state habitat conservation plans. Mitigation Measures As with the Certified EIR, mitigation measures MM-1310-1 through MM-BIO-6 are required for implementation in order to lessen and/or alleviate the impacts related to biological resources expected to result from implementation of the proposed project (Appendix B). No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to biological resources for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified El R, the General Plan 2040 would contribute incrementally to the continuing reduction in relatively natural, undisturbed open space areas and contribute to the progressive fragmentation of habitat areas and decline in species diversity throughout the region; however, overall cumulative impacts were determined to be less than significant with incorporation of mitigation measures MM-1310-1 through MM-BIO-6. Consistent with the findings of the Certified EIR, cumulative impacts to biological resources would remain less than significant with implementation of the proposed project, when compared to the General Plan 2040. The proposed project is constrained by the land use and environmental parameters already established and analyzed in the Certified EIR. The proposed project would not propose new development, increase development intensity, or alter the location of planned development. The contribution of development subject to the Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 28 Page 232 of 328 proposed project to the regional cumulative effect is consistent with the scope previously evaluated and mitigated in the Certified EIR. Therefore, the proposed project would not contribute to incremental cumulative biological resource impacts greater than the contribution analyzed in the Certified EIR with the application of standard regulatory compliance and existing mitigation measures. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to biological resources. Diamond Bar Objective Design Standards February 2026 Page 29 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 233 of 328 3.4 CULTURAL RESOURCES This section evaluates the potential environmental effects of the proposed project on cultural resources. This Addendum relies on and incorporates by reference the project and regulatory setting as described in Section 3.4, Cultural, Historic, and Tribal Cultural Resources, of the Certified EIR. Potential impacts to cultural resources from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in significant and unavoidable impacts to historical resources, less than significant impacts with mitigation to archaeological resources, and less than significant impacts to human remains. Mitigation measures for construction and future development would be required in conjunction with future project approvals. 3.4.1 Setting The environmental setting for cultural resources is consistent with what was described in the Certified EIR. The historic setting, historical resources, archaeological resources, and data available for the presence of human remains are the same for the proposed project as those described in the Certified EIR. The regulatory setting applicable to cultural resources presented in the Certified EIR, including the National Historic Preservation Act, National Register of Historic Places, California Register of Historic Resources, and all applicable federal, state, and local regulations are the same and apply to the proposed project. 3.4.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on historical resources was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project cause a substantial adverse change in the significance of a historical resource pursuant to §15064.5? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to historical resources. The Certified EIR determined that impacts would be significant and unavoidable, as anticipated development in the City could result in a substantial change in the significance of a historical resource through physical demolition, destruction, relocation, or alteration of the resource. Consistent with the Certified EIR, future development subject to the proposed project would continue to be subject to mitigation measure MM-CULT-1. With the implementation of MM-CULT- 1, impacts to historical resources would be reduced; however, the impact would remain significant because historical resources could be demolished or altered in a manner such that they are no longer able to convey their historical significance. All future development subject to the proposed project was considered in the Certified EIR. As the proposed project would not result in additional development beyond what was considered in the Certified El R, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to historical resources as defined in State CEQA Guidelines Section 15064.5. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 30 Page 234 of 328 (b) Would the proposed project cause a substantial adverse change in the significance of an archaeological resource pursuant to § 15064.5? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to archaeological resources. The Certified EIR determined that impacts would be less than significant with mitigation measure MM-CULT-2 incorporated, as future development anticipated by the General Plan 2040 would include construction -related ground disturbance that could disturb previously unknown prehistoric or historic era archaeological resources. Consistent with the Certified EIR, future development subject to the proposed project would continue to be subject to MM-CULT-2. The proposed project would not result in additional development beyond what was considered in the Certified EIR; therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to archaeological resources as defined in State CEQA Guidelines Section 15064.5. (c) Would the proposed project disturb any human remains, including those interred outside of dedicated cemeteries? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to disturbing human remains. The Certified EIR determined that it is possible that unknown prehistoric or historic era human remains could be encountered during construction -related ground disturbance, but impacts would be less than significant through regulatory compliance. Consistent with the Certified EIR, any human remains encountered would be handled in accordance with California Health and Safety Code Section 7050.5. If the human remains are Native American, they would be handled in accordance with Public Resources Code Section 5097.98. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to human remains. Mitigation Measures As with the Certified EIR, mitigation measures MM-CULT-1 and MM-CULT-2 are required for implementation in order to reduce the impacts related to cultural resources expected to result from implementation of the proposed project (Appendix B). No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to cultural resources for the proposed project that were not previously analyzed in the Certified EIR. As discussed in the Certified EIR, cumulative impacts to historical resources would be significant and the contribution of General Plan 2040 would be cumulatively considerable despite the implementation of mitigation measure MM-CULT-1. With respect to archaeological resources, the Certified EIR determined that the Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 31 Page 235 of 328 cumulative impact would be significant and the contribution of General Plan 2040 would be cumulatively considerable. With respect to human remains, the Certified EIR determined that the cumulative impact would be less than significant. The contribution of the proposed project to the regional cumulative effect is consistent with the scope previously evaluated and mitigated in the Certified EIR. Therefore, the proposed project would not contribute to incremental cumulative cultural resource impacts greater than the contribution analyzed in the Certified EIR for human remains, and the cumulative impact remains less than significant with the application of standard regulatory compliance. The proposed project would not result in additional development beyond what was considered in the Certified EIR; therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified cumulative significant impacts related to cultural resources. Diamond Bar Objective Design Standards February 2026 Page 32 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 236 of 328 3.5 ENERGY This section evaluates the effects on energy from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.5, Energy, Climate Change, and Greenhouse Gases, of the Certified EIR. Potential impacts to energy from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant energy impacts, with no mitigation measures required. Consistent with the Certified EIR, energy for the proposed project was evaluated with regard to the General Plan 2040, Title 24 of the California Green Building Standards (CalGreen), SCAG's Connect SoCal, and the City's Climate Action Plan (CAP). 3.5.1 Setting The project setting for energy is the same as that considered in the Certified EIR. A review of available records and literature determined that new energy information has become available since the certification of the EIR, including (1) an update to Connect SoCal, which includes goals to improve energy efficiency in the region to facilitate sustainable development;12 and (2) required compliance with the California Code of Regulations, including Title 20 Division 2, Chapter 4 (Energy Conservation), and Title 24, Part 6 of the California Energy Code (CEC). These regional plan updates include more stringent energy efficiency goals and regulations, when compared to the regional plans discussed in the Certified EIR. However, the proposed project does not include changes or reductions in energy efficiency or compliance with energy or sustainable development standards that would conflict with applicable energy plans. 3.5.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to energy was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines. (a) Would the proposed project result in potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operations? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to resulting in wasteful, inefficient, or unnecessary consumption of energy resources during project construction or operations. The expenditure of non-renewable resources would be incurred as a result of future design modifications from the proposed project, including electricity, natural gas, propane, diesel, and gasoline. The application of the proposed project to future multifamily and mixed -use development would be subject to project -specific development review requirements and compliance with existing energy -based regulations. Moreover, the proposed project includes functional architectural elements, such as room to accommodate shade structures for townhouses, flex/loft buildings, walk-up flat parking; courtyard 12 Southern California Association of Governments. 2024. Connect SoCal: A Plan for Navigating to a Brighter Future. https://scag.ca.gov/sites/default/files/2024-05/23-2987-connect-socal-2024-final-complete-040424.pdf (accessed October 30, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 33 Page 237 of 328 multi -family buildings, wrap building, urban blocks; and photovoltaic panels for buildings (Appendix A), which would decrease electricity consumption and other non-renewable energy expenditures. Furthermore, there would be no increase in VMT as a result of the proposed project (see Section 3.13, Transportation). Therefore, no additional energy expenditures for vehicular travel would result from the proposed project. The proposed project would not result in additional development or induce growth beyond what was considered in the Certified EIR. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to resulting in wasteful, inefficient, or unnecessary consumption of energy resources during project construction or operations. (b) Would the proposed project conflict with or obstruct a state or local plan for renewable energy or energy efficiency? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to a conflict with or obstruction of a state or local plan for renewable energy or energy efficiency. As with the Certified EIR, the proposed project would result in less than significant impacts in relation to a conflict with or obstruction of a state or local plan for renewable energy or energy efficiency. The application of the proposed project to future multifamily and mixed -use development would be subject to project -specific development review requirements. In addition, the proposed project would be required to comply with existing energy - based regulations, including the General Plan 2040, Title 24 of the California Green Building Standards, SCAG's Connect SoCal, and the City's CAP. Future multifamily and mixed -use development also would be required to comply with energy conservation regulations embedded in California Code of Regulations Title 20, Division 2, Chapter 4; and CCR Title 6. The updates to Connect SoCal and the California Code of Regulations since adoption of the Certified EIR include more stringent energy efficiency goals and regulations, when compared to the regional plans discussed in the Certified EIR, and future development in the City would continue to be subject to these most recent versions. Further, the proposed project does not include changes or reductions in energy efficiency that would conflict with energy or sustainable development standards and, therefore, would not change the findings in the Certified EIR. Additionally, as previously discussed, the proposed project includes functional architectural elements for a variety of building types that would decrease electricity consumption and other non-renewable energy expenditures. The proposed project would not result in additional development beyond what was previously evaluated in the Certified EIR. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts that would conflict with or obstruct a state or local plan for renewable energy or energy efficiency. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to energy. No further mitigation measures are required for the proposed project. Cumulative Impact Analysis The implementation of the proposed project would not result in or contribute to a cumulative energy impact. This proposed project is a design overlay that works within the regulatory framework and cumulative growth assumptions of the Certified EIR and is consistent with the Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 34 Page 238 of 328 analysis of cumulative impacts under the development evaluated in the General Plan 2040. The Certified EIR concluded that the environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operations, conflict with or obstruct a state or local plan for renewable energy or energy efficiency would not be cumulatively considerable. Consistent with the Certified EIR, implementation of the proposed project would not result in cumulatively considerable impacts in relation to energy. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to energy. Diamond Bar Objective Design Standards February 2026 Page 35 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 239 of 328 3.6 GEOLOGY, SOILS, AND SEISMICITY This section evaluates the effects on geology and soils impacts from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.6, Geology, Soils, and Seismicity, of the Certified EIR. Potential impacts to geology and soils from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR concluded that the General Plan 2040 would result in less than significant impacts to geology and soils. Consistent with the Certified EIR, geology and soils for the proposed project were evaluated with regard to the Los Angeles County General Plan Safety element; County of Los Angeles All -Hazard Mitigation Plan, the USGS 7.5-minute series topographic quadrangle; California Division of Mines and Geology (CDMG) publications; the most recent Alquist-Priolo Earthquake Fault Zone (APEFZ) Map; the City of Diamond Bar Natural Hazards Mitigation Plan; published maps; and technical studies. Review of available records and literature determined that no new information has become available since the certification of the Certified EIR. 3.6.1 Setting The project setting for geology and soils remains consistent with the setting considered in the Certified EIR. 3.6.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to hydrology and water quality was evaluated in relation to the following questions in Appendix G of the State CEQA Guidelines. (a) Would the proposed project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving: Rupture of a known earthquake fault, as delineated on the most recent Alquist- Priolo Earthquake Fault Zoning Map, issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the rupture of a known earthquake fault. The Certified EIR established that the project area is not within an Alquist-Priolo Earthquake Fault Zone, and no known active faults transect the area. Therefore, the risk of surface fault rupture is consistently considered very low. Since the proposed project is limited to the design and articulation of the building envelope, the ODS exerts no influence on regional tectonic hazards or the potential for surface rupture. The proposed project would not increase the degree of exposure to this hazard beyond the existing baseline and the General Plan's projections. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding rupture of a known earthquake fault. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 36 Page 240 of 328 ii. Strong seismic ground shaking? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to strong seismic ground shaking. The Certified EIR concluded that impacts from strong seismic ground shaking are less than significant because all new buildings must be constructed in compliance with the California Building Code (CBC), Section 1613, which requires structures to be designed and constructed to resist seismic forces in accordance with the Minimum Design Loads for Buildings and Other Structures (ASCE standards). The proposed project comprises a set of aesthetic, functional, and form -based requirements (e.g., facade articulation, frontage types) that are subordinate to the CBC. Further, structural integrity and seismic design are governed by mandatory project -specific engineering and the CBC and required for all development within the General Plan 2040 inclusive of the proposed project. The proposed project would not compromise the seismic integrity of future development. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding strong seismic ground shaking. iii. Seismic -related ground failure, including liquefaction? The proposed project would not exceed General Plan 2040 assumptions, and would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to seismic -related ground failure, including liquefaction. The Certified EIR identified a risk of liquefaction and lateral spreading in areas underlain with loose saturated cohesionless soils, notably within valley basins and along major highway corridors. The proposed project is intended to regulate visual design and has no effect on subsurface hydrogeologic conditions or soil mechanics. All future development subject to the proposed project, particularly those within identified liquefaction hazard zones, are mandatorily required to undergo site -specific geotechnical investigations as part of the permitting process. These investigations, in conjunction with the CBC, prescribe specific foundation design, soil stabilization, and ground improvement techniques necessary to mitigate liquefaction risk. The proposed project does not override these critical regulatory requirements. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding strong seismic ground shaking. iv. Landslides? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to landslides. The Certified EIR acknowledged that steep hills (30 percent slope or greater) in the Planning Area are subject to a high risk of seismically induced landslides. However, the impact was determined to be less than significant because all development must address these hazards through site -specific geotechnical studies and conform to the current design provisions of the CBC and General Plan 2040 policies protecting hillside development. The proposed project applies primarily to urbanized and infill areas designated for multifamily and mixed -use development, which are generally located outside the most sensitive steep hillsides. Future development subject to the proposed project that occurs on or adjacent to slopes, the proposed project architectural requirements will not supersede the need for comprehensive geotechnical reporting and the implementation of slope stability measures required by the City Engineer and the CBC. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding landslides. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 37 Page 241 of 328 (b) Would the proposed project result in substantial soil erosion or the loss of topsoil? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial soil erosion or the loss of topsoil. The Certified EIR concluded that development under the General Plan 2040 could expose soils to erosion during earthwork activities. However, the impact was found to be less than significant due to mandatory compliance with the National Pollutant Discharge Elimination System (NPDES) permit requirements for projects disturbing over one acre, which includes the implementation of a Storm Water Pollution Prevention Plan (SWPPP) and Best Management Practices (BMPs). Additionally, General Plan 2040 policies RC-P-24 and RC-P-26 specifically require these measures to control erosion and sedimentation during and after construction. The proposed project would not expand the total area of land disturbance; nor would it increase the overall development capacity of the City beyond the levels analyzed in the Certified EIR. Future development (new multifamily and mixed -use buildings) subject to the proposed project remain fully subject to all mandatory federal, state, and local regulations related to water quality and soil protection, including the requirements for NPDES permits, SWPPPs, and BMPs. While the proposed project influences exterior elements like landscaping and courtyards, the critical engineering aspects of site preparation, grading, and permanent drainage control are governed by the City Engineer and mandatory grading permits, which prioritize erosion control. The proposed project will not compromise the mandatory regulatory framework that prevents substantial soil erosion and loss of topsoil. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding substantial soil erosion or the loss of topsoil. (c) Would the proposed project be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off -site landslide, lateral spreading, subsidence, liquefaction or collapse? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to unstable geologic units or soils. The Certified EIR concluded that areas with unstable underlying materials (undocumented fills, soft compressible deposits, expansive soils) exist within the proposed project area, particularly in areas of hilly terrain and near valley basins. However, the EIR determined that the potential for adverse impacts from geologic hazards (landslide, lateral spreading, subsidence, liquefaction, or collapse) was less than significant for the General Plan 2040 buildout due to the integration of geotechnical requirements into the planning and design process. Since all future development remains fully subject to the strict regulatory framework and policies designed to eliminate risks associated with unstable soils and geologic units, the proposed project does not introduce any new mechanism that would destabilize soils or increase exposure to these hazards. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding unstable geologic units or soils resulting in landslide, lateral spreading, subsidence, liquefaction or collapse. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 38 Page 242 of 328 (d) Would the proposed project be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial direct or indirect risks to life or property? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to expansive soils. The Certified El R acknowledged that areas within the Planning Area contain soils with expansive properties, which swell and shrink with changes in moisture content, potentially causing damage to foundations, pavements, and utility lines, thereby creating risks to life or property. However, the Certified EIR concluded this impact was less than significant. The proposed project comprises a set of architectural and aesthetic design criteria and is entirely unrelated to subsurface soil mechanics, geotechnical engineering, or structural foundation design. The proposed project would not authorize any development that would be exempt from the mandatory requirements for site -specific geotechnical investigation and mitigation measures enforced by the City Engineer and the CBC. Therefore, the proposed project would not introduce any new risks to life or property in areas of the City that may contain expansive soils. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to expansive soil hazards. (e) Would the proposed project have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for disposal of waste water? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the capability of soils to support septic systems. The Certified EIR indicated that the General Plan 2040 and the overall project area are already served by extensive public sewer infrastructure, provided by various agencies including the Sanitation Districts of Los Angeles County. The General Plan 2040's anticipated growth, which is the maximum potential growth accommodated by the proposed project, is based on the assumption that all new development will connect to and utilize the existing and planned public wastewater conveyance and treatment facilities. The proposed project applies to multifamily and mixed -use infill development within the urbanized areas of the City, which are already fully serviced by public sewers. There are no anticipated instances where future development subject to the proposed project would rely on septic tanks or alternative on -site wastewater disposal systems. Furthermore, the proposed project is a design standard and has no bearing on the presence, functionality, or capacity of public sewer systems or the use of private disposal systems. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts as it relates to the capacity of soils to support septic or alternative wastewater disposal systems. (1 J Would the proposed project directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the destruction of unique paleontological or geologic resources. The Certified EIR concluded that, while the Planning Area contains underlying geologic formations (such as the Fernando Formation) known to contain paleontological resources and includes potentially unique geologic features (like steep hillsides), the potential for destruction was Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 39 Page 243 of 328 determined to be less than significant due to mandatory regulatory compliance and mitigation measures MM-GEO-1 and MM-GEO-2. The proposed project does not determine the extent of ground disturbance or excavation depth, which are the primary factors leading to the destruction of these resources. The amount of earthwork is dictated by the maximum density and intensity of the General Plan 2040. Furthermore, all future development subject to the proposed project is required to abide by the appropriate regulatory requirements, including the cessation of earth - moving activity if potential resources are discovered, and the mandatory recovery and preservation of any unique paleontological resources in accordance with the Los Angeles County Paleontological Resource Assessment and Guidelines. Since the proposed project must adhere to existing General Plan policies and protocols for resource discovery and preservation, the proposed project does not introduce any new significant risks that would destroy a unique resource. However, consistent with the Certified EIR, all development subject to the proposed project would continue to implement mitigation measures MM-GEO-1 and MM-GEO-2 to ensure that impacts to paleontological resources would be less than significant. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts that would directly or indirectly cause the destruction of a unique paleontological resource or site or unique geologic feature. Mitigation Measures As with the Certified EIR, mitigation measures MM-GEO-1 and MM-GEO-2 are required for implementation in order to lessen and/or alleviate the impacts related to paleontological resources expected to result from implementation of the proposed project (Appendix B). No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to geology and soils for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified EIR, cumulative increases in population and development that would result from the implementation of the full buildout of the General Plan 2040 would increase the number of residents and employees exposed to the region's known seismic hazards; however, conformance with the CBC and proposed General Plan 2040 policies would preserve building integrity during a seismic event, and other regulatory measures would reduce geohazards impacts to below the level of significance. As a result, cumulative impacts would be minimized and less than significant. Consistent with the Certified EIR, the proposed project would not result in a significant adverse cumulative impact to geology and soils as the proposed project is strictly an architectural and functional design overlay. In addition, the proposed project does not increase underlying development capacity, nor does it override mandatory safety regulations. All future development, regardless of ODS requirements, is obligated to follow the CBC and requires site -specific geotechnical investigations to mitigate risks from seismic shaking, liquefaction, landslides, and expansive soils. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to geology and soils. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 40 Page 244 of 328 3.7 GREENHOUSE GAS EMISSIONS This section evaluates the effects on greenhouse gas (GHG) emissions from the proposed project. This Addendum relies on and incorporates by reference the physical setting and regulatory setting as described in Section 3.5, Energy, Climate Change, and Greenhouse Gases, of the Certified EIR. Potential impacts to GHG emissions from the proposed project are discussed relative to the conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant GHG emissions impacts, with no mitigation measures required. Consistent with the Certified EIR, the proposed project was evaluated with regard to the General Plan 2040, the CARB Scoping Plan Update, Executive Orders S-3-05 and B-48-18, SCAG's Connect SoCal, and the City's CAP. 3.7.1 Setting The project setting for GHG emissions is the same as that considered in the Certified EIR. A review of available records and literature determined that new GHG emissions information has become available since the Certified EIR, including (1) a 2024 update to Connect SoCal, which includes a revision from CARB to set more stringent GHG reduction targets for the SCAG region at 8 percent below 2005 per capita emissions levels by 2020 and 19 percent below 2005 per capita emissions levels by 2035,11 and (2) a 2022 update to the CARB Scoping Plan,14 which includes more stringent GHG reduction goals compared to the 2017 Scoping Plan update analyzed in the Certified EIR. While these regional plan updates are reviewed for consistency, the updates to SCAG's Connect SoCal and the CARB Scoping Plan would not result in substantial changes to the regional framework analyzed in the Certified EIR with respect to GHG emissions and, thus, would not result in changes to the findings made in the Certified EIR. 3.7.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to GHG emissions was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to generating direct or indirect GHG emissions that may have a significant impact on the environment. The Certified EIR determined that the General Plan 2040 would result in less than significant impacts. According to AB 32, GHG emissions are defined as emissions of the following gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N20), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). While SCAG's Connect SoCal and the CARB Scoping Plan have been updated since adoption of the 13 Southern California Association of Governments. 2024. Connect SoCal: A Plan for Navigating to a Brighter Future. https://scag.ca.gov/sites/default/files/2024-05/23-2987-connect-socal-2024-final-complete-040424.pdf (accessed November 5, 2025). 14 California Air Resources Board. December 2022. 2022 Scoping Plan for Achieving Carbon Neutrality. https:Hww2.arb.ca.gov/sites/default/files/2023-04/2022-sp.pdf (accessed November 3, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 41 Page 245 of 328 Certified EIR to set more stringent GHG reduction targets, these updates would not change the conclusions of the Certified EIR, and the proposed project would not conflict with the reduction targets. Future development in the City that would be subject to the proposed project would continue to be subject to the most recent versions of SCAG's Connect SoCal and the CARB Scoping Plan to meet the most recent reduction targets. The proposed project is a set of design standards and does not increase development capacity; as such, it would not result in unplanned development in the City beyond the development that was evaluated for GHG emissions in the Certified EIR. As found in the Certified EIR, future multifamily residential and mixed -use development subject to the proposed project would have the potential to emit these GHG emissions from area, energy, and mobile sources. However, there would be no additional development that would increase VMT as a result of the proposed project compared to the Certified EIR (see Section 3.13, Transportation). Thus, no additional GHG emissions from vehicular travel, as measured by VMT, would result from the proposed project. Similarly, the proposed project would not involve area or energy sources that would result in an exceedance in GHG emissions, and no additional development would occur that was not planned in the General Plan 2040 and considered in the Certified EIR. Furthermore, the application of the proposed project to future multifamily and mixed -use development would be subject to project -specific development review requirements and compliance with existing GHG emissions regulations. The proposed project includes a requirement for at least 25 percent of outdoor space to be dedicated to landscaping (e.g., shrubs, cover, and/or trees) for walk-up flats, courtyard multifamily buildings, wrap buildings, and urban blocks, which could provide for an increase in available carbon storage opportunities within the City. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to generating direct or indirect GHG emissions that may have a significant impact on the environment. (b) Would the proposed project conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of greenhouse gases? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to any conflicts with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of greenhouse gases. As with the Certified EIR, the proposed project would result in less than significant impacts. The proposed project would comply with existing energy regulations, including the most recent versions of the General Plan 2040, the CARB Scoping Plan Update, Executive Orders S-3-05 and B-48-18, SCAG's Connect SoCal, and the City's CAP. While SCAG's Connect SoCal and the CARB Scoping Plan have been updated since adoption of the Certified EIR to set more stringent GHG reduction targets, these updates would not change the conclusions of the Certified EIR, and the proposed project would not conflict with the reduction targets. Future development in the City that would be subject to the proposed project would continue to be subject to the most recent versions of SCAG's Connect SoCal and the CARB Scoping Plan to meet the most recent reduction targets. The proposed project is a set of design standards and does not increase development capacity; as such, it would not result in unplanned development in the City beyond the development that was evaluated for GHG emissions in the Certified EIR. The application of the proposed project to future multifamily and mixed -use development would be subject to project -specific development review requirements. The proposed project includes landscaping design standards for a variety of building types which could provide for an increase in available carbon storage opportunities within the City. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 42 Page 246 of 328 The proposed project does not propose new development and would not alter the growth projections analyzed in the Certified EIR. The proposed project also does not increase the overall development capacity or change the level of intensity that was the basis for the Certified EIR analysis. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to conflict with applicable plan, policy, or regulation adopted for the purpose of reducing GHG emissions. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to GHG emissions. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to GHG emissions for the proposed project not previously evaluated in the Certified EIR. The Certified EIR found that the General Plan 2040 would not result in cumulatively considerable impact to the generation of direct or indirect GHG emissions and regarding conflict with goals, policies, and regulations established for reducing GHG emissions. Consistent with the findings of the Certified EIR, implementation of the proposed project would not result in a cumulatively considerable impact on GHG emissions. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts to GHG emissions. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 43 Page 247 of 328 3.8 HAZARDS AND HAZARDOUS MATERIALS This section evaluates the potential impacts associated with hazards and hazardous materials resulting from the proposed project. This Addendum relies on and incorporates by reference the physical setting and regulatory setting as described in Section 3.7, Hazards, Hazardous Materials, and Wildfire, of the Certified EIR. This analysis assesses the potential impacts associated with the use, transport, or disposal of hazardous materials, hazardous materials sites, airport hazards, emergency response planning, and wildfire hazards. Potential impacts are discussed relative to the conclusions in the Certified EIR. 3.8.1 Setting The project setting for hazards and hazardous materials is consistent with that considered in the Certified EIR. The proposed project would not alter the physical or regulatory conditions described in the Certified EIR. 3.8.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to hazards and hazardous materials was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines. (a) Would the proposed project create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the routine transport, use, or disposal of hazardous materials. The Certified EIR analyzed the potential for hazardous materials generation from the construction activities associated with the General Plan 2040. The construction and operation of new multi- family and mixed -use buildings includes the routine use of common hazardous materials such as cleaning agents, landscaping chemicals, vehicle fluids, fuels, oils, and construction related materials. The Certified EIR concluded that the implementation of applicable federal, state, and local regulations and policies would be sufficient to lessen the risk of death, injury, and property loss. The routine use of hazardous materials by the proposed project is limited to materials commonly found in residential and low -intensity commercial settings, such as paints, cleaning agents, and landscape chemicals. Since the proposed project is limited to aesthetic details and architectural goals that require specific exterior finishes or color schemes, the proposed project would not increase the volume of construction, operational hazardous materials, or waste generated beyond what was anticipated and deemed less than significant in the Certified EIR. All handling, storage, and transport of hazardous materials and waste associated with future development remain subject to a robust regulatory framework, including federal, state, and local regulations (e.g., Resource Conservation and Recovery Act, Emergency Planning and Community Right -to -Know Act, Hazardous Materials Transportation Act, California Health and Safety Code, and the Consolidated Fire Code). Compliance with the Hazardous Materials Business Plan (HMBP) for threshold quantities and regulations specifying storage areas designed to prevent accidental Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 44 Page 248 of 328 release and protect against fire or health hazards remains mandatory. Since there are currently no permitted hazardous waste facilities in the City, disposal practices are governed strictly by state and local standards. Furthermore, the Certified EIR noted that the General Plan 2040 includes policies that seek to lessen the risk from transport by minimizing truck traffic through residential areas and promoting safe goods distribution. The transport of hazardous materials is primarily related to General Plan 2040 construction development (fuel deliveries), and the movement of household/commercial hazardous waste would not be affected by the proposed project. Since the proposed project would not result in land use changes or increase traffic volumes beyond the Certified EIR, the proposed project would not increase the number of vehicles transporting materials on highways (SR-57 and SR-60) or local roads. Existing regulations and policies manage the safety risks associated with transport. The proposed project does not introduce new types of hazards, increase the scale of hazardous materials used beyond the General Plan's projections, or override any mandatory federal, state, and local regulations that promote safe handling, storage, and emergency response. The proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to routine transport, use, or disposal of hazardous materials. (b) Would the proposed project create a significant hazard to the public or the environment through reasonably foreseeable upset and accidental conditions involving the release of hazardous materials into the environment? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to the accidental release of hazardous materials. The Certified EIR concluded that, given the existing regulations and programs and the General Plan 2040 policies that address the potential for hazardous materials upsets and promote the ability of emergency services to respond to incidents, impacts associated with the release of hazardous materials into the environment would be less than significant. The potential releases of hazardous materials associated with the proposed project are the same as described in the Certified EIR. The Certified EIR describes new development (housing and mixed -use) could increase the risk of the potential upset of routinely used hazardous materials, such as household cleaners and landscaping chemicals, but these would not be present in sufficient quantities to pose a significant risk to the public and must be used in accordance with all applicable laws and regulations. The implementation of the proposed project does not alter site grading, construction methods, or safety protocols. Therefore, the same potential impacts associated with site contamination that were described in the Certified EIR could occur with the proposed project. Grading, drilling, or excavation at a future development site have the potential to mobilize hazardous materials (if currently present in the soil), which could result in exposure of personnel and other sensitive receptors, such as plants and wildlife, to contaminant levels that could result in short- and long-term health effects. Accidental release from operational and construction activities would be addressed through mandatory regulatory compliance. All future development remains subject to existing regulations regarding storage, transport, and safety protocols designed to prevent accidental releases, and facilities handling hazardous materials are subject to routine inspections by the Los Angeles County Fire Department. Furthermore, construction activities for future development must also adhere to strict protocols regarding the handling and storage of construction related hazardous materials, as well as Occupational Safety and Health Administration (OSHA) worker safety standards. The proposed project is an architectural design guide and has no role in regulating the use, storage, or handling of hazardous Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 45 Page 249 of 328 materials or the remediation of contaminated sites. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to the reasonably foreseeable upset and accidental conditions involving the release of hazardous materials into the environment. (c) Would the proposed project emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one -quarter mile of an existing or proposed school? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the emission of hazardous emissions or the handling of hazardous or acutely hazardous materials, substances, or waste within one -quarter mile of an existing or proposed school. The Certified EIR concluded that the General Plan 2040 would result in less than significant impacts regarding hazardous emissions and materials within one -quarter mile of a school. The Certified EIR conclusion noted that the most intense uses likely to handle acutely hazardous materials (e.g., Light Industrial) are confined to specific areas, with only one school, Walnut Elementary, falling within a quarter mile of such designation. The proposed project would only apply to multifamily and mixed -use projects, meaning it would not increase exposure of students to industrial hazardous materials beyond what was identified in the Certified EIR. The proposed project would not change the type of land uses allowed or intensity the manufacture, use, transport, or disposal of hazardous materials, within one -quarter mile of any of the 14 existing schools identified in the Certified EIR. The allowed land uses remain limited to residential, commercial, or mixed -use, which are generally not substantial emitters or handlers of acutely hazardous waste. The General Plan 2040 has policies in place (e.g., PS-P-26) that prohibit the development of projects anticipated to emit hazardous air emissions or handle extremely hazardous substances within one -quarter mile of a school. The proposed project would not interfere with the Local Hazard Mitigation Plan and Emergency Operations Plan's (EOP) (PS-G- 8) ability to respond to local hazards, including hazardous materials incidents, and to plan for the protection of critical facilities (i.e., schools). Furthermore, the small quantities of routine hazardous materials (household cleaners, paints, etc.) associated with the proposed project would be the same as those considered in the Certified EIR analysis; these types of hazardous materials are not present in sufficient quantities to pose a significant risk to the public or schools and are subject to mandatory state regulations. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to emission of hazardous emissions or handling of hazardous or acutely hazardous materials, substances, or waste within one -quarter mile of an existing or proposed school. (d) Would the proposed project be located on a site which is included on a list of hazardous materials site compiled pursuant to Government Code § 65962.5 and, as a result, would it create a significant hazard to the public or the environment? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to development on designated hazardous materials sites. The Certified EIR acknowledges the existence of numerous sites in the City that are included on the "Cortese List" (Government Code No. 65962.5) or require further investigation (as depicted in Figure 3.7-1 and Table 3.7-1 of the Certified EIR). These sites, often located along major local roadways (e.g., Diamond Bar Boulevard, Grand Avenue, Golden Springs Drive), have experienced releases resulting in soil and groundwater contamination. The Certified EIR Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 46 Page 250 of 328 concluded that, while redevelopment of these sites could potentially pose a hazard, the impact would be less than significant because these sites are strictly regulated by existing federal and state policies and are in various stages of the mandatory cleanup process. The proposed project, which guides architectural and site design elements (e.g., building placement, facade articulation) for future multifamily and mixed -use development, has no influence, jurisdiction, or impact over the environmental cleanup, remediation, or regulatory compliance required for contaminated sites. The proposed project would not change the underlying zone or increase the maximum density or intensity of development allowed on these specific sites. Therefore, the proposed project would not increase the degree of intrusion into contaminated soil or groundwater beyond the scope already anticipated and analyzed by the Certified EIR. Compliance with the established regulatory framework will continue to ensure that impacts related to development on designated hazardous material sites are appropriately addressed. The proposed project is a design standard that would not modify the regulatory or remedial requirements governing Cortese List sites. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to development on designated hazardous materials sites. (e) For a proposed project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the project area? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to airport -related safety hazards or excessive noise for people residing or working in the proposed project area. The Certified EIR concluded that the implementation of the General Plan 2040 would have no impact on an airport -related safety hazard because there is no public airport located within two miles of the City. The closest facility, Brackett Field, is located over six miles away, and its Air Impact Assessment (AIA) area does not overlap with the City. The proposed project would apply to the entire City, which is not located within two miles of a public airport or public use airport. Since the proposed project is entirely outside the relevant airport safety and noise influence zones, the proposed project would not result in a safety hazard or excessive noise for people residing or working in the project area related to airport operations. Consistent with the findings of the Certified EIR, the project would have no impact related to an airport -related safety hazard or excessive noise. Thus, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to airport noise. (fJ Would the proposed project impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to interference with an adopted emergency response plan or emergency evacuation plan. The Certified EIR established that the overall buildout of the General Plan 2040 would result in less than significant impacts to emergency response due to the enforcement of existing regulations and specific General Plan 2040 policies. Compliance with the General Plan 2040's policies regarding emergency access, evacuation route development, and roadway development would ensure that emergency vehicle movement could efficiently access all parts of the planning area. The proposed project is a design guide and would not authorize new infrastructure, change the function of existing roadways, or affect the protocols established Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 47 Page 251 of 328 in the City's adopted emergency plans. The proposed project includes requirements for building placement and parking (e.g., Principle 8: Parking and Vehicle Areas) that seek to place parking at the rear of buildings and prioritize street frontage. These requirements are intended to improve pedestrian experience and visual quality, and they do not supersede the requirements of the Fire Code or the City's Engineering Division. Future multifamily and mixed -use development must still undergo development review to ensure compliance with the Los Angeles County Fire Code and the Diamond Bar Emergency Operations Plan (EOP). This mandatory review dictates minimum driveway widths, turning radii, and fire department access routes necessary for the movement of emergency vehicles. Aesthetic or site design standards in the proposed project cannot be approved if they conflict with minimum fire and emergency access requirements. Future development projects, to which the ODS applies, would still be required to be reviewed by the Los Angeles County Fire Department and other relevant emergency service providers to ensure compliance with all mandatory access, water flow, and life safety standards. The ODS does not modify or interfere with these regulatory mechanisms. The proposed project would not introduce any elements or changes to primary circulation that would physically interfere with designated emergency evacuation routes. Since the ODS is subordinate and works in tandem with the mandatory Fire Code and the City's EOP (General Plan Policy PS-G-8), the proposed project would have no potential to physically interfere with an adopted emergency response or evacuation plans. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to interference with an adopted emergency response plan or emergency evacuation plan. (g) Would the proposed project expose people or structures, either directly or indirectly, to a significant risk of loss, injury or death involving wildland fires? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to wildland fire risk. The Certified EIR assessed wildfire risk for the General Plan 2040 buildout and determined impacts would be less than significant with adherence to regulatory requirements. The proposed project does not include new development or increase the intensity of development beyond the buildout already analyzed in the Certified EIR. The proposed project would likewise not expand the development footprint into areas adjacent to wildlands or Wildland-Urban Interface (WUI) zones. All developments in or near a Very High Fire Hazard Severity Zone (VHFHSZ) must comply with the California Public Resources Code and the Los Angeles County Fire Code, including defensible space, fire-resistant building materials, and fuel modification zones. The ODS has an emphasis on durable, high -quality, and non-combustible exterior materials that provide incidental support for fire -safe building practices, which are mandatory under the California Building Code and Fire Code. The proposed project is limited to urbanized areas; therefore, the proposed project would not expose people or structures to a new or increased risk related to wildland fires beyond the analysis already contained in the Certified EIR. The proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to wildland fire risk. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to hazards and hazardous materials. No further mitigation measures are required. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 48 Page 252 of 328 Cumulative Impact Analysis There are no new circumstances involving new impacts to hazards and hazardous materials for the proposed project that were not previously analyzed in the Certified EIR. The proposed project would result in no new significant cumulative impacts related to hazards and hazardous materials than those disclosed in the Certified EIR. Due to rigorous state and federal regulatory frameworks covering hazardous material handling, site cleanup, and mandatory fire safety compliance, cumulative impacts would be less than significant. Implementation of the proposed project does not conflict with or otherwise negate any existing mandatory hazard reduction policies. Furthermore, the proposed project would not add new physical development or increase the severity of any underlying hazard exposure beyond the baseline established in the Certified EIR. Therefore, the proposed project would not introduce any new types of hazardous activities, result in any additional development, or undermine the protective regulatory environment.. The cumulative impact related to hazards and hazardous materials remains less than significant, consistent with the findings of the Certified EIR. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to hazards and hazardous materials. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 49 Page 253 of 328 3.9 HYDROLOGY AND WATER QUALITY This section discusses the effects on hydrology and water quality from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.8, Hydrology and Water Quality, of the Certified EIR. Potential impacts to hydrology and water quality from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant impacts to hydrology and water quality, with no mitigation measures required. Consistent with the Certified EIR, hydrology and water quality impacts were evaluated in relation to the General Plan 2040, groundwater basin data from the California Department of Water Resources,15 and National Flood Insurance Program Flood Insurance Rate Maps for Los Angeles County.16 3.9.1 Setting The environmental and regulatory setting for Hydrology and Water Quality remains unchanged from that described in the Certified EIR. A review of available records and literature confirms that no new information of importance has been identified since the Certified EIR, including changes to regulations or permitting requirements regulated by the Federal Clean Water Act (CWA), the State Water Resources Control Board, the Construction General Permit (CGP), the Greater Los Angeles County Region Integrated Regional Water Management Plan (GLACR IRWM), or the City of Diamond Bar Water Pollution Control Regulations including the Stormwater and Urban Runoff Pollution Control Ordinance. 3.9.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to hydrology and water quality was evaluated in relation to the following questions in Appendix G of the State CEQA Guidelines. (a) Would the proposed project violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or ground water quality? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the potential violation of water quality standards. The proposed project primarily dictates aesthetic and functional design components (e.g., sense of place, style, details) for specific types of development and substantial improvements, and does not require new construction, operation, or maintenance activities that would deviate from the types of activities, or the associated impacts, already analyzed and addressed in the Certified EIR. As discussed in the Certified EIR, the General Plan 2040 may result in local and temporary impacts related to water quality during construction, but such impacts would be less than significant due to compliance with federal, state, and local water quality regulations and General Plan 2040 policies. The proposed project would not alter the fundamental construction scenario, 15 California Department of Water Resources. 2003. California's Groundwater. Bulletin 118 — Update 2003. 's Federal Emergency Management Agency. 2008. National Flood Insurance Program Flood Insurance Rate Map for Los Angeles County and Incorporated Areas. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 50 Page 254 of 328 scale, or duration of future development; the proposed project establishes ODS for projects that already fall under the scope of the Certified EIR. Consistent with the Certified EIR, to minimize impacts to surface and ground water quality, measures to minimize and contain erosion and sedimentation would be implemented in accordance with the Los Angeles County Grading Code, and a grading permit would be submitted to the County for approval prior to commencement of any construction activities. Furthermore, for projects that disturb more than one acre, compliance with the NPDES General Construction Permit would be required. As required by this permit, future development would develop a SWPPP and comply with any regional requirements to meet State water quality objectives. To prevent hazardous materials from entering drainages and affecting water quality, future development would be required to implement a Hazardous Materials Business Plan and submit it to the Los Angeles County Environmental Health Services Department for review and approval. Though local and temporary water quality impacts are possible during the construction of developments that would be subject to the proposed project, any future development would implement NPDES compliance, which is designed to minimize and mitigate potential impacts, as specified in the Certified EIR. The proposed project would not require construction, operation, or maintenance efforts that were not previously addressed in the Certified EIR. Impacts related to water quality standards or waste discharge requirements are expected to be less than significant as described in the Certified EIR. The City's existing development review process, which would incorporate the proposed ODS checklist, and the mandatory regulatory framework (e.g., NPDES, SWPPP, Grading Code) require future development demonstrate compliance with all required water quality permits prior to commencement of construction activities. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to water quality standards or waste discharge requirements. (b) Would the proposed project substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to groundwater supplies or groundwater recharge. The Certified EIR concluded that the General Plan 2040 would not substantially decrease groundwater supplies or interfere substantially with groundwater recharge, and impacts would be less than significant. The General Plan 2040 contains policies that are specifically designed to support groundwater recharge and conserve groundwater. These policies include the goal of preserving permeable surfaces, ridgelines, and hillsides, which directly aids in maintaining the natural filtration and recharge capabilities of the land. The City's Water Pollution Ordinance and General Plan 2040 policies also aim to protect groundwater from potential sources of contamination, thereby ensuring the quality of the resource. In addition, the Certified EIR noted that groundwater -supplied recycled water could be a potential source for landscape irrigation, reducing potential impacts on imported and surface potable water supplies. The proposed project does not increase the maximum number of dwelling units, building square footage, or site coverage allowed by the existing zoning. Therefore, the proposed project does not increase the City's overall water demand or impervious surface area beyond what was already analyzed in the Certified EIR, nor does it override the City's existing conservation policies. Any increase in new impervious surface would be localized and distributed, constituting a small fraction of the City's overall permeable surface area. The proposed project would not have a measurable effect on groundwater recharge at the basin level. Any small, localized increase in Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 51 Page 255 of 328 runoff would be managed by existing stormwater regulations and Low Impact Design (LID) standards (as discussed in the Certified EIR) and would not result in a significant impact to the overall volume of groundwater recharge. The proposed project would not fundamentally alter the scale of development or the regulatory environment pertaining to water conservation and stormwater management established by the Certified EIR. The proposed project would not introduce new or greater impacts related to groundwater demand or interfere with groundwater recharge beyond the levels previously determined to be less than significant in the Certified EIR. Accordingly, the proposed project would not impede on sustainable groundwater management of the basin, and impacts related to groundwater supplies and recharge remain less than significant. Accordingly, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to groundwater supplies or recharge. (c) Would the proposed project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river or through the addition of impervious surfaces, in a manner which would: Result in a substantial erosion or siltation on- or off -site? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantially altering the existing drainage patterns. The Certified EIR determined that development or redevelopment anticipated by the General Plan 2040 could increase impervious surfaces, such as roofs, patios, driveways, and parking areas and lead to increased stormwater flow, but impacts would be less than significant. The Certified EIR states the majority of development that could occur in the City would be redevelopment of areas with already impervious surfaces and would comply with City ordinances and General Plan 2040 policies that reduce erosion. The proposed project would not change the requirements for all future development disturbing over one acre to develop and implement a SWPPP and comply with the NPDES Construction General Permit. The proposed project does not override any water quality regulatory requirements or alter standard construction practices that are already subject to the Los Angeles County Grading Code. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts from erosion or siltation. ii. Substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off -site? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to surface runoff. The Certified EIR already analyzed the maximum potential increase in impervious surfaces and runoff. The Certified EIR determined that development or redevelopment anticipated by the General Plan 2040 could increase impervious surfaces, such as roofs, patios, driveways, and parking areas and lead to increased stormwater flow, but impacts would be less than significant. The Certified EIR states the majority of development that may occur in the City is redevelopment of areas with already impervious surfaces and would comply with City ordinances and General Plan 2040 policies that reduce runoff. The proposed project applies to development already considered in the Certified EIR; it would not increase the maximum impervious area beyond what was previously considered. Furthermore, post -development runoff is regulated by the MS4 Permit (Order No. R4-2012-0175) and local ordinances, which mandate the incorporation of LID practices to detain, retain, or treat Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 52 Page 256 of 328 runoff and prevent an increase in post -development flow rates that could cause flooding. These practices are designed to manage runoff rate and volume to prevent new flooding, regardless of the architectural style required by the proposed project. For these reasons, impacts associated with the proposed project would be less than significant and the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts from surface runoff that could result in flooding. iii. Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to runoff in excess of stormwater drainage systems. The Certified EIR determined that development or redevelopment anticipated by the General Plan 2040 could increase impervious surfaces, such as roofs, patios, driveways, and parking areas and lead to increased stormwater flow, but impacts would be less than significant. The Certified EIR states the majority of development that may occur in the City is redevelopment of areas with already impervious surfaces and would comply with City ordinances and General Plan 2040 policies that reduce runoff and pollution. Stormwater drainage capacity is managed through adherence to the MS4 Permit's Hydromodification Management requirements which include engineering controls and detention/retention features to ensure that the post -development hydrograph does not substantially exceed the pre -development hydrograph. Polluted runoff is strictly controlled by BMPs required by the MS4 Permit. The ODS requirements in the proposed project, such as providing off-street parking in surface lots or garages at the rear of buildings (Principle 8) or orienting building fagades (Principle 5), relate to site layout but do not introduce new or substantial sources of pollution not previously addressed in the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to existing or planned stormwater draining systems or providing additional sources of polluted runoff. iv. Impede or redirect flood flows? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to impeding or redirecting flood flows. The Certified EIR determined that development or redevelopment anticipated by the General Plan 2040 could change site layouts, but impacts would be less than significant. The Certified EIR states the majority of development that may occur in the City is redevelopment of areas with already impervious surfaces and would comply with City ordinances and General Plan 2040 policies that reduce flood flows. The proposed project does not contain specific mandates for grading or filling that would inherently impede flood flows. Future development in the City must comply with the City's Floodplain Management Ordinance and all required permits, which ensures flood flows are not redirected in a manner that causes off -site impacts. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding flood flows. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 53 Page 257 of 328 (d) In flood hazard, tsunami, or seiche zones, would the proposed project risk release of pollutants due to project inundation? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the potential release of pollutants in flood hazard, tsunami, or seiche zones. The Certified EIR found that impacts would be less than significant because the City is located sufficiently inland to be out of what would be considered a potential hazard area for seiches, tsunamis, and sea level rise. The proposed project would not require or encourage the placement of development or new significant sources of pollutants within high -risk inundation zones that were not already anticipated by the Certified EIR. Any future development subject to the proposed project must comply with state and local regulations for the storage and management of hazardous materials and waste, which minimizes the risk of pollutant release during an inundation event. Future development must comply with all federal, state, and local safety codes, including the preparation and implementation of a Hazardous Materials Business Plan (if required), which ensures that materials are stored to minimize the risk of release during an inundation event. Therefore, the proposed project would result in less than significant impacts regarding the risk of pollutant release due to inundation in flood hazard, tsunami, or seiche zones, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts regarding the risk of pollutant release due to such inundation. (e) Would the proposed project conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a conflict with a water quality control plan or sustainable groundwater management plan. The Certified EIR found that impacts would be less than significant because development would be subject to the RWQCB requirements, the Diamond Bar City Code, and General Plan 2040 policies. Consistent with the Certified EIR, development subject to the proposed project would continue to be subject to those requirements. Future development associated with the proposed project would not conflict with the MS4 Permit (NPDES Permit CAS004001) or the City's Stormwater and Urban Runoff Pollution Control Ordinances. The proposed project must adhere to these mandatory regulatory requirements, including the use of source control, treatment, and LID BMPs. The proposed project would not affect the water demand projections in the General Plan 2040 and would not override the General Plan's policies that are designed to preserve permeable surfaces, reduce impervious areas, and support groundwater recharge. The Certified EIR states the General Plan 2040's goals and policies ensure that water quality is protected to the maximum extent practicable. Thus, the proposed project would not substantially degrade water quality or impede sustainable groundwater management and impacts would be less than significant. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts that would conflict with or obstruct the implementation of a water quality control plan or sustainable groundwater management plan. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to hydrology and water quality. No further mitigation measures are required. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 54 Page 258 of 328 Cumulative Impact Analysis There are no new circumstances involving new impacts to hydrology and water quality for the proposed project that were not previously analyzed in the Certified EIR. The Certified EIR analyzed the cumulative impacts of full buildout under the General Plan 2040, which includes the maximum potential for new impervious surfaces, increased runoff, and associated water quality degradation from anticipated future development and redevelopment in the City. The Certified EIR concluded that the impacts to hydrology and water quality were less than significant because the General Plan 2040 mandates rigorous regulatory compliance. Consistent with the Certified EIR, development subject to the proposed project would continue to be subject to the RWQCB requirements, the Diamond Bar City Code, and General Plan 2040 policies, ensuring that cumulative impacts to hydrology and water quality would remain less than significant with implementation of the proposed project. This conclusion is based on the function of the proposed project as a design overlay that works within the regulatory framework and cumulative growth assumptions of the Certified EIR. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to hydrology and water quality. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 55 Page 259 of 328 3.10 LAND USE AND HOUSING This section evaluates the effects on land use and housing from the proposed project. This Addendum relies on and incorporates by reference a project setting and regulatory setting as described in Section 3.9, Land Use, Population, and Housing, of the Certified EIR. Potential impacts to land use and housing from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that impacts related to the physical division of an established community; conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect; and displacement of substantial numbers of existing people or housing, necessitating the construction or replacement of housing elsewhere, would be less than significant with no mitigation measures required. Consistent with the Certified EIR, land use and housing impacts from the proposed project were evaluated with regard to the General Plan 2040 and Title 22 (Development Code) of the Diamond Bar City Code. 3.10.1 Setting The project setting for land use and housing is the same as that considered in the Certified EIR. However, while the Certified EIR considered the entire City, the study area for the proposed project is established as areas where the General Plan 2040 land use designations allow for multifamily residential and mixed -use development (Figure 1). A review of available records and literature determined that new housing information has become available since certification of the EIR, including the City's adoption of the 2021-2029 Housing Element Update. The 2021-2029 Housing Element Update conducted an analysis of the City's demographic and housing characteristics and subsequently projected housing needs based on the 2021-2029 RHNA. The RHNA is a key requirement for local governments to plan for anticipated growth. The RHNA quantifies the anticipated need for housing within each jurisdiction for the 6th Housing Element cycle extending from July 2021 to October 2029. The RHNA for the 6th cycle was adopted by SCAG in March 2021. The total housing growth need for the City during the 2021-2029 planning period is 2,521 units, distributed by income category (Table 2, 2021-2029 Regional Housing Needs Assessment). TABLE 3.10-1 2021-2029 Regional Housing Needs Assessment Very Low Low Moderate Above Moderate Total 844 434 437 806 2,521 Source: City of Diamond Bar. 2022.2021-2029 Housing Element Update to the Diamond Bar General Plan 2040. 3.10.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to land use and housing was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project physically divide an established community? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 56 Page 260 of 328 significant impacts in relation to physically dividing an established community. The Certified EIR determined that the General Plan 2040 would result in less than significant impacts and would not physically divide any established community. The proposed project would not physically divide the community in the City since the proposed project would only apply toward the design of future multifamily and mixed -use development that is already planned in the General Plan 2040 and considered in the Certified EIR. Furthermore, Principle 4 of the ODS aims to "animate building edges on the ground floor to create an inviting Public Realm and pedestrian friendly environment and to support multi -modal development and mobility," which would make it easier for the community to travel locally within the City. All future development projects subject to the ODS would also be subject to project -specific development review requirements and compliance with existing land use -based regulations that focus on improving land use. The proposed project would not result in additional development or induce growth greater than what was considered in the Certified EIR. Rather, the proposed project would inform the design of future multifamily and mixed -use development that is already planned for within the City. As such, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to physically dividing an established community. (b) Would the proposed project cause a significant environmental impact due to conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to conflict with a land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect. The Certified EIR found that the General Plan 2040 does not conflict with an applicable land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect; and amendments to the Diamond Bar City Code were required for consistency with the General Plan 2040. The Certified EIR concluded that impacts would be less than significant. As discussed in Section 2, Project Description, implementation of the proposed project would require amendments to Title 22 (Development Code) of the Diamond Bar City Code. All future development projects subject to the ODS would also be subject to project -specific development review requirements and compliance with existing land use -based regulations that focus on improving land use. As the proposed project would not result in additional development or induce growth greater than what was considered in the Certified EIR, the project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts that would conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect. (c) Would the proposed project induce substantial unplanned population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to inducing substantial unplanned population growth. The Certified EIR determined that the City would undergo planned population growth through 2040 that was analyzed throughout the Certified EIR, particularly concentrated in four focus areas, including a Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 57 Page 261 of 328 new Town Center and mixed -use neighborhood. The Certified EIR determined that housing growth under the General Plan 2040 would be sufficient to accommodate the associated increase in population. The proposed project would not induce substantial unplanned growth in an area, either directly or indirectly. The proposed project would only apply toward the design of future multifamily and mixed -use development that has been planned for in the General Plan 2040 and considered in the Certified EIR. The proposed project does not propose new development and would not alter the land use designations and growth projections analyzed in the Certified EIR. The proposed project does not increase the overall development capacity, modify the General Plan land use boundaries, or change the level of intensity that was the basis for the Certified EIR's analysis. Additionally, the proposed project would not extend utility infrastructure or extend roads that would support additional housing in new areas of the City. Finally, the proposed project does not include provisions for new businesses or other commercial development that could require a new workforce that would lead to population growth or demand for housing. As the proposed project would not result in additional development or induce growth greater than what was considered in Certified EIR, the project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to the inducement of substantial unplanned population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure). (d) Would the proposed project displace substantial numbers of existing people or housing, necessitating the construction of replacement housing elsewhere? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to displacing people or housing. The Certified EIR found that the General Plan 2040 would result in less than significant impacts and would not displace substantial numbers of people or housing, as it would increase the overall number of dwelling units and incentivize housing development. As with the Certified EIR, the proposed project would result in less than significant impacts in relation to displacing substantial numbers of existing people or housing. The proposed project does not contain any provisions for removal of housing; rather, adoption of ODS would allow the City to utilize existing State legislation options for streamlining housing development. As described in Section 2, Project Description, adoption of ODS encourages streamlined housing production through SB 35, SB 6, and AB 2011. As such, the proposed project would not displace substantial numbers of existing people or housing but, rather, provide a benefit to housing in the community. Therefore, the proposed project would not result in new significant impacts or a substantial increase in the severity of previously identified significant impacts related to displacing substantial numbers of existing people or housing, necessitating the construction or replacement housing elsewhere. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to land use or housing. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to land use or housing for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified EIR, impacts from the physical division of an established community and from conflict with existing Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 58 Page 262 of 328 plans are not cumulative in nature; however, population growth and housing impacts can be cumulative in nature through direct and indirect effects. The Certified EIR determined that the General Plan 2040 would have a less than cumulatively considerable contribution to impacts on land use and housing. As discussed above, there would be no additional development or induce growth greater than what was considered in Certified EIR, and the proposed project would only apply toward the design of future multifamily and mixed -use development that has been planned in the General Plan 2040 and considered in the Certified EIR. Consistent with the findings of the Certified EIR, cumulative impacts to land use and housing would remain less than significant with implementation of the proposed project, when compared to the General Plan 2040. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to land use and housing. Diamond Bar Objective Design Standards February 2026 Page 59 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 263 of 328 3.11 NOISE This section evaluates the potential noise effects from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.10, Noise, of the Certified EIR. Potential impacts are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that implementation of the General Plan 2040 would result in less than significant impacts regarding the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies; and the generation of excessive groundborne vibration or groundborne noise levels. The Certified EIR determined that there would be no impact regarding excessive noise level exposure due to public or private airport proximity. Consistent with the Certified EIR, noise generated from the proposed project was evaluated with regard to the City's General Plan 2040 Noise Element; and Diamond Bar City Code Sections 8.12.530, 8.12.540, 8.12.720, and 8.12.840. Based on a review of established local general plan or noise ordinance, or applicable standards of other agencies covering the project area, the regulatory framework for noise remains consistent with the Certified EIR. 3.11.1 Setting The project setting for noise remains consistent with the setting considered in the Certified EIR. 3.11.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts from noise was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines. (a) Would the proposed project result in generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. The Certified EIR found that impacts from traffic, construction, railway noise would be less than significant, and that stationary noise would be less than significant with adherence to General Plan 2040 policies. The application of the proposed project to future multifamily housing and mixed -use development would be subject to development review requirements and compliance with existing regulations that focus on improving noise, such as those in the City's General Plan 2040 Noise Element; and Diamond Bar City Code Sections 8.12.530, 8.12.540, 8.12.720, and 8.12.840. The proposed project does not propose new development and would not alter the land use designations and growth projections analyzed in the Certified EIR. The proposed project would not increase the overall development capacity or change the level of intensity that was the basis for the Certified EIR's analysis. Therefore, the proposed project would not result in a new significant Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 60 Page 264 of 328 impact or a substantial increase in the severity of previously identified significant impacts related to the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. (b) Would the proposed project result in generation of excessive groundborne vibration or groundborne noise levels? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the generation of excessive groundborne vibration or groundborne noise levels. The application of the ODS to future multifamily and mixed -use development within the City would be consistent with the construction phases, activities, and anticipated construction equipment outlined in the Certified EIR. Any change in construction noise from future multifamily housing and mixed -use development would be, therefore, negligible. Compared to the Certified EIR, there would be no new groundborne vibration and noise during operations as the proposed project would not result in additional development beyond what is analyzed in the Certified EIR. The application of the proposed project to future multifamily housing and mixed -use development would be subject to development review requirements and compliance with existing regulations that focus on reducing noise and vibration. The proposed project does not propose new development and would not alter the land use designations and growth projections analyzed in the Certified EIR. The proposed project would not increase the overall development capacity or change the level of intensity that was the basis for the Certified EIR's analysis. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to an excessive generation of groundborne vibration or groundborne noise levels. (c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a project located within an airport land use plan or within two miles of a public use airport or private airstrip. The Certified EIR confirmed that the City is not located within an airport land use plan or within two miles of a public use airport or private airstrip. The City of La Verne hosts the closest airport, Brackett Field Airport, located approximately 3.5 miles from the northernmost boundary of the City. As the proposed project would not result in additional development beyond the Certified EIR, or result in any new or additional growth within or near an airport land plan or within two miles of a public use airport or private airstrip area, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to excessive noise level exposure due to public or private airport proximity. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 61 Page 265 of 328 Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to noise. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to noise for the proposed project that were not previously analyzed in the Certified EIR. The Certified EIR determined that General Plan 2040 would result in less than significant cumulative impacts regarding the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies; and an excessive generation of groundborne vibration or groundborne noise levels. Consistent with the findings of the Certified EIR, cumulative impacts to noise would remain less than significant with the implementation of the proposed project, as it is a set of design standards that does not contain provisions for additional development beyond what was evaluated in the Certified EIR. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts in relation to noise. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 62 Page 266 of 328 3.12 PUBLIC FACILITIES AND RECREATION This section evaluates the potential impacts on public facilities and recreation from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section, 3.11, Public Facilities and Recreation, of the Certified EIR. Potential impacts to public services from the proposed project are discussed relative to the conclusions in the Certified EIR. The Certified EIR for the General Plan 2040 concluded that impacts on fire protection, police protection, schools, parks, and other public facilities would be less than significant due to compliance with existing regulations, General Plan policies, and the concentration of growth in areas already served by infrastructure. Consistent with the Certified EIR, public services for the proposed project were evaluated based on a review of the Los Angeles County General Plan, the Los Angeles County Code of Ordinances, and the Los Angeles County Fire Department Fuel Modification Plans and Wildlife Action Plan, the City of Diamond Bar Sheriff's Office, and the websites for the Pomona Unified School District (PUSD) and the Walnut Valley Unified School District (WVUSD). Review of available records and literature determined that no new information of substantial importance was identified that was not known at the time of the certification of the Certified EIR. 3.12.1 Setting The project setting for public services and recreation remain consistent with those considered in the Certified EIR. 3.12.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to public facilities and recreation was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project result in substantial adverse physical impacts associated with the provision of new or physically altered government facilities, need for new or physically altered government facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times, or other performance objectives for any of the public services: Fire protection? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered fire protection facilities. The Certified EIR determined that the anticipated population increase associated with the General Plan 2040 would not necessitate the construction of new fire stations, as new development anticipated by the General Plan 2040 would be efficiently located within three miles of existing stations, and new policies would reduce the need for new facilities. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 63 Page 267 of 328 population or housing units that generate service demand. The proposed project, which sets ODS that regulate building design and site layout (e.g., parking, frontage), is subordinate to the Los Angeles County Fire Code and the City's emergency response protocols. The proposed project must satisfy mandatory requirements regarding building materials, fire flow, and minimum dimensions for emergency vehicle access and turning radius. The proposed project would not compromise the Fire Department's ability to maintain acceptable response times or service ratios. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered fire protection facilities. ii. Police protection? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered police protection facilities. The Certified EIR determined that the anticipated population increase associated with the General Plan 2040 would not necessitate the construction of new police stations, as new development anticipated by the General Plan 2040 would be efficiently located within three miles of existing stations, and new policies would reduce the need for new facilities. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected population or housing units that generate service demand. Therefore, implementation of the proposed project would not result in the need to construct new, or to physically alter existing, police protection facilities to maintain acceptable services. The design elements of the proposed project, such as requirements for enhanced pedestrian visibility, active frontages, and parking placement (Principle 8), could potentially improve Crime Prevention Through Environmental Design (CPTED) principles, which may reduce calls for service in new developments. The proposed project is expected to result in better -designed, safer environments without increasing the demand placed upon the Los Angeles County Sheriff's Department beyond the levels previously determined to be acceptable. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered police protection facilities. iii. Schools? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered school facilities. The Certified EIR's analysis of the Diamond Bar public school system projected a net decline in student enrollment rates between 2017 and 2040, despite the addition of up to 3,264 new housing units. No new school facilities were required. The proposed project applies to multi -family residential and mixed -use units, but it does not increase the total number of units beyond the General Plan's scope. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected population or housing units that generate service demand. Thus, Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 64 Page 268 of 328 the demographic trends in the General Plan 2040 and the resulting determination that no new school facilities would be required remain valid. The proposed project would not affect the number of students generated or the service standards of the school district. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered school facilities. iv. Parks? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered park facilities. The Certified El R concluded that impacts to parks would be less than significant because the General Plan 2040 would improve the citywide parkland ratio (to 2.77 acres per 1,000 residents) and would utilize existing park dedication and fee ordinances. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected population or housing units that generate service demand. The proposed project would not affect the number of residents or the park service standards of the City. Additionally, the proposed project establishes ODS that would require new multifamily and mixed -use projects to incorporate various forms of on -site private recreational open space (e.g., courtyards, common areas). The proposed project would minimize the demand placed on public parks by requiring high -quality, private recreational amenities within the new development projects. Specifically, the proposed project contains standards that are designed to encourage architectural diversity and ensure all buildings contribute to an active public realm while providing private outdoor amenities such as gardens, courtyards, and porches, where appropriate. The provision of these functional, on -site, private recreational spaces would lessen the demand on existing public neighborhoods and regional parks generated by residents, thereby protecting the service ratios and physical integrity of the public park system. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered park facilities. V. Other public facilities? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on other public facilities. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected population or housing units that generate service demand. The proposed project would not affect the number of residents or the service standards of the City. The proposed project would not influence the operational needs, staffing levels, or physical requirements of other public facilities, such as administrative or library facilities. The proposed project does not increase the projected growth, therefore, the demand for other public facilities remains consistent with the assumptions in the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial adverse physical impacts associated with the provision of, or need for, new or physically altered public facilities. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 65 Page 269 of 328 (b) Would the proposed project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the substantial physical deterioration of recreational facilities. The Certified EIR determined that impacts related to substantial physical deterioration of recreational facilities would be significant and unavoidable, as the potential increase in population anticipated by the General Plan 2040 could place additional physical demands on existing parks. The potential increase in population has the potential to increase the use of vital park elements such as vegetation, built structures, paths, and sport facilities, resulting in increased wear and tear and a shortened lifespan. However, the implementation of the proposed project would not accelerate the physical deterioration of recreational facilities because the proposed project would not increase the City's population or growth rate beyond the levels analyzed in the Certified EIR (please see Section 3.10, Land Use and Housing). Moreover, the proposed project establishes ODS that would require new multifamily and mixed -use projects to incorporate various forms of high -quality, on -site, private outdoor amenities such as gardens, courtyards, and porches, where appropriate. This would ensure that new residents have immediate and attractive recreational options within their own development. By providing functional, well -designed private recreational space, the proposed project would disperse and absorb recreational usage that might otherwise fall onto public parks, supporting the longevity of existing neighborhood and regional parks and decreasing the severity of the significant impact identified in the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to the substantial physical deterioration of recreational facilities. (c) Does the proposed project include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the construction or expansion of recreational facilities. The Certified EIR found that new park developments required to serve the General Plan's anticipated growth could result in adverse physical effects, including conversion of habitat, water pollution during construction, increased noise levels, and an increase in impermeable surfaces. However, the Certified El R determined that with compliance with existing regulations and General Plan 2040 policies, the overall impact would be less than significant. The proposed project does not include or require the construction or expansion of any public recreational facilities (e.g., new public parks, public sports fields). The proposed project is a set of ODS that would include the incorporation of private recreational facilities (e.g., internal courtyards, communal plazas, and gardens) as features of new multifamily residential and mixed -use developments. Consistent with the Certified EIR, impacts associated with new recreation facilities would be less than significant with implementation of existing regulations and proposed General Plan policies. Additionally, new developments and associated private recreational spaces would be subject to project -specific CEQA requirements for environmental assessment. Therefore, the proposed project would not Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 66 Page 270 of 328 result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to construction or expansion of recreational facilities. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to public facilities and recreation. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to public facilities or recreation for the proposed project that were not previously analyzed in the Certified EIR. The Certified EIR determined that the General Plan 2040 would not result in cumulatively considerable adverse impacts to fire stations, police stations, schools, or other public facilities. However, the Certified EIR determined that the project population growth may result in a cumulatively considerable impact on parkland due to the overuse and degradation of existing park facilities, as the General Plan 2040 would not provide sufficient park access to all residents. Elements of the proposed General Plan 2040 were designed to minimize potentially cumulatively considerable environmental impacts of new development, including developing sustainable park and recreational facility design and planning standards. The proposed project is an architectural and functional design overlay that regulates the visual quality and on -site amenities of new development. As stated in Section 3.10, Land Use and Housing, the proposed project does not propose new development, increase development capacity, change land use designations, extend utility infrastructure or roads, nor include provisions for new businesses. As such, the proposed project would not increase the projected population or housing units that generate service demand. The proposed project would also not affect the number of residents or the service standards of the City, and it does not introduce any new demand for public services that was not already accounted for in the Certified EIR. The proposed project is an implementing tool that regulates the design of development already assessed in the Certified EIR. Further, the proposed project contains provisions that functionally reduce stress on public park resources due to the provision of private on -site amenities such as courtyards, plazas, and gardens. The proposed project thereby would reduce the overuse and degradation of existing public park facilities that was found in the Certified EIR. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts to fire stations, police stations, schools, parks, or other public facilities. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 67 Page 271 of 328 3.13 TRANSPORTATION This section evaluates the effects on transportation from the proposed project. This Addendum relies on and incorporates by reference a project setting and regulatory setting as described in Section 3.12, Transportation, of the Certified EIR. Potential impacts to transportation from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that impacts related to conflict or inconsistency with State CEQA Guidelines Section 15064.3(b) would be significant and unavoidable, with no feasible mitigation available to reduce these impacts to a less than significant level. The Certified EIR determined that impacts related to conflicts with applicable plans, substantial increases in hazards due to a geometric design feature, and inadequate emergency access would be less than significant. Consistent with the Certified EIR, transportation impacts from the proposed project were evaluated with regard to the General Plan 2040. 3.13.1 Setting A review of available records and literature determined that no new information of substantial importance was identified that was not known at the time of the certification of the Certified EIR. Thus, the project setting for transportation is consistent with the setting considered in the Certified EIR. 3.13.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to transportation was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines: (a) Would the proposed project conflict with a program, plan, ordinance or policy addressing the circulation system, including transit, roadway, bicycle and pedestrian facilities? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a conflict with a program, plan, ordinance, or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities. The proposed project would set new minimum design standards for future multifamily and mixed -use development throughout the City (see Section 2.2). These new minimum design standards would work in tandem with City regulations related to transportation and traffic, including Title 22 of the City's Development Code and General Plan 2040. Application of the proposed project to future multifamily and mixed -use development would be subject to project -specific development review requirements and compliance with existing regulations that focus on improving transportation and traffic. As the proposed project would not result in additional development beyond what was considered in the Certified EIR, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to any conflicts with a program, plan, ordinance or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 68 Page 272 of 328 (b) Would the proposed project conflict or be inconsistent with CEQA Guidelines § 15064.3, subdivision (b)? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to a conflict or inconsistency with State CEQA Guidelines Section 15064.3(b). The Certified EIR found that the implementation of the General Plan 2040 would increase both resident and employee VMT per capita on a citywide basis, even with the City's goals and policies to reduce potential impacts. State CEQA Guidelines Section 15064.3(b) denotes criteria for the analysis of transportation impacts; specifically, the change in VMT as a result of a project. According to State CEQA Guidelines Section 15064.3(a), VMT refers to "the amount and distance of automobile travel attributable to a project."" The proposed project is a design overlay that works within the regulatory framework and cumulative growth assumptions of the Certified EIR and would not add more vehicles compared to the Certified EIR; thus, there would be no increase in VMT as a result of the proposed project. According to Principle 4, the ODS aim to "support multi -modal development and mobility." Multi -modal development and mobility rely on expanding travel mode choice, which "will help to promote business, provide access to opportunity, and improve the quality of life across our state."'$ Expanding travel mode choices helps to decrease overall VMT because of the availability of greater travel options (e.g., bicycles, ride -hailing services). Section 5.12 of the ODS (Appendix A) provides short-term guidelines regarding bicycle parking standards for site and open space standards. Therefore, there would be no conflict with State CEQA Guidelines Section 15064.3(b). As mentioned in Section 3.13, the application of the proposed project to future multifamily housing and mixed -use development would be subject to development review requirements and compliance with existing regulations that focus on improving transportation and traffic. As there would be no increase in VMT from the application of the proposed project to future multifamily and mixed -use development, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts previously identified in the Certified EIR as it relates to CEQA Guideline Section 15064.3, Subdivision (b). (c) Would the proposed project substantially increase hazards due to a geometric design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment) ? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantial increase in hazards due to a geometric design feature or incompatible uses. The Certified EIR found that impacts regarding an increase in hazards due to a design feature or incompatible uses would be less than significant with adherence to General Plan 2040 policies. As discussed in Section 3.13, the proposed project would set new minimum design standards for future multifamily and mixed -use development throughout the City (see Section 2.2) and would work in tandem with City regulations related to transportation and traffic, including Title 22 of the City's Development Code and General Plan 2040. The application of the "California Association of Environmental Professionals. January 2025. 2025 California Environmental Quality Act (CEQA) Statute and Guidelines. https://www.califaep.org/docs/CEQA_Handbook_2025combined.pdf (accessed October 29, 2025). '$ State of California: Governor's Office of Land Use and Planning. 2025. CEQA: Transportation Impacts (SB 743). https:Hlci.ca.gov/ceqa/sb-743/ (accessed October 29, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 69 Page 273 of 328 proposed project to future multifamily housing and mixed -use development would be subject to development review requirements and compliance with existing regulations that focus on improving transportation and traffic. Specifically, Principle 8 of the ODS would "provide off-street parking in surface lots or garages at the rear of buildings so that parking does not dominate the built environment," thereby, reducing incompatible land uses in the City. In addition, Principle 2 of the ODS would "ensure that streets and spaces with high volumes of pedestrian traffic are comfortable ... and physically engaging at the ground level." Furthermore, no sharp curves or dangerous intersections would be included as part of the proposed project. As the proposed project would not result in additional development beyond what was considered in the Certified EIR, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to an increase in hazards due to a design feature or incompatible uses. (d) Would the project result in inadequate emergency access? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to inadequate emergency access. The Certified EIR found that impacts would be less than significant, as inadequate emergency access would not occur with adherence to General Plan 2040 policies. The proposed project would not add more vehicles compared to the Certified EIR. As such, the proposed project would not contribute to congestion and, therefore, not inhibit emergency access to future multifamily housing and mixed -use developments in the case of an emergency. In addition, the proposed project would not result in greater multifamily housing and mixed -use density and would not result in a greater need for emergency response, compared to the Certified EIR. While the proposed project would not adversely affect the emergency access system, all future multifamily housing and mixed -use development subject to the proposed project would continue to be subject to development review requirements and compliance with existing regulations that focus on improving transportation and traffic, including Title 22 of the City's Development Code and the General Plan 2040. The proposed project would not result in additional development beyond what was considered in the Certified EIR. As there would be no additional development, there would be no additional vehicles added as a result of the proposed project. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to inadequate emergency access. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to transportation. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to transportation for the proposed project that were not previously analyzed in the Certified EIR. The Certified EIR found that, as a result of the amount of development anticipated by the General Plan 2040, the travel demand and VMT was the cumulative condition for CEQA purposes. Under the General Plan 2040 cumulative scenario, VMT was expected to increase compared to existing conditions. Per CEQA Guidelines Section 15064.3, this constitutes a considerable contribution to the significant impact regarding Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 70 Page 274 of 328 VMT. However, the General Plan 2040 would result in a less than cumulatively considerable contribution towards conflicts with programs and plans that address the circulation system given that the proposed General Plan includes multiple policies that improve multi -modal mobility and would expand the existing bicycle and pedestrian facilities while accommodating vehicle traffic. Additionally, the proposed General Plan 2040 would have a less than cumulatively considerable impact on hazards and emergency access. The proposed project would not create new or substantially more adverse significant impacts related to the cumulative transportation impacts from those previously disclosed in the Certified EIR. The proposed project would not increase population, change land uses, or otherwise add more vehicles to the road; therefore, it would not increase VMT beyond levels previously analyzed in the Certified EIR. With respect to conflict with adopted policies, plans, ordinances, or programs; hazardous design features; and inadequate emergency access, the proposed project's impacts would be negligible. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to transportation. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 71 Page 275 of 328 3.14 TRIBAL CULTURAL RESOURCES This section evaluates the potential environmental effects on tribal cultural resources from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.4, Cultural, Historic, and Tribal Cultural Resources, of the Certified EIR. Potential impacts to tribal cultural resources from the proposed project are discussed relative to the conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant impacts to tribal cultural resources. 3.14.1 Setting The environmental setting for tribal cultural resources is consistent with what was described in the Certified EIR. As discussed in the Certified EIR, no tribal cultural resources have yet been recorded within the City. The regulatory setting applicable to tribal cultural resources presented in the Certified EIR, including the California Register of Historic Resources, AB 52, SB 18, and all applicable state and local regulations are the same and apply to the proposed project. 3.14.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts on tribal cultural resources was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. (a) Would the proposed project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code § 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is: i. Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in Public Resources Code section 5020.1(k), or ii. A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Public Resources Code § 5024.1. In applying the criteria set forth in subdivision (c) of Public Resource Code § 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe. The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to tribal cultural resources. The Certified EIR determined that impacts would be less than significant. As discussed in the Certified EIR, no tribal cultural resources have been recorded within the City. However, it is possible that future development could result in discovery of yet unrecorded tribal cultural resources. Implementation of state and local regulatory guidelines pertaining to tribal cultural resources, such as AB 52 that would require Native American consultation to identify and mitigate potential adverse effects to tribal cultural resources, would reduce potential adverse effects to less than significant. The proposed project Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 72 Page 276 of 328 is intended to regulate visual design and would have no effect on tribal cultural resources beyond those effects previously evaluated in the Certified EIR. Further, consistent with the Certified EIR, regulatory compliance with state and local regulatory guidelines would ensure that impacts would be less than significant for the proposed project. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to tribal cultural resources. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to tribal cultural resources. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to land use or housing for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified EIR, cumulative impacts to tribal cultural resources would not be cumulatively considerable with implementation of AB 52 involving consultation with Native American tribes to establish development processes that avoid or mitigate adverse impacts to tribal cultural resources. Therefore, the proposed project's contribution to cumulative impacts of tribal cultural resources is not cumulatively considerable. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to tribal cultural resources. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 73 Page 277 of 328 3.15 UTILITIES AND SERVICE SYSTEMS This section evaluates the effects on utilities and service systems from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.13, Utilities and Service Systems, of the Certified EIR. Consistent with the Certified EIR, utilities and service systems for the proposed project were evaluated with regard to the Los Angeles County General Plan, Los Angeles County Code, the GLACR IRWM, the Walnut Valley Water District UMWP and the Diamond Bar City Code. 3.15.1 Setting The physical and regulatory environmental setting for utilities and service systems is the same as described in the Certified EIR. The proposed project does not alter the physical or regulatory conditions described in the Certified EIR. 3.15.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to utilities and service systems was evaluated in relation to the following questions as stated in Appendix G of the State CEQA Guidelines. (a) Would the proposed project require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the relocation or construction of new or expanded utilities and service systems. Implementation of the ODS would not increase demand for utilities or service systems because it would not increase the number of residences or commercial development in the City. All future multifamily and mixed -use development that would be subject to the ODS are already anticipated under the General Plan 2040 and analyzed in the Certified EIR. As such, the proposed project would not require the expansion of utilities or service systems as it would not increase overall service demand beyond the General Plan's projections. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the construction of new or expanded utilities and service systems. (b) Would the proposed project have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry and multiple dry years? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to sufficient water supplies. The Certified EIR determined that the Walnut Valley Water District, which serves the Planning Area, has sufficient water supply (per its Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 74 Page 278 of 328 UWMP) to meet the projected demand from the full buildout of the General Plan 2040 during normal, dry, and multiple dry years, resulting in a less than significant impact. As the proposed project would not increase the number of housing units or commercial development beyond that which was analyzed in the Certified EIR, the proposed project would not add any new, unanalyzed demand on water supplies. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to water supplies. (c) Would the proposed project result in a determination by the wastewater treatment provider, which serves or may serve the project that it has adequate capacity to serve the project's projected demand in addition to the provider's existing commitments? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to wastewater treatment capacity. The Certified EIR concluded that the wastewater treatment provider, the Los Angeles County Sanitation Districts, has adequate capacity to serve the projected increase in demand resulting from the full buildout of the General Plan 2040. The proposed project would not generate new wastewater flow beyond the amount projected in the General Plan 2040 and Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to wastewater treatment capacity. (d) Would the proposed project generate solid waste in excess of state or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the generation of solid waste. The Certified EIR determined that the projected increase in solid waste generation from the General Plan 2040 buildout would not exceed local infrastructure capacity or impair reduction goals, due to mandatory compliance with state laws (e.g., AB 341, AB 1826, SB 1383) that require source reduction and recycling. As the proposed project would not increase the number of housing units or commercial development beyond the that which was analyzed in the Certified EIR, the proposed project would not generate any additional solid waste. Therefore, the proposed project would not result in a new significant impactor a substantial increase in the severity of previously identified significant impacts in relation to the generation of solid waste. (e) Would the proposed project comply with federal, state, and local management and reduction statutes and regulations related to solid waste? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to compliance with solid waste statutes and regulations. The proposed project does not contain any provision that contradicts or overrides mandatory federal, state, or local statutes governing solid waste management (such as SB 1383). Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to compliance with solid waste statutes and regulations. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 75 Page 279 of 328 Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to utilities and service systems. No further mitigation measures are required. Cumulative Impact Analysis The implementation of the proposed project would not result in or contribute to a cumulative utilities and service systems impact. This conclusion is based on the function of the ODS as a design overlay that works within the regulatory framework and cumulative growth assumptions of the Certified EIR. The Certified EIR analyzed the cumulative impacts of full buildout under the General Plan 2040, which includes the maximum demand for utilities and service systems in the City. The Certified EIR concluded that the cumulative impacts to utilities and service systems would not be cumulatively considerable. Therefore, the proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts in relation to utilities and service systems. Diamond Bar Objective Design Standards February 2026 Page 76 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 280 of 328 3.16 WILDFIRE This section discusses the effects on wildfire from the proposed project. This Addendum relies on and incorporates by reference the project setting and regulatory setting as described in Section 3.7, Hazards, Hazardous Materials, and Wildfire, of the Certified EIR. Potential impacts to wildfire from the proposed project are discussed relative to conclusions in the Certified EIR. The Certified EIR determined that the implementation of the General Plan 2040 would result in less than significant wildfire impacts, with no mitigation measures required. Consistent with the Certified EIR, wildfire for the proposed project was evaluated with regard to the General Plan 2040 and the California Department of Forestry and Fire Protection (Cal FIRE) Fire Hazard Severity Zone (FHSZ) maps. 3.16.1 Setting As previously described, the project setting for wildfire is the same as that considered in the Certified EIR. A review of available records and literature determined that new wildfire information has become available since the certification of the EIR, including: (1) a March 2025 update to Cal FIRE's FHSZ maps based on revised wildfire modeling and climate data, and updated risk assessments; and (2) development standards ingrained under Title 32 — the County of Los Angeles Fire Code, which incorporates the California Fire Code. The Certified EIR found that FHSZs are present in several locations throughout the City but are confined exclusively to those areas that the General Plan 2040 designates for open and rural residential land uses. However, based on review of the March 2025 CAL FIRE FHSZ maps, the study area contains lands classified as Very High FHSZ (VHFHSZ) and a Local Responsibility Area (LRA).19 3.16.2 Impact Analysis Project Impact Analysis The potential for the proposed project to result in a new significant impact or a substantial increase in the severity of previously identified significant impacts to wildfire was evaluated in relation to the following questions as stated in Appendix G of the 2025 CEQA Guidelines. If located in or near state responsibility areas (SRAs) or lands classified as VHFHSZs, would the proposed project: (a) Substantially impair an adopted emergency response plan or emergency evacuation plan? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to substantially impairing an adopted emergency response plan or emergency evacuation plan. The Certified EIR found that the General Plan 2040 would result in less than significant impacts in relation to applicable adopted emergency response plans or emergency evacuation plans through compliance with existing local programs, regulations, and "California Department of Forestry and Fire Protection (Cal FIRE) Office of the State Marshall. 2025. Find Your Fire Hazard Severity Zone (FHSZ). https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and- mitigation/fire-hazard-severity-zones (accessed November 5, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 77 Page 281 of 328 General Plan 2040 policies. The City is located within lands classified as VH FHSZ and an LRA.20 The future multifamily and mixed -use developments that would be subject to the proposed project would also be subject to project -specific development review requirements and compliance with existing wildfire -based regulations, including Title 32 of the County Fire Code, Cal FIRE's FHSZ maps, and the General Plan 2040 (e.g., policies PS-P-16 and PS-P-23 to ensure minimal development intensification within or around VHFHSZs). Future multifamily and mixed -use development would also need to assess, as part of development review requirements, consistency with the County's disaster routes21 and the Diamond Bar Local Hazard Mitigation Plan.22 The proposed project does not introduce any elements or changes to primary circulation that would physically interfere with designated emergency evacuation routes. As discussed in Section 3.13, Transportation, the proposed project would not result in greater multifamily housing and mixed -use density and would not result in a greater need for emergency response nor increase congestion, compared to the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to substantial impairment of an adopted emergency response plan or emergency evacuation plan. (b) Due to slope, prevailing winds, and other factors, exacerbate wildfire risks, and thereby expose project occupants to pollutant concentrations from a wildfire or the uncontrolled spread of a wildfire? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to exacerbating wildfire risks and exposing occupants to wildfire hazards. The Certified EIR found that the General Plan 2040 would result in less than significant impacts, as intensive development is not expected to occur in or around SRAs or VHFSZs, and compliance with existing local programs, regulations, and General Plan 2040 policies would ensure that impacts would be less than significant. The proposed project would set new minimum design standards for future multifamily and mixed -use development throughout the City (see Section 2, Project Description) and would not change the land uses established in the General Plan 2040 and considered in the Certified EIR. Differing from the Certified EIR, multifamily and mixed -use development may occur in or around SRAs or VHFSZs. However, consistent with the Certified EIR, the future multifamily and mixed -use development subject to the proposed project would continue to be subject to project -specific development review requirements and compliance with existing regulations, which would reduce impacts associated with wildfire risks from slope, prevailing winds, and other factors to be below the level of significance. Accordingly, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to slope, prevailing winds, and other factors, exacerbating wildfire risk. 21 California Department of Forestry and Fire Protection (Cal FIRE) Office of the State Marshall. 2025. Find Your Fire Hazard Severity Zone (FHSZ). https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and- mitigation/fire-hazard-severity-zones (accessed November 5, 2025). 21 County of Los Angeles. N.d. Disaster Route Maps (by City): Area D — Diamond Bar. https:Hdpw.lacounty.gov/dsg/DisasterRoutes/city.cfm (accessed November 5, 2025) 22 City of Diamond Bar. 2022. 2022 Hazard Mitigation Plan. https://www.diamondbarca.gov/Docu mentCenter/View/10286/Diamond-Bar-Local-Hazard-Mitigation-Plan- 2022?bidld= (accessed November 20, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 78 Page 282 of 328 (c) Require the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency water sources, power lines or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to the installation or maintenance of infrastructure that may exacerbate fire risk. The Certified EIR found that the General Plan 2040 would result in less than significant impacts, as infrastructure development of the General Plan 2040 would be located away from SRAs and VHFSZs, and General Plan 2040 policies serve to mitigate wildfire risk. The City contains lands classified as VHFHSZs and an LRA, and the proposed project has the potential to apply to development in these areas. However, consistent with the Certified EIR, "should development occur in or around State Responsibility Areas or VHFSZs, components of the [General Plan 2040] serve to mitigate wildfire risk, and would thus keep the construction of additional infrastructure needed to combat fire to a minimum."23 Specifically, the Certified EIR found that the following General Plan 2040 policies would address risks associated with wildfire exposure: Policies PS-G-3, PS-P-14, PS-P-16, PS-P-17, PS-P-18, PS-P-19, PS-P-20, PS-P-22, PS-P-23, PS-P-32, PS-P-33, LU-G-2, LU-G-4, LU-P-2, LU-G-28, and LU-P-56.24 The future multifamily and mixed -use development subject to the proposed project would also be subject to project -specific development review requirements and compliance with existing regulations. Furthermore, the proposed project is a set of design standards and would not include new roads, fuel breaks, emergency water sources, power lines, or other utilities compared to the Certified EIR. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to requiring the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency water sources, power lines or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment. (d) Expose people or structures to significant risks, including downslope or downstream flooding or landslides, as a result of runoff, post -fire slope instability, or drainage changes? The proposed project would not exceed General Plan 2040 assumptions, and it would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts in relation to exposing people or structures to significant risks as a result of runoff, postfire slope instability, or drainage changes. The Certified EIR determined that the General Plan 2040 would result in less than significant impacts through compliance with existing local programs, regulations, and General Plan 2040 policies. The future multifamily and mixed - use development that would be subject to the proposed project would continue to be subject to project -specific development review requirements and compliance with existing regulations. As discussed in Section 3.9, Hydrology and Water Quality, LID development practices as regulated by local ordinances and MS4 Permit (Order No. R4-2012-0175) would help manage the runoff rate and volume to prevent new flooding, regardless of the architectural style required by the proposed project. All future development would be subject to the provisions of CEQA inclusive of 23 City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft Environmental Impact Report. P. 3.7-5. https://ceqanet.opr.ca.gov/2018051066/2 24 City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/DocumentCenter/View/7072/Diamond-Bar-General-Plan-2040?bidId= (accessed November 5, 2025). Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 79 Page 283 of 328 additional survey, design, and engineering and would be required to abide by city, state, and federal regulations. As discussed in Section 3.6, Geology, Soils, and Seismicity, future development subject to the proposed project would not expose people or structures to landslides since these future developments would not be located within steep hillsides in the City, which are areas that can produce landslides. Additionally, comprehensive geotechnical reporting and compliance with the design provisions of the CBC and General Plan 2040 policies for hillside development would be required for all future development subject to the proposed project. As such, consistent with the Certified EIR, future development subject to the proposed project would comply with existing local programs, regulations, and General Plan 2040 policies such that people or structures would not be exposed to significant risks. Therefore, the proposed project would not result in a new significant impact or a substantial increase in the severity of previously identified significant impacts related to exposing people or structures to significant risks as a result of runoff, post -fire slope instability, or drainage changes. Mitigation Measures As with the Certified EIR, no mitigation measures have been identified related to wildfire. No further mitigation measures are required. Cumulative Impact Analysis There are no new circumstances involving new impacts to wildfire for the proposed project that were not previously analyzed in the Certified EIR. As evaluated in the Certified EIR, the General Plan 2040 would result in a less than cumulatively considerable impact on the implementation of emergency response plans, fire risk, and associated effects on soil and water movement due to compliance with existing local programs, regulations, and General Plan 2040 policies. As discussed, the proposed project would not result in additional development that was not considered in the Certified EIR. The proposed project would not change the conclusions stated in the Certified EIR. Consistent with the Certified EIR, implementation of the proposed project would not result in a cumulatively considerable impact on wildfire, as all development would continue to comply with existing local programs, regulations, and General Plan 2040 policies that reduce fire risk. The proposed project would not result in a new significant cumulative impact or a substantial increase in the severity of previously identified significant cumulative impacts related to wildfire. Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 80 Page 284 of 328 4.0. LIST OF PREPARERS The following individuals contributed to the preparation of this document. 4.1 LEAD AGENCY City of Diamond Bar 21810 Copley Drive Diamond Bar, CA 91765 Contributor Title Area of Responsibility Greg Gubman Community Development Director Document Review Grace S. Lee Planning Manager Document Review Mavuko Nakaiima Senior Planner Document Review Ricia Hager Director — Woodruff & Smart Document Review Dan Cruz Associate — Woodruff & Smart Document Review 4.2 CONSULTANT Sapphos Environmental, Inc. 430 North Halstead St. Pasadena, CA 91107 Contributor Title Area of Responsibility Marie C. Campbell President Aimee Frappied Environmental Compliance Director Paulette Franco Environmental Compliance Specialist Rory Baker Environmental Compliance Coordinator Andy Dunlap Sustainability Coordinator Candace Rojas QSP/QSD Specialist Diana Dyste Cultural Resources Manager Jonathan Cain Sustainability Director Laura Razo CEQA Team Supervisor Matthew Adams Senior Technical Editor Morgan Thomas Cultural Resources Coordinator Stefanie Paz GIS Team Lead Principal -in -Charge EIR review / EIR author / Quality control EIR review / Quality control Project Manager / EIR author / Quality Control EIR author EIR author EIR review EIR review Quality control Document production EIR author GIS analysis Diamond Bar Objective Design Standards Addendum No. 2 to the EIR February 2026 Sapphos Environmental, Inc. Page 81 Page 285 of 328 5.0. REFERENCES California Air Resources Board. 2022. Area Designations Maps / State Ambient Air Quality Standards. http://www.arb.ca.gov/desig/adm/adm.htm (accessed October 24, 2025). California Air Resources Board. December 2022. 2022 Scoping Plan for Achieving Carbon Neutrality. https://ww2.arb.ca.gov/sites/default/files/2023-04/2022-sp.pdf (accessed November 3, 2025). California Association of Environmental Professionals. January 2025. 2025 California Environmental Quality Act (CEQA) Statute and Guidelines. https://www.califaep.org/docs/CEQA—Handbook_2025combined.pdf (accessed October 29, 2025). California Department of Forestry and Fire Protection (Cal FIRE) Office of the State Marshall. 2025. Find Your Fire Hazard Severity Zone (FHSZ). https://osfm.fire.ca.gov/what-we- do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity-zones (accessed November 5, 2025). California Department of Water Resources. 2003. California's Groundwater. Bulletin 118 — Update 2003. City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft Environmental Impact Report. https://ceqanet.opr.ca.gov/2018051066/2 City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan-2040 City of Diamond Bar. 2019. Diamond Bar General Plan 2040: Chapter 2. Land Use and Economic Development. https://www.diamondbarca.gov/DocumentCenterNiew/7089/2- Land-Use-Econ-Devr?bidld= (accessed September 29, 2025). City of Diamond Bar. 2022. 2022 Hazard Mitigation Plan. https://www.diamondbarca.gov/DocumentCenterNiew/l 0286/Diamond-Bar-Local- Hazard-Mitigation-Plan-2022?bidld= (accessed November 20, 2025). City of Diamond Bar. 2022. Diamond Bar General Plan 2040 Housing Element Update 2021- 2029. City of Diamond Bar. November 2019. Mitigation Monitoring & Reporting Program for the City Of Diamond Bar General Plan 2040 And Climate Action Plan 2040 Environmental Impact Report. SCH No. 2018051066. County of Los Angeles. N.d. Disaster Route Maps (by City): Area D — Diamond Bar. https://dpw.lacounty.gov/dsg/DisasterRoutes/city.cfm (accessed November 5, 2025) Federal Emergency Management Agency. 2008. National Flood Insurance Program Flood Insurance Rate Map for Los Angeles County and Incorporated Areas. Diamond Bar Objective Design Standards February 2026 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 82 Page 286 of 328 Southern California Association of Governments. 2024. Connect SoCal: A Plan for Navigating to a Brighter Future. https://scag.ca.gov/sites/default/files/2024-05/23-2987-connect-socal- 2024-final-complete-040424.pdf (accessed October 30, 2025). State of California: Governor's Office of Land Use and Planning. 2025. CEQA: Transportation Impacts (SB 743). https://Ici.ca.gov/ceqa/sb-743/ (accessed October 29, 2025). U.S. Environmental Protection Agency. 2023. Nonattainment Areas for Criteria Pollutants. https://www.epa.gov/green-book (accessed October 24, 2025). Diamond Bar Objective Design Standards February 2026 Addendum No. 2 to the EIR Sapphos Environmental, Inc. Page 83 Page 287 of 328 APPENDIX A Diamond Bar Objective Design Standards for Multifamily and Mixed -Use Development REMOVED (SEE EXHIBIT TO DRAFT ORDINANCE FOR ODS) Page 288 of 328 APPENDIX B Mitigation Monitoring and Reporting Program Page 289 of 328 Mitigation Monitoring & Reporting Program for the CITY OF DIAMOND BAR GENERAL PLAN 2040 AND CLIMATE ACTION PLAN 2040 ENVIRONMENTAL IMPACT REPORT SC H No. 2018051066 City of D iam and Bar November 2019 Page 290 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Ran 2040 This page intentionally loft blank. Page 291 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Ran 2040 1 Purpose State of California Public Resources Code Section 21081.6(a)(1) requires a lead or responsible agency that approves or carries out a project where an Environmental Impact Report (EI R) has identified significant environmental effects to adopt a reporting or monitoring program for the changes madeto the projector conditionsof project approval, adopted in order to mitigateor avoid significant effectson theenvironment. The City of Diamond Bar (the"City") isthelead agencyfor the EIR prepared for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 (SCH No. 2018051066), hereafter referred to as "Proposed Project," and therefore isresponsi blefor theadoption and implementation of therequired mitigation monitoring and reporting program. An EIRhasbeen prepared fortheProposed Project that addresses potenti al environmental impacts and, where appropriate, recommends measures to mitigate these impacts. The Mitigation Monitoring and Reporting Program (MMRP) has been prepared in conformance with Public Resources Code Section 21081.6(a)(1). It istheintent of thisprogram to: 1. Verify satisfaction of therequired mitigation measuresof the EI R; 2. Provide a methodology to document implementation of therequired mitigation; 3. Providea record of themonitoring program; 4. Identify monitoring responsibility; 5. Establish administrative proceduresfor theclearanceof mitigation measures; 6. Establish thefrequency and duration of monitoring; and 7. Utilizeexisting re/ieN processes wherever feasible. The MMRP describes the procedures that will be used to implement the mitigation measures adopted in connection with the approval of the Proposed Project and the methods of monitoring such actions. A monitoring program is necessary only for impactswhich would besignificant if not mitigated. If, during the course of project implementation, anyofthemitigation measures identified cannot besuccessfully implemented, the City shall immediately inform any affected responsibleagencies. TheCity, in conjunction with any affected responsibleagencies, will then determineif modification to theproject isrequired, and/or whether alternative mitigation isappropriate. The following consists of a monitori ng program table noting the respond ble entity for mitigation monitoring, thetiming, and alist of all project -related mitigation measures. Page 292 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Ran 2040 This page intentionally loft blank. Page 293 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 2 Mitigation Monitoring and Reporting Plan Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Air Quality Construction associated MM-AQ-1 Construction Features. Include in project Prior to City of with implementation of Future development projects conditions of issuance of Diamond Bar the Proposed Project implemented under the General Plan approval. construction Community would create new will be required to demonstrate permit. Development sources of VOC and consistency with SCAQMD Department NOx emissions that construction emission thresholds. exceeds SCAQMD's Where emissions from individual project -level thresholds projects exceed 9CAQMD thresholds, and contribute to the the following measures shall be nonattainment incorporated as necessary to minimize designation of the South impacts. These measures do not exclude Coast Air Basin for Os. the use of other, equally effective mitigation measures. • Require all off -road diesel equipment greater than 50 horsepower (hp) used for this Project to meet current UEEPA standards, which are currently Tier 4 final off -road emission standards or equivalent. Such equipment shall be outfitted with Best Available Control Technology (BACT) devices including a California Air Resources 3 Page 294 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Board certified Level 3 Diesel Particulate Filter (DPF) or equivalent. This DPFwill reduce diesel particulate matter and NOX emissions during construction activities. • Require a minimum of 50 percent of construction debris be diverted for recycling. • Require building materials to contain a minimum 10 percent recycled content. • Require materials such as paints, primers, sealants, coatings, and glues to have a low volatile organic compound concentration compared to conventional products. If low VOC materials are not available, architectural coating phasing should be extended sufficiently to reduce the daily emissions of VOCs. Operational sources MM-AQ-2: Future development. under the Proposed Under the Proposed Project, future Project would generate development would be required to emissions of VOC, N Ox, demonstrate consistency with CO, PM1o, and PM2.5 that SCAQMD's operational thresholds. For exceeds SCAQMD's projects where operational emissions project -level thresholds exceed regulatory thresholds the and contribute to the following measures may be used to nonattainment reduce impacts. Note the following designation of the SCAB measures are not all inclusive and for Os, PM2.5, and PM,o. developers have the option to add or substitute measures that are eaually or CI Method of Verification Timing of fbTonsibility for Verification Complete Verification Verification Date Initial Include in project Prior to Construction conditions of discretionary contractor; approval. project City of approval. Diamond Bar Community Development Department Page 295 of 328 Impact Biological Resources Construction associated with implementation of the Proposed Project could have an adverse effect on special -status plant species. Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure more appropriate for the scope of their project. • Develop a project specific TD M program for residents and/or employees that provides opportunities for carpool/vanpools. • Provide onsite solar/renewable energy in excess of regulatory requirements. • Require that owners/tenants of non- residential or multi -family residential developments use architectural coatings that are 10 grams per liter or lesswhen repainting/repairing properties. • Require dripless irrigation and irrigation sensor unitsthat prevent watering during rain storms. • Ensure all parking areas are wired capability of future EV charging and include EV charging stations that exceed regulatory requirements. Method of Verification Timing of Verification fb�qonsibility for Verification Complete Verification Date Initial Construction contractor; City of Diamond Bar Community • Prior to initiating disturbance Development activities, clearance surveys for Department special -status plant species shall be performed by a qualified biologist(s) MM-13I0-1A Preconstruction Sibmittal of Surveys for Special -Status Plants: preconstruction To mitigate impacts on special status surveys. plant species, the applicant shall implement the following measures: Prior to issuance of construction permit. 5 Page 296 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial within the boundaries of the future project disturbances. If any special - status plants are found on the Panning Area, a qualified biologist(s) with a CDFG Scientific Collection Permit shall prepare a plan to relocate these species to suitable habitats within surrounding public open space areas that would remain undisturbed. For those speciesthat cannot be physically transplanted, the biologist(s) shall collect seeds from the plants. (Note: Lilies generally can be transplanted in bulb -form.) • To the extent feasible the preconstruction surveys shall be completed when species are in bloom, typically between May and Jane and reference populations checked. Two species, the white rabbit -tobacco and San Bernardino aster, are perennial herbs that grow up to three feet in height and can be identified by their dried stalks and leaves following their blooming period. Construction associated MM-1131O-1113 Special -Status Plant Sibmittal of Special Prior to start Construction with implementation of Planting Plan: Prior to any ground Status Pant Panting of ground contractor; the Proposed Project disturbance for projects that have the Pan and appropriate disturbance City of could have an adverse potential to cause direct or indirect documentation. activities. Diamond Bar effect on special -status impacts on special -status plants, the Community plant species. project applicants shall prepare a '�pecial Development Status Pant Panting Pan for the species Department [ej Page 297 of 328 Impact Construction associated with implementation of the Proposed Project could have an adverse effect on special -status plant species. Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial to be transplanted. At a minimum, the plan shall include a description of the existing conditions of the project and receiver site(s), transplanting and/or seed collection/off-site seeding or installation methods, an adaptive two- year monitoring program, any other necessary monitoring procedures, plant spacing, and maintenance requirements. In the event that the City of Diamond Bar determines that agreed success criteria are not met, additional remediation may be required beyond the two-year maintenance/monitoring period to ensure mitigation requirements are met. The City shall also require proof that the plan preparer consulted with US Fish and Wildlife Service and California Department of Fish and Wildlife personnel or appropriate herbarium botanists in order to maximize transplanting success. (Note: Appropriate botanists include those at CDFW in Ontario, the Rancho Santa Ana Botanical Gardens in Claremont, UC Riverside, or Cal Fbly Pomona) MM-113I0-1C Listed Endangered Submittal of USFWS Prior to Construction and Threatened Plants: In addition and CDFW permits issuance of contractor; to MM BIO-1A and -1 B, the City shall and documentation. construction City of require the project applicant to provide permit. Diamond Bar proof of the USFsh and Wildlife Community Service and California Department of Development Fish and Wildlife permitting the take of Department 7 Page 298 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure listed endangered and threatened plants. The FESA does not address listed plants on private property. However, if a federal action is required for a project (funding, Clean Water Act compliance, etc.), a permit from the US:WSand CDFW to take a listed species is required. Implementation of the MM-1131O-1D Environmental Proposed Project could Awareness Program: In order to result in indirect impacts reduce indirect impacts on special -status on special -status plant plants, sensitive natural communities, species, sensitive natural preserved open space and wildlife communities, preserved corridors, the City shall implement the open space, and wildlife following measures: corridors. The City shall implement an Environmental Awareness Program on its web site intended to increase awareness to developers, residents and city workers of the sensitive plants, wildlife and associated habitats that occur in the preserved open space areas. The intention of the program shall be to inform developers, city workers, and residents and encourage active conservation efforts to help conserve the habitats in the preserved open space. The program shall address impacts associated with the introduction of invasive plant species as a result of new development. At a minimum, the 1.1 Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial Implementation of Ongoing. City of Environmental Diamond Bar Awareness Program. Community Development Department Page 299 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure Environmental Awareness Program shall include the following components: o Informational kiosks shall be added or modified at entrance points to hiking and equestrian trails to inform city workers, residents and trail users on the sensitive flora and fauna that rely on the habitats found within the preserved open space. The intent of these kiosks is to bring awareness to the sensitive plants, wildlife and associated habitats which occur in the area o The City shall provide future project applicants a brochure which includes a list of sensitive plant and tree species to avoid impactingaswell I as suggested plant palettes to be used in residential landscaping near natural areasto prevent the introduction of invasive plant species to the surrounding natural communities. Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial �] Page 300 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Construction associated MM-131O-1E Preconstruction Sibmittal of Prior to Construction with implementation of Surveys for Special -Status Wildlife: preconstruction issuance of contractor; the Proposed Project Within one (1) week prior to initiating surveys. construction City of could have an adverse disturbance activities, clearance surveys permit. Diamond Bar effect on special -status for special -status animal species shall be Community animal species. performed by a qualified biologist(s) Development within the boundaries of the future Department project disturbances. If any special - status animals are found on the site, a qualified biologist(s) flag the area for avoidance and discuss possible seasonal avoidance measures with the developer. If avoidance is not feasible, the Project Biologist, with a CDFG Scientific Collection Permit shall relocate these species to suitable habitats within surrounding open space areas that would remain undisturbed, unless the biologist determinesthat such relocation cannot reasonably be accomplished at which point CDFG will be consulted regarding whether relocation efforts should be terminated. Relocation methods (e.g., trap and release) and receiver sites shall be verified and approved by the CDFG prior to relocating any animals. Implementation of the MM-BIO-IF Listed Endangered Sibmittal of findings Prior to City of Proposed Project could or Threatened W ildlife: Prior to and documentation. discretionary Diamond Bar cause direct or indirect approval of individual projects that have project Community impacts on suitable the potential to cause direct or indirect approval. Development habitat for federally or impacts on suitable habitat for federally Department or state listed endangered or 10 Page 301 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure state listed endangered threatened species, the City shall or threatened species. require a habitat evaluation to be completed by a qualified biologist well versed in the requirements of the associated species to be completed. If no suitable habitat for listed species is identified within 300 feet of construction or maintenance activities, no further measures would be required in association with the project. If suitable habitat for the species is identified within 300 feet of such activities, prior to construction, the City shall require that a survey be completed by a qualified biologist for the species in accordance with protocols established by the US Fish and Wildlife Service. Table 3.3-5 provides a listing of endangered and threatened species by habitat type and potential for occurrence. In the event a state or federal listed species is determined to occupy the proposed Panning Area or its immediate surroundings, the CDFW and/or USFWSshall be consulted, as required by CES4 and/or FES4. In order to address and acknowledge the potential for listed species to occur within the Panning Area or be impacted by future development projects, this assessment acknowledges future actions by state and federal resource agencies in Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial 11 Page 302 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial addition to the analyses necessary and required under CEQA. Compensation is likely to include one or more of the following on- or off -site measures: dedication/preservation of suitable habitat for the species; habitat enhancement/creation; and provisions for long-term habitat management. Clearing and grading MM-131O-1G Nesting Bird SAbmittal of findings Prior to start City of activities associated with Surveys: All vegetation clearing for and documentation. of clearing Diamond Bar implementation of the construction and fuel modification shall and/or Community Proposed Project could occur outside of the breeding bird grading Development disturb nesting bird season, if feasible, to ensure that no activities. Department habitats. active nests would be disturbed unless clearing and/or grading activities cannot be avoided during that time period. If clearing and/or grading activities cannot be avoided during the breeding season, all suitable habitats shall be thoroughly surveyed for the presence of nesting birds by a qualified biologist prior to removal. 3aitable nesting habitat on the Ranning Area includes grassland, scrub, chaparral, and woodland communities. If any active nests are detected, the area shall be flagged, along with a 300-foot buffer for songbirds and a 500-foot buffer for raptorial birds (or as otherwise appropriate buffer as determined by the surveying biologist), and shall be avoided until the nesting cycle is complete or it 12 Page 303 of 328 Implementation of the Proposed Project could disturb active golden eagle nests. Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial is determined by the surveying biologist that the nest is no longer active. MM-131O-1H Protection of Eagle Sibmittal of findings Ongoing. City of Nests: No development or project and documentation. Diamond Bar activities shall be permitted within one- Community half mile of a determined active golden Development eagle nest unless the planned activities Department are sited in such away that the activity has minimal potential to cause abandonment of the nesting site, as determined by a qualified biologist. In addition, the eagle nest (if active) shall be monitored by a biologist who is highly familiar with the signs of eagle distress during the project development activities. The monitoring shall continue until the monitoring biologist is confident the nest will not be disturbed. The monitoring biologist shall have the authority to stop project activities as needed. (Note: Generally, information regarding the location of raptorial bird nests is kept highly confidential. As such it is recommended that representatives of CDPW, USFWSand/or the Chino Hills State Park be notified of any proposed projects in the 901 or Tres Hermanos portions of the Planning Area. In consultation with agency representatives, it can be determined if the Droiect is within one-half mile of the 13 Page 304 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Construction associated with implementation of the Proposed Project could disturb bat roosting habitat. Construction associated with implementation of the Proposed Project could disrupt bat roosting habitat. 14 Mitigation Measure eagle nest without the location being specifically identified.) MM-BIO-11 Use of Buffers Near Active Bat Roosts: During the November 1 to March 31 hibernation season, construction activities shall not be conducted within 100 feet of woodland habitat that provides suitable bat roosting habitat. Bat presence is difficult to detect using emergence surveys during this period due to decreased flight and foraging behavior. If a qualified biologist who is highly familiar with bat biology determines that woodland areas do not provide suitable hibernating conditions for bats and they are unlikely to be present in the area, work may commence as planned. MM BIO-1J Bat Maternity Roosting Season: Night-time evening emergence surveys and/or internal searches within large tree cavities shall be conducted by a qualified biologist who is highly familiar with bat biology during the maternity season (April 1 to August 31) to determine presence/absence of bat maternity roosts near wooded project boundaries. All active roosts identified during surveys shall be protected by a buffer to be determined by a qualified bat biologist. The buffer will be determined by the type of bat observed, Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial Sibmittal of findings During the Construction and documentation. November 1 contractor; through City of March 31 Diamond Bar hibernation Community season and Development shortly Department thereafter. Sibmittal of findings Duringthe Construction and documentation. April 1 contractor; through City of August 31 Diamond Bar maternity Community season. Development Department -%rveys valid 30 days from survey date. Page 305 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure topography, slope, aspect, surrounding vegetation, sensitivity of roost, type of potential disturbance, etc. Each exclusion zone would remain in place until the end of the maternity roosting season. If no active roosts are identified, then work may commence as planned. Survey results are valid for 30 days from the survey date. Should work commence later than 30 days from the survey date, surveys should be repeated. Construction associated MM BIO-1K Bat Roost with implementation of Replacement: All special -status bat the Proposed Project roosts that are destroyed by the project could disrupt bat must be documented and shall be roosting habitat. replaced at a 1:1 ratio on- or off -site with a roost suitable for the displaced species (e.g., bat houses for colonial roosters). The design of such replacement habitat shall be coordinated with CDFG. The new roost shall be in place prior to the time that the bats are expected to use the roost as determined by a qualified biologist who is highly familiar with bat biology, and shall be monitored periodically for five (5) years to ensure proper roosting habitat characteristics (e.g., suitable temperature and no leaks). The roost shall be modified as necessary to provide a suitable roosting environment for the target bat species. Method of Verification Timing of Verification Submittal of documentation. Prior to the time the bats are expected to use the roost as determined by a qualified biologist. Monitoring shall occur periodically over 5 years thereafter. fb�qonsibility for Verification Complete Verification Date Initial Construction contractor; City of Diamond Bar Community Development Department 15 Page 306 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Implementation of the MM BI0-2 Sensitive Natural Proposed Project could Communities: To mitigate impacts on result in adverse impacts sensitive shrubland and scrub natural to sensitive shrubland communities, project applicants shall and scrub natural implement the following mitigation communities. measures prior to any ground disturbance: • If avoidance cannot be reasonably accomplished, impacts on any shrubland, scrub or woodland alliance indicated as sensitive in Table 3.3-2 shall be mitigated through on - or off -site restoration/enhancement. For off -site restoration/enhancement, the applicant shall acquire mitigation land of similar habitat at a ratio of at least 1:1. On -site restoration/enhancement shall also be completed at a ratio of at least 1:1. • For projects that have the potential to result in direct or indirect impacts on sensitive natural communities, a habitat restoration plan shall be prepared prior to any ground disturbance. The Ran shall include adaptive management practices as specified by the Department of the Interior to achieve the specified ratio for restoration/enhancement. At a minimum, the Ran shall include a description of the existinq conditions 16 Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial S.ibmittal of Prior to start Construction documentation. of ground contractor; disturbance. City of Diamond Bar Community Development Department Page 307 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial of the receiver site(s), goals and timeline, installation methods, monitoring procedures, plant spacing, adaptive management strategies, and maintenance requirements to ensure the sensitive communities referred to above re- established successfully at the ratios set forth above. Implementation of the MM 113I0-3 .Jurisdictional -Submittal of Ongoing. Construction Proposed Project could Waters: To mitigate for impacts on documentation. contractor; result in adverse impacts jurisdictional waters, the applicant shall City of on jurisdictional waters. implement the following measures in Diamond Bar consultation with the regulating agencies Community (US4CE CDFW, and RWQCB, where Development applicable) over the course of the Department project: • The applicant shall provide on- and off -site replacement and/or restoration/enhancement of US4CF, RWQCB and CDFG jurisdictional waters and wetlands A a ratio no less than 1.5:1 and/or include the purchase of mitigation credits at an agency -approved off -site mitigation bank. • If replacement and/or restoration/enhancement would occur, a restoration plan shall be prepared that describes the location of restoration and provides for replanting and monitoring for a 17 Page 308 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure three-year period following construction. Implementation of the MM-13I0-4 Oak W oodlands: In Proposed Project could the event a future project would result result in a loss of oak in the loss of an oak woodland, the woodland. project shall be subject to the mitigation requirements set forth in the Los Angeles County Oak Woodland Conservation Management Plan Guide. If a future project cannot be redesigned to avoid impacts on oak woodland, then one of the following measures shall be implemented: • Acquire oak woodland habitat that is comparable to the habitat that was impacted at a ratio of 1:1. • Restore degraded oak woodlands o Off -site restoration should be prioritized over on -site restoration and where feasible, should be located nearby the impacted property, preferably within the same watershed or sub - drainage as deemed appropriate by a qualified biologist, or within the same planning area as the impacted property. Off -site restoration may include any of the following: acquiring off -site fee title for oak woodland habitat; 18 Method of Verification Timing of Verification BUbmittal of final Ongoing. report. Mitigation areas shall be placed in a conservation easement within 6 months of a project's completion. Project mitigation shall be monitored and reported on over a 7- year period. fb�ponsibility for Verification Complete Verification Date Initial Construction contractor; City of Diamond Bar Community Development Department Page 309 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure replacement planting; and/or restoring moderately or severely deg aded oak woodlands (more specifically, removing exotics and restoring appropriate native plant diversity). o On -site restoration of a ratio of at least 1:1 should be utilized when circumstances at the site allow for long-term sustainability of the replacement plantings, the potential to expand/connect to adjacent oak woodlands, and/or the improvement of degraded oak woodlands. If possible, on -site restoration areas should be located adjacent to preserved natural space. The project applicant shall replace/restore lost canopy area More specifically, the project applicant shall provide mitigation trees of the same Oak species. All replacement trees should be planted on native undisturbed soil and should be the same species of oak tQuercus sD.l as the Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial 19 Page 310 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact 20 Mitigation Measure removed tree with appropriate associated native vegetation in the understory. The location of the replacement tree should be in the vicinity of other oak trees of the same species. If replacement trees cannot be planted on native undisturbed soil or are not in the vicinity of the same species of oak (Quercus sp.) as the removed tree, the city may require implementation of additional measures as listed in MM- BIO-4 to ensure that trees thrive. Mitigation areas or land should be at a minimum of two (2) to one (1) canopy cover area for the amount removed. This is the expected canopy extent of mature trees. All mitigation areas or land should be placed in a conservation easement within six months of a project's completion. If a conservation easement is not possible, the land shall be protected in perpetuity by other means deemed acceptable by the City. Mitigation land may be designated public open space by the City if deemed appropriate per the description of Open dace found in Chapter 2: Land Use of the proposed General Ran. Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Page 311 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure Project mitigation shall be monitored and reported on over a seven-year period and shall incorporate an iterative process of annual monitoring and evaluation of progress and allow for adjustments to the program, as necessary, to achieve desired outcomes and meet success criteria Annual reports discussing the implementation, monitoring, and management of the mitigation project shall be submitted to the City and should contain the following components: description of the project impact and mitigation site; specific objectives(success criteria, evaluated based on approved survival rates and percent cover of planted native species; control of invasive plant and animal species within the mitigation site; monitoring and maintenance activities conducted since the previous report; and any contingency measures implemented since the previous report. Success criteria should be based on a reference site supporting the desired oak species and understory that the mitigation site is designed to achieve. Once the mitigation project has been completed, the applicant shall submit a final report to the City. The report shall discuss the implementation, monitoring and management of the mitigation Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial 21 Page 312 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure project over the seven-year period, and indicates whether the mitigation project has, in part, or in whole, been successful based on established success criteria. The project shall be extended if success criteria have not been met A the end of the seven-year period to the satisfaction of the City. Method of Verification Timing of Verification Implementation of the MM-1131O-5 Walnut Woodlands: -Submittal of final Proposed Project could In the event afuture project would report. result in a loss of oak result in the loss of a walnut woodland, woodland. then one of the following measures shall be implemented: • Acquire walnut woodland habitat that is comparable to the habitat that was impacted at a ratio of 1:1. • Restore degraded walnut woodlands o Off -site restoration should be prioritized over on -site restoration and where feasible, should be located nearby the impacted property, preferably within the some watershed or sub - drainage as deemed appropriate by a qualified biologist, or within the some planning area as the impacted property. Off -site restoration may include any of the following: acquiring off -site fee title for walnut woodland habitat; 22 Ongoing. Mitigation areas shall be placed in a conservation easement within 6 months of a project's completion. Project mitigation shall be monitored and reported on over a 7- year period. fb�qonsibility for Verification Complete Verification Date Initial Construction contractor; City of Diamond Bar Community Development Department Page 313 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure replacement planting; and/or restoring moderately or severely deg aded walnut woodlands (more specifically, removing exotics and restoring appropriate native plant diversity). o On -site restoration of a ratio of at least 1:1 should be utilized when circumstances at the site allow for long-term sustainability of the replacement plantings, the potential to expand/connect to adjacent walnut woodlands, and/or the improvement of degraded walnut woodlands. If possible, on -site restoration areas should be located adjacent to preserved natural space. The project applicant shall replace/restore lost canopy area More specifically, the project applicant shall provide mitigation trees of the same species comprising the walnut woodland, including the constituent or co -dominant oak species. All replacement trees Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial 23 Page 314 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact 24 Mitigation Measure should be planted on native undisturbed soil and should be the same species of walnut (,i.igjans sp.) and oak (Quercussp.) as the removed tree with appropriate associated native vegetation in the understory. The location of the replacement tree should be in the vicinity of other trees of the same species. If replacement trees cannot be planted on native undisturbed soil or are not in the vicinity of the same species as the removed tree, the city may require implementation of additional measures as listed in MM- BIO-5 to ensure that trees thrive. Mitigation areas or land should be at a minimum of two (2) to one (1) canopy cover area for the amount removed. This is the expected canopy extent of mature trees. All mitigation areas or land should be placed in a conservation easement within six months of a project's completion. If a conservation easement is not possible, the land shall be protected in perpetuity by other means deemed acceptable by the City. Mitigation land may be desicnated public Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Page 315 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure open space by the City if deemed appropriate per the description of Open Space found in Chapter 2: Land Use of the proposed General Ran. Project mitigation shall be monitored and reported on over a seven-year period and shall incorporate an iterative process of annual monitoring and evaluation of progress and allow for adjustments to the program, as necessary, to achieve desired outcomes and meet success criteria Annual reports discussing the implementation, monitoring, and management of the mitigation project shall be submitted to the City and should contain the following components: description of the project impact and mitigation site; specific objectives/success criteria, evaluated based on approved survival rates and percent cover of planted native species; control of invasive plant and animal species within the mitigation site; monitoring and maintenance activities conducted since the previous report; and any contingency measures implemented since the previous report. Success criteria should be based on a reference site supporting the desired walnut woodland species and understory that the mitigation site is designed to achieve. Method of Verification Timing of fb�qon§bility for Verification Complete Verification Verification Date Initial 25 Page 316 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Once the mitigation project has been completed, the applicant shall submit a final report to the City. The report shall discuss the implementation, monitoring and management of the mitigation project over the seven-year period, and indicates whether the mitigation project has, in part, or in whole, been successful based on established success criteria. The project shall be extended if success criteria have not been met at the end of the seven-year period to the satisfaction of the City. Implementation of the MM-113I0-6 W ildlife Movement Proposed Project could Corridor: In order to ensure the diminish the integrity of existing integrity of the Tonner Canyon the Tonner Canyon movement corridor, the following land movement corridor. use design criteria shall be adhered to when reviewing future projects: Corridor Features • The corridor should be as wide as possible. The corridor width may vary with habitat type or target species, but a rule of thumb is about a minimum of 1,000 feet wide (but larger if possible). • Maintain as much natural open space as possible next to any culverts and road undercrossings to encourage the use of these by wildlife. 26 Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial Include in project Prior to Construction conditions of discretionary contractor; approval. project City of approval. Diamond Bar Community Development Department Page 317 of 328 Impact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure • Maximize land uses adjacent to the corridor that reduce human impacts on the corridor. • Avoid development or other impacts to project into the corridor to form impedimentsto movement and increase harmful edge effects. • If development is to be permitted next to the corridor, put conservation easements on adjacent lots to prohibit structures nearest the corridor. • Develop strict maximum brightness restrictions for development adjacent to the corridor to prevent light trespass into the corridor. Lights must be directed downward and inward toward the development. Culvert Desim • Bridged undercrossings are preferable. • If a bridge is not possible, use a 12- foot by 12-foot box culvert or bigger for larger animals. • Install a small, one -foot diameter tube parallel to the large box culvert for small animals. The upstream end of the small tube should be afew inches higher than the bottom of the upstream end of the box culvert, so that it will stay dry and free of debris. Method of Verification Timing of fb�qonsibility for Verification Complete Verification Verification Date Initial 27 Page 318 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact M:3 Mitigation Measure • The culvert bottoms should be as close as possible to any canyon bottom and not be perched up afill slope. • Use natural substrate on the bottom of the culvert, such as dirt with pebbles. • On roads above the undercrossings and culverts, install speed bumps and wildlife crossing signs to slow the cars, and avoid street lighting to facilitate use of the crossing. • Plant and maintain vegetative cover (shrubs and low cover) near the entrance -exits of the culverts, without visually or physically blocking the entries. • Install appropriate fencing (at least six feet in height) to funnel animals towards the undercrossings and culverts. Vegetation Restoration • Require maintenance or restoration of native vegetation, and long-term management. • Develop an adequate endowment program for restoration and management of the corridor. • Rant native trees, shrubs, and other plants to provide food and cover, as well as nesting opportunities for birds. Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Page 319 of 328 irrpact Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Mitigation Measure Management and Enforcement • If housing is to be permitted adjacent to the corridor, require the homeowners associations or each homeowner to maintain -- on their own property -- a mowed, 30-foot to 60-foot buffer alongaflA or slightly sloped grade between the native vegetation in the corridor and each adjacent lot, for fire abatement. • Avoid fencing in the corridor that would bottleneck the corridor. • Unleashed domestic pets should not be allowed in the corridor. • Educate each landowner adjacent to the corridor about the regulations (lighting, mowing the buffer, no trespass, do not place pet food outside, etc.) and develop a pamphlet and convene a community meeting. In appropriate locations, install educational signs about the corridor and the species that could potentially use the corridor. Cultural, Historic, and Tribal Cultural Resources Implementation of the Proposed Project could cause adverse impacts on historical resources. MM-CULT-1 Prior to development of any project on a parcel containing at least one structure more than 45 years old and until such time a Citywide historic resource survey is completed, the project proponent shall retain a qualified architectural historian, defined Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Submittal of findings Prior to Construction and documentation. discretionary contractor; project City of approval. Diamond Bar Community Development Department 29 Page 320 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact 30 Mitigation Measure as meeting the Secretary of the Interior's Professional Qualification 3andardsfor architectural history, to conduct a preliminary assessment. If the property appears to be potentially eligible for a local, state and/or federal listing, afull historic resources assessment shall be required. A full historic resources assessment shall include: a records search at the South Central Coastal Information Center; a review of pertinent archives, databases, and sources; a pedestrian field survey; recordation of all identified historic resources on California Department of POrks and Recreation 523 forms; and preparation of a technical report documenting the methods and results of the assessment. All identified historic resources will be assessed for the project's potential to result in direct and/or indirect effects on those resources and any historic resource that may be affected shall be evaluated for its potential significance under national and state criteria prior to the City's approval of project plans and publication of subsequent CEQA documents. The qualified architectural historian shall provide recommendations regarding additional work, treatment, or mitigation for affected historical resources to be implemented prior to their demolition or alteration. Impacts Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial Page 321 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�pon§bility for Verification Complete Verification Verification Date Initial on historical resources shall be analyzed using CEQA thresholds to determine if a project would result in a substantial adverse change in the significance of a historical resource. If a potentially significant impact would occur, the City shall require appropriate mitigation to lessen the impact to the degree feasible. This mitigation measure shall not apply to minor projects that would otherwise qualify for an exemption under CEQA, such as, but not limited to, room additions, reroofs, and the removal of minor accessory structures and landscaping projects. Implementation of the MM-CULT-2 Prior to development Submittal of Prior to Construction Proposed Project could of a project that involves ground archaeological discretionary contractor; cause adverse impacts disturbance, the project proponent shall resources project City of on archaeological retain aqualified archaeologist, defined assessment. approval. Diamond Bar resources. as meeting the Secretary of the Community Interior's Professional Qualification Development Standards for archaeology, to conduct Department an archaeological resources assessment including: a records search at the South Central Coastal Information Center; a Sacred Lands File search at the Native American Heritage Commission; a pedestrian field survey; recordation of all identified archaeological resources on California Department of Parks and Recreation 523 forms; an assessment of the project area's archaeological sensitivity and the potential to encounter subsurface archaeological 31 Page 322 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial resources and human remains; subsurface investigation to define the horizontal and vertical extents of any identified archaeological resources; and preparation of a technical report documenting the methods and results of the study. All identified archaeological resources shall be assessed for the project's potential to result in direct and/or indirect effects on those resources and any archaeological resource that cannot be avoided shall be evaluated for its potential significance prior to the City's approval of project plans and publication of subsequent CEQA documents. The qualified archaeologist shall provide recommendations regarding protection of avoided resources and/or recommendations for additional work, treatment, or mitigation of significant resources that will be affected by the project. This mitigation measure shall not apply to minor projects that would otherwise qualify for an exemption under CEQA, such as, but not limited to, the construction of a single-family residences, excavations for swimming pools, and landscaping projects. Geology, Soils, and Seismicity Implementation of the MM-GEO-1 Prior to development aAbmittal of Prior to Construction Proposed Project could of projects that involve ground technical report. discretionary contractor; cause adverse impacts disturbance or excavations in City of 32 Page 323 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact Mitigation Measure Method of Verification Timing of fb�ponsibility for Verification Complete Verification Verification Date Initial on paleontological undisturbed native soils, the project project Diamond Bar resources. proponent shall retain a paleontologist approval. Community meeting the S%ciety of Vertebrate Development Paleontology's standards for qualified Department professional paleontologist (S1/P, 2010) to conduct an paleontological resources assessment including: a site -specific database search at the Natural History Museum of Los Angeles County and/or other appropriate facilities (such as the University of California Museum of Paleontology); geologic map and scientific literature review; a pedestrian field survey, where deemed appropriate by the qualified professional paleontologist; assessment of the project area's paleontological sensitivity and paleontological monitoring requirements (locations, depths, duration, timing); and preparation of a technical report that documents the methods and results of the study. The report shall be prepared prior to the City of Diamond Bar's approval of project plans and publication of subsequent CEQA documents. Implementation of the MM-GEO-2 The City shall require Sibmittal of findings Prior to Construction Proposed Project could paleontological resources monitoring and documentation, discretionary contractor; cause adverse impacts for any project that has a high potential followed by project City of on paleontological for encountering subsurface monitoring report. approval. Diamond Bar resources. paleontological resources. The location, Community depths, duration, and timing of Monitoring Development monitoring shall be determined by the report shall Department qualified professional paleontologist 33 Page 324 of 328 Mitigation Monitoring and Reporting Program for the City of Diamond Bar General Plan 2040 and Climate Action Plan 2040 Impact KTJ1 Mitigation Measure based on the sensitivity assessment in the study required as part of MM-GED- 1. Prior to the start of ground disturbance, the project proponent shall retain a qualified monitor meeting the Society of Vertebrate Paleontology's standards for paleontological resource monitors (SVP, 2010), and who shall work under the direct supervision of the qualified professional paleontologist. In the event that paleontological resources are unearthed during ground - disturbing activities, the monitor shall be empowered to halt or redirect ground - disturbing activities away from the vicinity of the discovery until the qualified professional paleontologist has determined its significance and provided recommendations for preservation in place or recovery of the resource. The monitor shall keep daily logs detailing the types of activities and soils observed, and any discoveries. After cessation of ground disturbance, the qualified professional paleontologist shall prepare a report that details the results of monitoring. Method of Verification Timing of Verification be prepared after cessation of ground disturbance. fb�qon§bility for Verification Complete Verification Date Initial Page 325 of 328 Agenda Item #: 8.1 Meeting Date: February 24, 2026 PLANNING COMMISSION AGENDA REPORT TO: Chair and Members of the Planning Commission FROM: Greg Gubman, Community Development Director SUBJECT: Project Status Report RECOMMENDATION: Staff recommends the Planning Commission receive and file the Project Status Report dated February 24, 2026. BACKGROUND/DISCUSSION: The Project Status Report has been prepared and is being presented for receipt and filing. PREPARED BY: Arlene Laviera, Administrative Coordinator, Community Development ATTACHMENTS: 02-24-26 project Page 326 of 328 Project Status Report February 24, 2026 CITY OF DIAMOND BAR COMMUNITY DEVELOPMENT DEPARTMENT PROPERTY LOCATION PLANNING COMMISSION REVIEW File # AP Applicant PC CC PC CC PC CC 02/24/26 03/03/26 03/10/26 03/17/26 03/24/26 04/07/26 Annual General Plan Status Report for N/A GL City of Diamond Bar D 2025 Citywide Objective Design Standards DCA PL2024-51 MN City of Diamond Bar PH 22104 Rim Fire Lane DR PL2025-55 RL Pete Volbeda PH New Single -Family Residence ADMINISTRATIVE REVIEW Property Location File # AP Applicant PENDING ITEMS Property Location File # AP Applicant Status 2720 Broken Feather DR PL2025-34 MN Yao Pan First incomplete letter sent 5/27/25 — waiting for additional information (New Single -Family Residence) 1741 Derringer Lane DR PL2025-62 MN Ralph Poon First incomplete letter sent 9/11/25 — waiting for additional information (New Single -Family Residence) 2001 Derringer Lane TPM 83036 MN Gurbachan S. Juneja Fifth incomplete letter sent 7/30/24 - waiting for additional information 2-lot subdivision PL2021-46 Gentle Springs Ln. and SB 330, DR & TTM GL Tranquil Garden LLC Under review S. Prospectors Rd. PL2025-77 (36-unit for sale development with Affordable Units 2583 Indian Creek DR PL2025-67 MN Mike Lou Second incomplete letter sent 1/20/26 — waiting for additional information New sin le-familyresidence 2595 Indian Creek DR PL2025-66 RL Mike Lou Second incomplete letter sent 1/16/26 — waiting for additional information New sin le-familyresidence 1400 Montefino Ave (49-unit for -sale GPA, ZC, TTM, DR, & MN Sarah Klaustermeier Under review development) CUP PL2025-29 23007 Ridge Line DR PL2025-27 MN Terry Chang Second incomplete letter sent 1/7/26 — waiting for additional information New sin le-familyresidence 23901 Ridge Line 2-lot Subdivision TPM PL2022-119 DT/MN Pete Volbeda Third incomplete letter sent 8/20/25 — waiting for additional information LEGEND PH = PUBLIC HEARING AP = ASSIGNED PLANNER PC = PLANNING COMMISSION CC = CITY COUNCIL D = DISCUSSION ITEM Page 327 of 328 Project Status Report CITY OF DIAMOND BAR Page 2 February 24, 2026 PENDING ITEMS (continued) Property Location File # AP Applicant Status 2867 Shadow Canyon DR PL2025-47 RL Alan Gao Under review (Addition and remodel to single-family residence SB9 & Reasonable Accommodations DCA PL2019-43 MN City of Diamond Bar Under Review Ordinance 20857 Quail Run MCUP & PP PL2026-05 RL Luo Yan Under Review (Two-story addition to legal nonconforming residence Page 328 of 328