DATE: August 18, 2025
TO: Mayor and Members of the City Council
VIA: Stefan Chatwin, City Manager
Marlene Subhashini, Assistant City Manager
FROM: Sofia Mangalam, Community Development Director
Thai-Chau Le, Planning Manager
Kevin McGill, Assistant Planner
DEPARTMENT: Community Development
SUBJECT: AMENDING TITLE 17, “ZONING” OF THE FOSTER CITY MUNICIPAL CODE, MAKING REVISIONS TO CHAPTER 17.78
ACCESSORY DWELLING UNITS TO ENSURE COMPLIANCE
WITH STATE LAW RELATED TO ACCESSORY DWELLING UNITS
(ADUS)
RECOMMENDATION
It is recommended that the City Council introduce by title only and waive further reading of the proposed Ordinance making various text amendments to Title 17, “Zoning” of the Foster City Municipal Code - Chapter 17.78 - Accessory Dwelling Units to ensure compliance with state law related to Accessory Dwelling Units (ADUs) and finding the proposed amendments are exempt under California Environmental Quality Act (CEQA) Guideline Section 15061(b)(3) – Common Sense Exemption and Public Resources Code Section 21080.17.
EXECUTIVE SUMMARY
Foster City’s Housing Element 2023-31 includes goals, policies, and programs to provide additional housing in a way that is balanced with the community’s desires to retain the aspects of Foster City that make it a great place to live, work, and play. The Housing Element Programs include the City’s commitment to timeframes for implementation to continuously update the ADU ordinance to comply with new state laws.
One of the Housing Element Programs pertaining to ADUs is:
H-D-4-a: ADUs - Continue implementation of Chapter 17.78, Accessory Dwelling Units.
Update the City’s ADU ordinance to comply with state laws by December 2023 and subsequently update the City’s regulations to comply with new state laws within six months of being effective.
Responsible Agency: Community Development Department
Timeframe: Update Chapter 17.78 to comply with 2023 state laws by December 2023 and update the City’s regulations to comply with subsequent new state laws within 6 months of being effective.
Quantifiable Objectives: 24 ADUs by 2031
Funding Source: General Plan Maintenance Fund
Geographic Targeting: Promote programs to expand housing choices in single- family areas
Since the adoption of the Housing Element 2023-31, Chapter 17.78, Accessory Dwelling Units, in the Foster City Municipal Code (FCMC), has been amended multiple times to implement the program, H-D-4-a, as follows:
File No. RZ2023-0006 / PC Resolution No. P-11-23 / City Council Ordinance No. 669 / September 18, 2023 City Council Meeting;
File No. RZ2024-0001 / PC Resolution No. P-04-24 / City Council Ordinance No. 677/ March 20, 2024 City Council Meeting; and
File No. RZ2024-0012 / PC Resolution No. P-23-24 / City Council Ordinance 684 / November 18, 2024 City Council Meeting.
Foster City’s ADU Ordinance was last amended on December 2, 2024, via Ordinance 684 to comply with state laws. However, additional amendments are required for further clarification.
On July 17, 2025, the Planning Commission held a public hearing to review the draft Ordinance amending FCMC Chapter 17.78 Accessory Dwelling Units to ensure compliance with state law related to ADUs. At the meeting, the Planning Commission voted 4-0-0-1 (1-absent) to adopt Resolution P-09-25 (Attachment 2), recommending that the City Council approve amendments to FCMC Chapter 17.78 to ensure compliance with state law related to ADUs, and finding the proposed amendments exempt under CEQA.
The draft Ordinance is attached as Exhibit A of the Resolution (Attachment 1) for the City Council’s consideration.
BACKGROUND
The California State Legislature continues to pass new laws aimed at easing California’s housing crisis by continuing to limit local government discretion over housing development projects, and these laws are intended to increase the housing supply. In 2024, three (3) new state laws were passed pertaining to ADUs.
1. Senate Bill (SB) 477: On March 25, 2024, SB 477 was signed into law by Governor Newsom to amend Sections 714.3 and 4751 of the California Civil Code. SB 477 consolidates ADU/Junior ADU (JADU) law, previously scattered across five (5) sections of the Government Code, specifically 65852.2, 65852.22, 65852.23, 65852.26, and 65852.150, into a single, unified Chapter 13 of Division 1 of Title 7 of the Government Code. The new Chapter 13 Accessory Dwelling Units, is divided into four (4) articles, and each article is further divided into various sections, including Article 1 – General Provisions, Article 2 – ADU Approvals, Article 3 – JADUs, and Article 4 – ADU Sales. The bill went into effect on March 25, 2024.
The bill's goal is to make the law easier to read and navigate by dividing key regulations into smaller sections by topic area. The bill also makes non- substantive conforming amendments to other sections of housing law to reflect ADU/JADU laws.
Staff Comments: It shall be noted that the text amendments pertaining to this bill have already been incorporated last year via Ordinance 684. However, there is one (1) new reference added under the new definitions.
2. Senate Bill 1211: On September 19, 2024, SB 1211 was signed into law by Governor Newsom and is known as the Land Use – Accessory Dwelling Unit Ministerial Approval Bill.
Replacement Parking: The bill prohibits local agencies from requiring the replacement of off-street parking spaces if an uncovered parking space is demolished in conjunction with the construction of, or is converted to, an ADU.
Livable Space: This bill defines “livable space” for purposes of the provisions governing ADUs to mean a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation. Multi-family ADUs: This bill authorizes up to eight (8) detached ADUs to be created on a lot with an existing multifamily dwelling, provided that the number of ADUs does not exceed the number of existing units on the lot, and up to two (2) detached ADUs on a lot with a proposed multifamily dwelling. The bill allows ministerial approval for ADUs and JADUs and sets limitations for local municipalities when requiring objective design standards and allows certain units by right. “State Exempt ADUs” include one (1) detached ADU up to 800 square feet (SF), one (1) JADU up to 500 SF, and/or one (1) conversion ADU on single-family properties.
Staff Comments: Some of the text amendments pertaining to this bill were previously incorporated into Chapter 17.78 via Ordinance 684. However, a few further amendments have been included in the proposed text amendments to provide clarification regarding state-exempt ADUs.
3. Assembly Bill (AB) 2533: On September 28, 2024, AB 2533 was signed into law and took effect on January 1, 2025. This bill expands the amnesty program for legalizing unpermitted ADUs and JADUs as follows:
Prohibits a local agency from denying a permit for an unpermitted ADU or JADU that was constructed before January 1, 2020, for those violations, unless the local agency makes a finding that correcting the violation is necessary to comply with conditions that would otherwise deem a building substandard. Requires a local agency to inform the public about the provisions prohibiting denial of a permit for an unpermitted ADU or JADU, and that the information includes a checklist of the conditions that deem a building substandard and to inform homeowners that, before submitting a permit application, the homeowner may obtain a confidential third-party code inspection from a licensed contractor.
Prohibits a local agency from requiring a homeowner to pay impact fees or connection or capacity charges except under specified circumstances. Authorizes an inspector from a local agency, upon receiving an application for a permit for a previously unpermitted ADU or JADU constructed before January 1, 2020, to inspect the unit for compliance with health and safety standards and provide recommendations to comply with health and safety standards. Prohibits the local agency from penalizing an applicant for having the unpermitted ADU and requires the local agency to approve necessary permits to correct noncompliance with health and safety standards.
Staff Comments: It shall be noted that no text amendments are being proposed pertaining to this bill. To comply with the state law, staff has created a dedicated webpage outlining the provisions of the bill and the process for homeowners to apply for permits to legalize their unpermitted ADUs/JADUs. Please refer to this webpage: Unpermitted ADUs and AB 2533 Applicability | Foster City California
PREVIOUS MEETINGS
Joint City Council/Planning Commission Special Meeting
A Joint City Council and Planning Commission Special Meeting was held on June 9, 2025, providing the City Council and Planning Commission with an overview of 2025 Land Use and Housing Legislative Updates. Special Legal Counsel, Eric Philips, presented significant housing and land use bills adopted by the California Legislature, including the three (3) ADU bills discussed above. Please click the link for the Meeting Minutes.
Planning Commission Public Hearing
On July 17, 2025, staff presented draft amendments to FCMC Chapter 17.78 to align with state laws pertaining to ADUs for the Planning Commission’s consideration.
Commissioner Jagtiani asked the following questions of staff:
Are there any objective design standards for ADUs in multi-family properties? Staff noted that the only objective standards for multifamily ADUs would be those previously established in the code, including height, setback, and location. Are state exempt ADUs defined by size? Is anything up to 800 SF considered state exempt?
Staff noted that state exempt ADUs are distinguished primarily by the size and type of ADU. Staff provided a PowerPoint slide that highlighted the main criteria.
Those size limitations included requirements for single-family detached ADUs, JADUs, and conversion ADUs as well as multi-family detached ADUs and conversion ADUs. (Those requirements are listed below.) Special Legal Counsel Eric Phillips noted that in addition to the size, the state exempt ADUs are also subject to height and setback limitations. Clarification regarding extension of up to 150 SF for JADUs, which is being removed.
Staff noted that the purpose of this revision was to avoid any inconsistencies or conflicts with existing state laws and state guidance.
Special Legal Counsel Phillips clarified that state law permits for the construction of JADUs to be entirely within existing structures, and Department of Housing and Community Development (HCD)’s written guidance notes that the 150 SF expansion is required to be added for conversions to create ADUs and not to be used to create JADUs and that the JADU needs to be limited to the existing structure to be consistent with the state guidance.
Clarification that the provision to allow an 850 SF ADU in the front yard of a single- family property is allowed on multi-family properties.
Staff noted that the commissioner’s understanding was correct. If the property site does not allow for the construction of at least an 850 SF ADU, then a portion or all of that ADU would be permitted to be constructed in the front yard of a multi-family property. Staff confirmed this would be allowed for both single and multifamily- zoned properties.
Commissioner Kenkre asked the following questions of staff:
Asked for clarification that an 850 SF addition to the house would be considered an ADU?
Staff noted that an ADU is intended to be a separate living space from the primary dwelling. The type of ADU can vary in the location being in the garage, as a conversion, attached, or detached. There is a difference between an addition and an attached ADU as the attached ADU would be a stand-alone living unit that has a separate entrance and kitchen.
Commissioner Stoveland noted that he appreciates that staff is recommending the text amendment for “completed” application to “complete” application in Section 17.78.090.A of the Foster City Municipal Code as he feels the current code could create confusion.
There were no written or verbal public comments during or prior to the July 17 Planning Commission meeting.
After deliberation, a motion was made by Commissioner Jagtiani, seconded by Commissioner Kenkre, to recommend that the City Council adopt an Ordinance amending Title 17, “Zoning” of FCMC Chapter 17.78, “Accessory Dwelling Units” to ensure compliance with state law related to ADUs and finding the proposed amendments exempt under CEQA Guideline Section 15061(b)(3) – Common Sense Exemption and Public Resources Code Section 21080.17, passed by roll call 4-0-0-1 (Absent: Chair Pedro).
ANALYSIS
NOTICING/PUBLIC OUTREACH
The public was advised of this meeting in the following ways:
Notice of the public hearing in the Foster City Islander – August 6, 2025 Foster City website: www.fostercity.org – July 31, 2025 Posting at all Public Posting Places – July 31, 2025
Noticing to Planning Listserv – August 6, 2025
AMENDMENTS TO FCMC SECTION 17.78.040 – DEFINITIONS
Added the following new definitions:
G. “High-quality transit corridor” means a corridor with fixed route bus service with service intervals no longer than fifteen minutes during peak commute hours. M. “Objective standards” means 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 prior to submittal. P. “State Exempt Units” means an ADU or JADU that is constructed pursuant Government Code section 66323 and is not subject to Government Code sections 66314-66322. These units are exempt from the requirements set forth in Foster City Municipal Section 17.78.060.F.
Q. “Tandem parking” means that two or more automobiles are parked on a driveway or in any other location on a lot, lined up behind one another.
Staff Comments: The amendments include four (4) new definitions that will provide consistency and clarity with state laws for the residents, applicants, and plan reviewers.
The addition of “Objective standards” and “State Exempt Units” are aimed at aligning the City’s code to SB 1211, which specifically restricts local municipalities from requiring objective design standards for ADUs that are deemed to be exempt. State Exempt ADUs are limited to specific standards per California Government Code Section 66323 as outlined in the California Department of Housing and Community Development Accessory Dwelling Unit Handbook. State Exempt ADUs include:
Single-Family State Exempt ADUs (any combination of the following) Detached ADUs (800 SF or less)
JADUs (500 SF or less)
Conversion ADUs
Multi-Family State Exempt ADUs
Detached ADU
oUp to 8 units on an existing multi-family development
Shall not exceed the existing number of units on the lot oUp to 2 units for proposed multi-family development
Conversion ADUs
oWithin existing non-livable space (i.e., gyms, enclosed parking, etc.) oUp to 25% of the existing dwelling units
AMENDMENTS TO FCMC SECTION 17.78.060 – STANDARDS APPLICABLE TO
SINGLE-FAMILY ZONING DISTRICTS
Changes to this section include:
Added two (2) more options:
oOption 6 – One JADU (up to five hundred SF); and one newly constructed ADU (up to 850 SF).
oOption 7 – One conversion ADU; and one newly constructed ADU (up to 850 SF).
Increased the minimum square footage of an allowable ADU from 800 SF to 850 SF throughout this section.
Added an exception clause under Section 17.78.060.F to specify that the additional requirements did not apply to State Exempt ADUs and JADUs.
Staff Comments: The amendment to include Options 6 and 7 is intended to provide all the possible combinations of options for applicants. These options are currently available under the City’s Code under Option 3 but were not previously spelled out in the Code.
This change is only administrative and does not allow more or further restrict what is currently allowable to applicants. Furthermore, these existing options in the City’s Code encompass those that are deemed “State Exempt” and therefore, no separate options for State Exempt ADUs need to be added to the Code.
The change from 800 SF ADU to 850 SF in FCMC Sections 17.78.060.A.3.c,
17.78.060.A.4.b, 17.78.060.C.2, and 17.78.060.D.2 is to be consistent with California Government Code Section 66321(b)(2)(A) for local municipalities to allow at least an 850 SF ADU. FCMC Section 17.58.060.F was revised to include language to clarify that State Exempt ADUs would be exempt from the objective design requirements.
AMENDMENT TO FCMC SECTION 17.78.070 – STANDARDS APPLICABLE TO THE
MULTIFAMILY RESIDENCE ZONING DISTRICTS
Section 17.78.070 of the FCMC lists the requirements for multi-family ADUs. It allows:
1. Conversions of non-livable space up to 25% of the existing number of multifamily units, and
2. Up to eight (8) detached ADUs provided that the total number of ADUs does not exceed the existing number of multi-family units, or
3. Up to two (2) detached ADUs on a lot with a proposed multi-family dwelling.
However, further changes are proposed below to be consistent with updated practices and implementation interpretations for ADUs on multi-family properties:
Removal of the size requirements for detached ADUs in the multi-family section.
Revision of the height requirements for detached ADUs to allow a height of 18’ with an exception to add up to 2’ of height to accommodate a roof pitch to align with the pitch of the primary multifamily dwelling (20’ max). Added language to allow attached ADUs, including requirements for setbacks, height, colors, size, and locations for existing multi-family development.
Staff Comments: These text amendments are consistent with the updated interpretation of state laws to ADUs in multi-family developments.
Specifically for detached ADUs, the size requirement for detached ADUs located on an existing multi-family development was removed, because the current state law does not set any size limitations per SB 1211 requirements for local municipalities. Height language was revised for clarity and consistency with the current state laws. Furthermore, these types of ADUs on multi-family properties would be considered “State Exempt” and would be consistent with the new definition proposed in Section 17.78.040. These State Exempt ADUs would be subject to design standards within Government Code Section 66323 since the City’s Code does not currently include objective design standards for multi-family ADUs.
For attached ADUs, new language to specify the allowability of attached ADUs to multi- family developments was added to be consistent with requirements for local municipalities to allow up to one (1) attached ADU. With the new code to allow an attached ADU on multi-family development, the City added design requirements to guide the development of future potential projects, and to be consistent with the minimum requirements already allowed for single-family attached ADUs.
AMENDMENTS TO FCMC SECTION 17.78.080 – PARKING REQUIREMENTS FOR
ACCESSORY DWELLING UNITS
Changes to this section include:
Added clarifications that parking is not required for an ADU when an application is received for a new single-family dwelling or new multi-family dwelling with an ADU on the same parcel, provided that the submittal meets all requirements per California Government Code 66322.
Other administrative and clerical changes for clarity and consistency for applicants and readers.
Staff Comments: The amendment to clarify parking would not be required for an ADU when the ADU is part of a submittal in conjunction with a new single-family dwelling or new multi-family dwelling on the same lot. The other text amendments in this section are only intended to provide clarification.
AMENDMENTS TO FCMC SECTION 17.78.090 – PERMIT PROCESS
Changes to this section include:
Changed “completed application” to “complete application” to clarify the timing of when an ADU permit should be approved by staff. An ADU permit shall be approved within thirty days from the date staff receives a complete application. Other administrative and clerical changes for clarity and consistency for applicants and readers.
Staff Comments: The minor amendment from “completed application” to “complete application” is to reduce misinterpretation on when the 30-day review and approval of an ADU application and proposal would begin. This text amendment aimed to clarify to applicants that the 30-day clock will begin after the application submittal includes all the necessary documents staff need to ensure the project complies with Foster City’s ADU requirements and state laws and is deemed “complete” by staff, rather than just a signed application without any necessary information for staff to begin review.
CEQA
The proposed actions would update the City’s existing Municipal Code to align with the requirements of the most recent updates to the state’s laws. The actions would not result in physical changes to the environment. Pursuant to CEQA Guidelines Section 15061(b)(3) – Common Sense Exemption. Additionally, Public Resources Code Section 21080.17 states that CEQA does not apply to the adoption of an ordinance to implement the provisions of Article 2 (commencing with Section 66314) or Article 3 (commencing with Section 66333) of Chapter 13 of Division 1 of Title 7 of the Government Code. which means that adoption of this ordinance to update the Municipal Code to implement State ADU and JADU law is statutorily exempt from CEQA.
FISCAL IMPACT
There is no fiscal impact related to this item except for the staff time spent on the preparation of the Ordinance.
CITY COUNCIL VISION, MISSION, AND VALUES/PRIORITY AREA
Smart Planning, Development, and the Local Economy
ATTACHMENTS:
Attachment 1 – Ordinance
Attachment 1a – Exhibit A
Attachment 2 – Planning Commission Resolution P-9-25 with Text Amendments (Redlined)