TO: PLANNING COMMISSION
FROM: BRAD JOHNSON, COMMUNITY DEVELOPMENT DIRECTOR
DATE: MAY 19, 2026
SUBJECT:
Title
REVIEW OF THE PROPOSED AMENDMENT TO THE CLAREMONT MUNICIPAL CODE PERTAINING TO ACCESSORY DWELLING UNITS (ADUS) (#24-CA01). CITY-INITIATED
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SUMMARY
In response to a December 2025 request from the California Department of Housing and Community (HCD), the City has initiated a proposed amendment to the Claremont Municipal Code (CMC) pertaining to Accessory Dwelling Units (ADUs). The amendment is intended to incorporate a large number of revisions to California State ADU law designed to encourage and expand the construction of ADUs.
After a great deal of public comment and participation by both the Architectural and Preservation and Planning Commissions during 2018 and 2019, the City Council approved a major revision to the City’s existing ADU ordinance designed to address state code revisions, codified as Chapter 16.333. At about the same time that the City’s new ordinance was first taking effect, the State Legislature passed a number of additional revisions to ADU law that went into effect at the beginning of 2020. In response, the City revised its ADU ordinance once again, to address the new mandates (“2020 Revise”). The new state revisions allowed for more and larger ADUs than were previously permitted and compelled the City to further amend the CMC in order to comply with new legal requirements. Those changes were incorporated into the previously approved Chapter 16.333, which is now being further updated to address additional changes to State ADU law that have been passed on an annual basis since 2020.
While the draft ordinance attempts to preserve the intent of the original CMC Chapter 16.333, which was the result of considerable deliberation, the amount of City discretion regarding ADUs has been considerably eroded. The new changes include, but are not limited to, time frames for approving ADU applications, permitting of more and taller ADUs on most residential and mixed use lots, clarifications in the location, height and floor area of ADU’s and Junior Accessory Dwelling Units (JADUs) on all properties zoned for residential use, and revising how ADUs are permitted on properties zoned for multifamily use.
With an understanding of the relative lack of flexibility afforded to the City as a result of new legal requirements, the Planning Commission is being asked to review and make a recommendation to the City Council for approval of the proposed code amendment that would revise CMC Chapter 16.333 - Accessory Dwelling Units in accordance with State law.
RECOMMENDATION
Recommended Action
Staff recommends the Planning Commission:
A. Approve A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF CLAREMONT, CALIFORNIA, RECOMMENDING THE CITY COUNCIL ADOPT AN ORDINANCE AMENDING CLAREMONT MUNICIPAL CODE CHAPTER 16.333 - ACCESSORY DWELLING UNITS (#24-CA01); and
B. Find this item is exempt from environmental review under the California Environmental Quality Act (CEQA).
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ALTERNATIVES TO RECOMMENDATION
In addition to the above recommendation, the following alternatives have been identified:
A. Approve the attached resolution with changes as agreed upon by the Planning Commission.
B. Continue the item for additional information and schedule the proposed code amendment for review at a future meeting of the Planning Commission.
BACKGROUND
Accessory Dwelling Units, or “ADUs” for short, are secondary, independent facilities located on a property having a residential unit or units. Significant legislation passed at the State level in 2016, 2016, 2017, 2018, and 2019 that prompted the City to initiate ADU code amendments in 2019 and 2020. Since the 2020 code amendment, The State Legislature has continued to pass additional changes to ADU law on an annual basis including:
• Senate Bill 1030 (effective September 25, 2020);
• Senate Bill 1371 and Assembly Bill 3182 (both effective January 1, 2021);
• Assembly Bill 345 (effective January 1, 2022);
• Assembly Bill 2221 and Senate Bill 897 (both effective January 1, 2023);
• Assembly Bills 976 and 1033 (both effective January 1, 2024);
• Senate Bill 477 (effective March 25, 2024);
• Assembly Bills 834 and 1211 (effective January 1, 2025); and
• Senate Bill 543 and Assembly Bill 1170 (effective Januar 1, 2026);
On December 5, 2025, HCD sent a letter to the City summarizing all changes to ADU Law since 2019 and requested that the City either amend its ordinance to comply with the changes or repeal its ordinance to provide clarity for ADU applicants who may otherwise rely on the outdated ordinance. A copy of this letter is Attachment B. In response, City concluded it was better to amend rather than repeal its ordinance and provided a timeline for the amendment, which HCD has approved. This Planning Commission review is contained in that schedule.
The 2019 major ADU revision (Ordinance #2019-07) was crafted over the course of many months with considerable input from the City Council, the Planning Commission, Architectural and Preservation Commission, and the public. The ordinance changed how ADUs were regulated in Claremont but retained discretionary design review over many ADU applications. Almost immediately after that ordinance became effective, additional changes were made to state ADU that included elimination of any type of discretionary review as well as eliminating planning review fees on most ADUs.
ADU Development Trend
Encouraging massive increases in the development of ADUs and JADUs is a significant component of the State’s approach to solving the statewide housing shortage. Prior to the 2018 legislation, the City had very few ADUs and processed an average of approximately one ADU application per year. With the 2019 revision, the City saw a significant increase in the number of ADU applications submitted due to relaxed regulations coupled with growing public awareness and acceptance of ADUs. With the 2020 revision, ADU applications continued to grow to as many as 66 applications received in 2022. The vast increase is likely a result of soaring housing costs as homeowners sought ways to augment income to pay high mortgages and renters sought affordable places to live. ADU applications received by the Planning Division over the last several years are listed below:
Analysis
This analysis section is a summary of the more substantive changes contained in the draft Code Amendment, generalized on a topic-by-topic basis. For continuity, language is also included regarding past City policies and general concepts that relate to the topic as needed. For a more detailed description of the revisions, the reader is directed to the HCD request letter (Attachment B), which includes a five-page summary of the changes. The reader is also directed to the 2026 HCD Accessory Dwelling Unit Handbook (Attachment C), which has an even more detailed description of the various components of State ADU Law and how they are implemented by state code.
Junior Accessory Dwelling Units (JADUs)
The 2026 draft Code Amendment deletes language that requires JADUs to include and existing bedroom of the primary residence and adds language to Section 16.333.060.C.(5) that allows JADUs to be constructed within an attached garage, which had not been previously specified.
JADUs are dwelling units of up to 500 square feet in area that are created out of space contained within an existing residence. JADUs are required to have their own cooking and sleeping accommodations but may share a bathroom within the main residence. The City’s 2019 ordinance did not permit JADUs whatsoever. 2019 State legislation required that JADUs be allowed by right on all single-family residentially developed properties. Development standards for JADUs were included in the City’s 2020 revision (Attachment D). Much of this language remains along with the revised language is contained in Section 16.333.060. Overall adoption of JADUs has been limited to a relatively small number and make up approximately 5% of ADU applications. These JADU changes are anticipated to have a modest impact in Claremont and seem sensible for the type of unit.
Objective Design Standards
While most of the standards for ADUs are dictated by State ADU law, municipalities are still able to apply certain objective design standards for ADUs, which must be applied through a ministerial review process. This means design requirements must be purely objective and not leave room for interpretation by decision makers. In the past, Claremont has depended heavily on subjective design review standards in its design review processes; requiring staff and commissions to use judgement when approving projects. These types of review procedures are viewed by the state as problematic and barriers to housing development as they often make zoning rules difficult for applicants to understand, can be capriciously applied, and can be used to deny deserving projects based on personal opinions of the decision makers.
Generally, all of the discretionary review standards for ADUs were removed in the 2020 revision to focus more on objective standards. The new objective standards included matching the ADU design to the existing primary residence and limiting ADUs to single story and use of clerestory windows that are a minimum of six feet above the floor on those sides to protect privacy for neighbors.
The draft 2026 Code Amendment allows additional design options for ADUs that comply with the City’s pre-approved ADU design program. It also relaxes the clerestory window requirement in many situations. The clerestory window requirement has been a concern for many applicants in the past and has proved to be limiting due to Building Code requirements regarding fire egress. The draft Code Amendment also includes language further clarifying that only objective design standards apply to the review of ADU and JADU applications.
Height
State law has been revised to allow a maximum height of up to 18 feet of height for freestanding ADUs and two stories for ADUs that are attached to existing two-story structures. The City’s current ordinance included a maximum permitted ADU height of 16 feet with ADUs not to have more than one story. The CMC generally requires that the height of buildings be measured as the distance between adjacent grade and the midpoint between a gable or hip roof’s eaves and its highest ridge. This allows for the maximum height of a building having such a roof to exceed 15 feet (for buildings with flat roofs height is measured as the vertical distance between adjacent grade and the highest point of the building).
In order to address the discrepancy between the State-mandated maximum permitted height for ADUs of 16feet and the CMC-required maximum permitted height for detached accessory structures, staff has included a definition of height in the proposed ordinance that will help ensure that new detached ADUs are more consistent with other accessory structures in terms of their height. Height, for the purposes of CMC 16.333, is proposed to be measured as the vertical distance between adjacent grade and the highest point of the structure (Section 16.333.010.G).
Claremont’s 2019 ADU ordinance permitted ADUs up to two-stories in height subject to the alternative discretionary review track, which required review of the proposal by the Architectural and Preservation Commission. When the 2020 revision occurred, the discretionary review track was deleted in its entirety because all review needed to be ministerial. The one-story limitation is no longer available. The 2026 revision allows for two-story ADUs that are attached to an existing two-story structure.
Parking
As was the case in the City’s 2020 ADU ordinance, ADUs have a one-car parking requirement, unless certain criteria are met. Parking for an ADU may be uncovered; it need not be located in a covered garage or carport. The existing ordinance allows for an existing garage to be converted into an ADU without having to replace the two parking spaces required for the primary dwelling. Generally, most Claremont homes have an existing driveway that can still be used for parking cars on a site. Nearly all have a capacity for two cars and more if parked in tandem arrangements (one car behind another). Properties with two-car garages and no driveway parking capacity are rare in Claremont and are generally limited to townhome condominiums and homes with real alley access. Homes with no driveway parking capacity have less incentive to convert their garage due to the City’s overnight parking restrictions. Overall, parking requirements for ADUs remain relatively unchanged from the City’s 2020 ADU ordinance and have not proven to be problematic for nearly all ADU applications.
Application Review
State law requires that ADU applications be reviewed and approved in 60 days or less. A new requirement to provide completeness determinations within 15 business days is designed to further expedite the review process. The condensed review timeline mandated by State has not been a major problem for City reviews. Most of the exceptions involve very long lead times for resubmittals from applicants or multiple incomplete submittals.
BASIS FOR RECOMMENDATION
Staff finds that the draft ordinance, which would again amend CMC Chapter 16.333 - Accessory Dwelling Units complies with the States new legal requirements that have become state law since the last ADU code amendment in February 2020. While the new ordinance removes several of the remaining City requirements that were included in the City’s 2019 ordinance pertaining to ADUs, it maintains some City controls through objective design standards, primarily through requirements that the ADU match certain features of the primary residence and adds flexibility to use the City’s new preapproved ADU plans. Together with statewide height, setback and interior feature requirements, this ordinance is expected to continue to ensure that new ADUs will be appropriately integrated into the urban fabric of the City’s neighborhoods.
FINANCIAL REVIEW
The cost to review the HCD request letter and prepare and review the draft Code Amendment pertaining to ADUs (#24-CA01) is estimated at $6,500 and is included in the operating budget of the Community Development Department.
CEQA REVIEW
The proposed Code Amendment pertaining to ADU’s is statutorily exempt from the provisions of CEQA pursuant to Section 15282(h) of the Public Resources Code that exempts the adoption of an ordinance regarding ADUs by cities and counties that implement the provisions of Section 65852.2 of the California Government Code (now codified as Government Code Section 66310 et seq.). Therefore, no further environmental review is necessary.
PUBLIC NOTICE PROCESS
On Friday, April 24, 2026, notice of the public hearing was published in the Claremont Courier as a display ad. The agenda and staff report for this item have been posted on the City website and distributed to interested parties. If you desire a copy, please contact Nhi Atienza at natienza@claremontca.gov.
Note: As of January 1, 2025, California law (AB 2904) requires cities to provide at least 20-day notice for public hearings on zoning ordinances or amendments that affect the permitted uses of real property. This is an increase to the previous 10-day requirement.
Submitted by: Prepared by:
Brad Johnson Christopher Veirs
Community Development Director City Planner
Attachments:
A - Draft Resolution Recommending CC Approval of Code Amendment
B - HCD Letter Requesting Update to the City ADU Ordinance
C - HCD Accessory Dwelling Unit Handbook (Revised 3/2026)
D - CMC Chapter 16.333 Accessory Dwelling Units (Adopted 2/2020)
E - City Council Ordinance No. 2020-02