DATE: June 15, 2026
TO: Mayor and Members of the City Council
VIA: Stefan Chatwin, City Manager
Marlene Subhashini, Assistant City Manager
FROM: Sofia Mangalam, Deputy City Manager
Thai-Chau Le, Interim Community Development Director
Kevin McGill, Associate Planner
DEPARTMENT: Community Development Department
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 Chapter 17.78 “Accessory Dwelling Units” of Title 17, “Zoning” of the Foster City Municipal Code (FCMC) to ensure compliance with State laws related to Accessory Dwelling Units (ADUs) and finding the proposed amendments 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 ADU code updates 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 Foster City Municipal Code (FCMC), has been amended multiple times to implement the program, H-D-4, 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
File No. RZ2024-0012 / PC Resolution No. P-23-24 / City Council Ordinance 684 / November 18, 2024 City Council Meeting and,
File No. RZ2025-0004 / PC Resolution No. P-09-25 / City Council Ordinance 692 / August 18, 2025 City Council Meeting
Foster City’s ADU Ordinance was last amended on August 18, 2025, via Ordinance No. 692 to comply with State Law. However, further amendments are now required due to changes in California law that became effective October 10, 2025, and January 1, 2026.
In addition, staff are proposing additional edits to provide clarification for both applicants and staff.
On May 21, 2026, the Planning Commission held a public hearing to review the draft Ordinance amending Title 17, “Zoning” of the Foster City Municipal Code revising Chapter 17.78 Accessory Dwelling Units to ensure compliance with State law related to ADUs. During the discussion, one of the Commissioners raised concerns about the deed restriction and owner-occupancy and how these components may restrict future occupancy options and potential sale of ADUs. The concerns included that deed restrictions can create long-term title and resale issues because they run with the land.
Owner occupancy requirement can prove burdensome even if an owner’s circumstances change - such as needing to move into a care facility or wanting to rent both the main house and the JADU.
After deliberation, the Planning Commission voted 4-0-0-1 (1-absent) to adopt Resolution P-11-26 (Attachment 2), recommending that the City Council amend 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 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 with an amendment to deed restrictions requirements pertaining to JADUs included in FCMC Section 17.78.060.B.3, to read as follows: “So long as required by California Government Code Section 66333, or successor code section, the owner must record a deed restriction as outlined in California Government Code Section 66333, which shall run with the land, and shall include the following….” To follow through City’s commitment in the timely implementation of the Housing Element program H-D-4-a, staff is recommending that the City Council introduce by title only and waive further reading of the proposed Ordinance making various text amendments to FCMC Chapter 17.78 - Accessory Dwelling Units. The draft Ordinance is attached as Exhibit A of 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. Four (4) new state laws became effective pertaining to ADUs since the last ADU text amendments in August 2025.
1. California Assembly Bill No. 462: On October 10, 2025, AB 462 was signed into law by Governor Newsom to streamline and accelerate the permitting process for ADUs in certain coastal and disaster-affected areas. These areas include the County of Los Angeles and certain other counties under a Governor’s State of Emergency proclamation.
Staff Comments: Per this bill, there are no areas within the Foster City limits that are identified as coastal or disaster-affected areas per AB 462. Staff is not proposing any text amendments in relation to this bill.
2. California Assembly Bill No. 1154: On October 10, 2025, AB 1154 was signed into law by Governor Newsom to amend California Gov. Code Section 66333 to:
Specify when a JADU has a shared sanitation facility (bathroom) with the primary house, an owner-occupancy is required. If the JADU has independent sanitation facility, then owner-occupancy is not required.
Requires that JADUs cannot be used as short-term rentals (30 days or less). If the JADU is rented, the JADU must be rented for longer than 30 days.
Staff Comments: Some of the text amendments pertaining to this bill are already incorporated into Chapter 17.78. However, a few further amendments to further clarify these requirements are recommended. Specifically, FCMC Sections
17.78.060.B and 17.78.100.A would be updated to address these new State laws to comply with California Department of Housing and Community Development (HCD) requirements to require JADUs only needing to be owner-occupied when there is a shared sanitation facility with the JADU. Previous updates to FCMC Sections 17.78.060 and 17.78.100 have incorporated restriction for JADUs to be used for short-term rentals (leases of less than 30 days) and no additional changes in FCMC are required at this time.
3. California Senate Bill No. 9: On October 10, 2025, SB 9 was signed into law by Governor Newsom and amended California Gov. Code Section 66326 of the California Gov. Code to further clarify that local agencies are required to adopt an ADU ordinance that complies State requirements and to submit the adopted ordinance to the HCD within 60 days of the adopted ordinance. Furthermore, if the HCD finds that the ordinance does not comply with the State standards and provides comments, the local agency shall respond to HCD’s finding within 30 days. If the local agency fails to fix the ordinance or justify compliance, HCD can escalate the issue to the Attorney General, potentially triggering legal action.
Staff Comments: It should be noted that this version of SB 9 effective January 1, 2026, is not the same as the 2022 SB 9 that pertains to lot splits for ADUs. The 2025 SB 9 bill revises Section 66326 to set and clarify local agencies’ requirements to adopt an ordinance for ADUs that meets the States ADU requirements, send the adopted ordinance to HCD for the State to review within 60 days of adoption, and to respond to comments from HCD of non-compliance with 30 days.
No text amendments are being proposed pertaining to this bill as this is a clarification of review procedures for staff. However, pursuant to the requirements of this bill, staff will transmit the adopted Ordinance to HCD following City Council approval.
4. California Senate Bill No. 543: On October 10, 2025, SB 543 was signed into law by Governor Newsom and amended various sections of the State ADU laws (California Gov. Code Sections: 66311, 66313, 66317, 66320, 66321, 66323, 66325, and 66335). These updates include:
A. Standardizing size measurements: All size limits and fee rules are now based on interior livable space. Specifically:
oA revision to the JADU definition to require the size of a JADU to be no more than 500 SF of interior livable space (California Gov. Code Section 66313).
oNo impact fees for ADUs that less than or equal to 750 SF of interior livable space or for JADU that has 500 SF of interior livable space or less. In addition, it requires that impacts fees for ADUs with more than 750 SF of interior livable space be charged proportionately in relation to the square footage of the primary house ( California Gov.
Code Section 66311).
oClarification that an ADU or JADU of less than 500 SF of interior livable space does not increase the assessable space when used in the calculation and imposition of school fees ( California Gov. Code Section 66311).
oRevision of the size limitations of ADUs to be based on the square footage of interior livable space ( California Gov. Code Section 66321).
B. Clearer and faster review process:
oCities must review applications within 15 business days and specify missing items if incomplete (California Gov. Code Section 66317). oApplicants can appeal denials or incompleteness decisions, with a final decision required within 60 business days.
C. Clarification on HCD Oversight:
oIf local agencies fail to comply with state oversight deadlines, state ADU laws override local JADU rules.
oExpansion of HCD’s authority to review, adopt, amend, or repeal guidelines and to additionally grant that authority with respect to terms, references, and standards for ADUs ( California Gov. Code Section 66311).
D. Specification of the number of allowable ADUs allowed on a given parcel (California Gov. Code Section 66323).
E. Clarification that fire sprinklers are not required for a JADU if the primary residence does not have fire sprinklers and that the addition of a JADU cannot trigger the requirement for fire sprinklers ( California Gov. Code Section 66323).
F. Local Ordinance Requirements: Specifies that if a local agency fails to submit an adopted JADU ordinance to HCD within the 60- day timeline or fails to respond to HCD’s findings regarding their ordinance within the 30- day timeline, that ordinance is null and void and the local agency must only apply State ADU Law when processing applications for JADUs ( California Gov. Code Section 66333.5).
Staff Comments: Text amendment to FCMC Chapter 17.78 is recommended to further align the City’s code with this Bill as follows:
oFor item A above, staff recommends adding a definition for interior livable space in FCMC Section 17.78.040 Definitions and Section 17.78.100 Other Provisions.
oFor item B above, staff recommends adding a new Section 17.78.110 Appeal to comply with these new requirements for an appeal process and revised areas in Section 17.78.090 Permit Process to align the 15- and 30- days timeline.
oFor items C and D, no changes are proposed as those only pertain to clarifications of review procedures for staff and the City. oFor item E, no changes are proposed as fire sprinklers requirements have previously been codified in FCMC Section 17.78.100.F.
oFor item F, staff will transmit the adopted Ordinance to HCD following City Council approval.
To implement the Housing Element program H-D-4-a, staff continue to re-examine FCMC Chapter 17.78 in response to new State laws and are proposing a series of text amendments. The recommended text amendments in this round of updates are intended to:
1. Ensure compliance with state laws;
2. Provide additional clarity to support staff implementation of the code; and
3. Reduce potential misinterpretation for applicants.
Full changes are shown in Attachment 1 and summarized under Analysis below.
PREVIOUS MEETINGS
Joint City Council/Planning Commission Special Meeting
A Joint City Council and Planning Commission Special Meeting was held on February 24, 2026, providing the City Council, Planning Commission, and the public an opportunity to review and provide input on the 2026 Land Use and Housing Legislative Updates. The presentation by Special Legal Counsel, Eric Philips, provided an overview of the significant housing and land use bills adopted by the California Legislature, including the four (4) ADU bills discussed above.
The City Council and Planning Commission provided the following comments from Feb 24, 2026 Joint City Council/Planning Commission Meeting:
Clarification for the definition of calendar days and business days if the streamlining 15 calendar days to review new applications for ADUs (1:19.45). Inquiry if the updates to the ADU ordinance would remove the home occupation requirements for JADUs per AB 1154 (1:20:00).
Inquiry if the ADU Ordinance would be updated to include the appeal requirements per SB 543 (1:23:30).
Clarification on the number of ADU units allowed on a single-family lot and if there would still be setback constraints (1:38:20).
Please click the link for the February 24, 2026 City Council/Planning Commission Joint Special Meeting Minutes
Planning Commission Public Hearing
On May 21, 2026, staff presented draft amendments to Chapter 17.78 of the Foster City Municipal Code to align with State laws pertaining to ADUs for the Planning Commission’s consideration. Planning Commission asked clarifications pertaining to frequency of ADU updates needed by local municipalities pertaining to these State’s requirements, authority of Planning Commission to deny or approve changes, and whether the City has received any front-yard ADU requests or inquiries.
One of the commissioners expressed concerns regarding deed restrictions and owner- occupancy requirements, noting that deed Restrictions may create long-term title and resale issues because they run with the land. The commissioner also noted that owner- occupancy requirements can become burdensome if an owner’s circumstances change, such as if the owner needs to move into a care facility or wishes to rent both primary residence and the JADU.
After deliberation, the Commission made a motion to include edits to the Section
17.78.060.B to provide that deed restriction for JADUs will be applicable as long as required by the California Gov. Code Section 66333, or successor code section.
A motion was made by Commissioner Pedro, seconded by Commissioner Jagtiani, and adopted Resolution No. P-11-26 (Attachment 2) recommending the City Council adopt the proposed ordinance with amendments.
ANALYSIS
Staff is recommending the following amendments.
AMENDMENTS TO SECTION 17.78.040 – DEFINITIONS
Clarified and added the following definitions:
Clarified size limitations to interior living space under “Accessory dwelling unit” or “ADU”.
D. “Business Days” means regular days of business operations that excludes Saturday, Sunday, and holidays specified in Gov Code 6700 & 6701. F. “Days” means a calendar day, representing a 24-hour period beginning at midnight. In computations of time, this means every day on the calendar, including weekends and holidays, unless the law specifically states "business days".
Combining livable space to the new Interior Livable Space definition:
oK. “Interior livable space” shall mean a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation.
Livable space includes bedrooms, bathrooms, kitchens, laundry rooms, closets, and interior stairs.
Staff’s Comments: SB 543 incorporates the use of “interior livable space” in regulating the size of ADUs. Therefore, interior livable space has been added as a definition to review and apply the code consistently with State laws. Business Days and Days (calendar days) have been added to the definition section as several California Gov.
Codes reference a limit on ADU review using these terms. These definitions were added in order to ensure staff reviews of ADUs are consistent with State laws.
AMENDMENTS TO SECTION 17.78.050 – PERMIT APPLICATION FOR AN
ACCESSORY DWELLING UNIT
Changes to this section include:
Removal of courtesy neighbor notification reports requirements. Refer submittal requirements to the existing Foster City ADU Checklist.
Staff’s Comments: Staff has revised requirements for the Permit Application submittal for a complete submittal to align with existing practice. An interdepartmental Accessory Dwelling Unit (ADU) Checklist was created and available on the Foster City ADU Webpage to provide a clear list of required documents an owner, applicant, or designer would need to submit a complete application.
These changes do not stem from the new ADU Bills mentioned above and are only staff recommended revisions to align submittal requirements with existing practice to streamline submittal and review for staff and applicants. Removing the courtesy neighbor notification requirement would make the ADU review consistent with the building permit review process and aims to reduce the Incompleteness Review timeframe while providing clear guidance to applicants.
AMENDMENTS TO SECTION 17.78.060.A.3.c – STANDARDS APPLICABLE TO
SINGLE-FAMILY RESIDENCE DISTRICTS
Changes to this section include:
Clarified Option 3.c can be an attached or detached ADU.
Staff Comments: This change did not stem from the new ADUs bills but is recommended as an administrative clarification for applicants’ use and staff.
AMENDMENTS TO SECTION 17.78.060.B – STANDARDS APPLICABLE TO SINGLE- FAMILY RESIDENCE DISTRICTS – JADUs REQUIREMENTS
Changes to this section include:
Added clarifications that JADUs only require owner occupancy if they do not have an independent sanitary facility in their unit.
Clarified JADUs entrance requirements.
Added Planning Commission’s suggested language to further clarify deed- restriction implementation per State Law.
Staff Comments: These code revisions address the JADU shared sanitation facilities per SB 543. Other revisions were made to provide language that is consistent with State laws and provide clarification to the applicant. As mentioned above, this section also include Planning Commission’s recommended language to further clarify that deed restrictions should only be implemented to the extent required by State law and can change should future successor code is amended from the State.
AMENDMENTS TO SECTION 17.78.060.C – STANDARDS APPLICABLE TO SINGLE- FAMILY RESIDENCE DISTRICTS – ATTACHED ADU REQUIREMENTS
Changes to this section include:
Clarifying maximum size of an ADU if the primary house to be 850 SF, consistent with State’s requirements, even if the 50% of the primary home’s size is less than that.
Clarified that State Exempt ADUs are not restricted in location placement.
Note: California Gov. Code Section 66323 creates four (4) categories of ADUs and JADUs that must be approved ministerially and are only subject to standards set forth in California Gov. Code Section 66323 and are known as State Exempt ADUs. These units do not have to comply with lot coverage, front setbacks, and design standards. However, these ADUs must comply with building code and health and safety requirements for dwellings.
Staff Comments: The current code requires the size of ADUs to be restricted to a maximum of 1,200 SF or 50% of the existing or proposed primary dwelling, whichever is less. However, for smaller homes such as those with only a 1,500 SF house, this 50% cap would allow only a 750 SF ADU, and therefore, is inconsistent with the requirement of other sections of the FCMC Chapter 17.78 and State law requiring jurisdictions to allow at least an 850 SF ADU. Therefore, this recommended change to Section
17.78.060.C.1.a was added as clarification that City shall allow a minimum of 850 SF for smaller single-family homes.
Furthermore, consistent with HCD guidelines and City’s legal council’s advice, State Exempt ADUs cannot be restricted from locating in the front yard. Accordingly, FCMC Section 17.78.060.C.2 has been updated to exempt State Exempt ADUs from the location requirement.
AMENDMENTS TO SECTION 17.78.060.D – STANDARDS APPLICABLE TO SINGLE- FAMILY RESIDENCE DISTRICTS – DETACHED ADU REQUIREMENTS
Changes to this section include:
Remove the 50% requirement from the size requirements for detached ADUs. Clarified that State Exempt ADUs are not restricted in location placement. Added clarification that 2 feet above the maximum requirement of 18 feet could be for roof pitch to align with the primary dwelling unit.
Staff Comments: The current Chapter 17.78 allows a size of 1,200 SF or 50% of the primary unit, whichever is less, for detached ADUs. Per legal counsel’s advice, the 50% limitation allowed by State laws is only for the attached ADUs. Since the State law does not reference this for attached ADUs, the proposed revision proposed to Section
17.78.060.D.1 would be consistent with HCDs requirements and interpretations.
Similar to attached ADUs, the State law does not allow local jurisdictions to limit the location of State Exempt ADUs. This has been noted in Section 17.78.060.D.2.
Staff revised language regarding the maximum height to provide a clear allowance of an additional 2’ in height to accommodate and match the roof pitch of the primary dwelling.
The context of this text amendment would not change how this requirement has been or will be applied.
AMENDMENTS TO SECTION 17.78.060.F – STANDARDS APPLICABLE TO SINGLE- FAMILY RESIDENCE DISTRICTS – ADDITIONAL REQUIREMENTS
Changes to this section include:
Moved exterior access language from Section 17.78.060.F Additional Requirements to Section 17.78.100 Other Provisions.
Minor clarification for interior space.
Staff Comments: Currently, State Exempt ADUs are exempt from this Section
17.78.060.F Additional Requirements. However, exterior entrances are required for all ADUs. Therefore, relocating this requirement to another part of the code such as Section
17.78.060.F would reduce misinterpreted during the implementation process.
AMENDMENTS TO SECTION 17.78.080.B – PARKING REQUIREMENTS FOR
ACCESSORY DWELLING UNITS
Changes to this section include:
Added clarification that State Exempt ADUs are exempt from parking requirements.
Staff Comments: Per California Gov. Code Section 66323, State Exempt ADUs are exempt from parking requirements and staff recommends this additional language for clarification.
AMENDMENTS TO SECTION 17.78.090 – PERMIT PROCESS
Changes to this section include:
Clarify the timeframe for review is 60 calendar days.
Clarify completeness review is 15 business days.
Revision to California Gov. Code Section 66317.
Staff’s Comments: A completeness review is local agency’s initial determination whether an application contains all required materials or in other words, is complete or not. Staff recommends revisions to the permit process language to provide clarification and aims to be consistent with California Gov. Code Section 66317. This would provide clear and transparent guidance to an applicant for the review timeline and expectations for both completeness and full review of an ADU project.
AMENDMENTS TO SECTION 17.78.100 – OTHER PROVISIONS
Changes to this section include:
Clarify the size limitation of ADUs are based on interior living space. Moved exterior access language from 17.78.060.F Additional Requirements to
17.78.100 Other Provisions and remove “JADUs”.
Staff’s Comments: The recommended changes to Section 17.78.100.L would provide clarification on how staff and the applicant would determine the size limitations of the proposed ADUs (i.e. interior living space), consistent with SB 543.
As mentioned above, the provision for exterior entrance requirement is better located in this section. Removal of the word “JADUs” is a clerical clarification as ADUs encompasses JADUs as well.
AMENDMENTS TO ADD NEW SECTION 17.78.110 – APPEAL
Changes to this section include:
Add a new section for an Appeal procedure for applicants who are not satisfied with ADU permit decision from the Building Official and making Planning Commission the hearing body.
Staff’s Comments: SB 543 required an appeal process to give the applicant the ability to appeal a permit application that has been deemed incomplete or has been denied. Staff recommends adding this new Section 17.78.110 Appeal to satisfy this new State requirement. The proposed appeal language would be consistent with the Chapter 15 – Building appeals. Additional language was added to ensure the timeline of appeals would be constant with SB 543.
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 California Gov. 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 staff time spent on the preparation of the Ordinance.
CITY COUNCIL VISION, MISSION, AND VALUE/PRIORITY AREA
Smart Planning, Development, and the Local Economy
ATTACHMENTS:
Attachment 1 – Ordinance
Attachment 1a – Exhibit A
Attachment 2 – Planning Commission Resolution P-11-26