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Report regarding consideration of an Ordinance adopting Zoning Text Amendments to Title 20 of the South San Francisco Municipal Code to update regulations pertaining to accessory dwelling units to comply with California state law, and determination that the proposed zoning text amendments are statutorily exempt from the California Environmental Quality Act (CEQA). (Stephanie Skangos, Senior Planner)
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RECOMMENDATION
Recommendation
Staff recommends that the City Council conduct a public hearing, follow the recommendation of the Planning Commission, and take the following action:
1. Determine that the proposed Zoning Ordinance amendments do not require additional environmental review and is exempt from the California Environmental Quality Act (CEQA); and
2. Waive reading and introduce an Ordinance updating regulations pertaining to accessory dwelling units in Title 20 (“Zoning”) of the South San Francisco Municipal Code.
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BACKGROUND/DISCUSSION
The State continues to adopt new legislation on accessory dwelling units (ADUs) annually to help streamline the creation of ADUs as a housing opportunity. Local jurisdictions are required to incorporate these mandated requirements into their ADU Ordinances and submit them to the California Department of Housing and Community Development (HCD) for review within 60 days of adoption. Any local ADU Ordinance that is not reviewed by HCD and issued findings notifying the jurisdiction if their ordinance complies with State standards can be deemed null and void.
While the City has annually updated ADU review and approval practices in accordance with State law, the last update to the City’s ADU Ordinance to formalize the requirements was completed in June 2024. As such, the Planning Division and the City Attorney have completed a thorough evaluation of the City’s ADU Ordinance and is recommending updates to the Ordinance to ensure it will comply with the most current state law requirements that have become effective since June 2024, which include Assembly Bill (AB) 462, AB 1154, Senate Bill (SB) 9, SB 543, and SB 1211; City practices in ADU review and approval will also be updated accordingly.
A summary of the changes is included below.
• Maximum Number of Units Allowed:
• For a single-unit lot with an existing or proposed single-unit dwelling, the number and type of allowed ADUs shall be:
§ One (1) detached ADU; AND
§ One (1) converted ADU (within the existing space of the home or an accessory structure); AND
§ One (1) JADU; AND
§ One (1) attached, detached OR converted ADU (not exempt from local development standards)
This change will increase the total number of allowed ADUs, including JADUs, on a single-unit lot from two (2) to four (4).
Figure 1: Maximum Allowed ADUs on a Single-Unit Lot
Staff would like to clarify that this allowance would apply to all single-unit lots, including those that have constructed two (2) primary units allowed under State Bill (SB) 9. Therefore, a single-unit lot that contains two (2) primary units under SB 9 would also be able to have the same number and type of ADUs listed above, which would result in a total of six (6) residential units on the lot.
Figure 2: Maximum Allowed ADUs on a Single-Unit Lot with Two Primary Units under SB 9
Any single-unit lot that has completed a lot split under SB 9 would be limited to the following:
• One (1) ADU or JADU only if there is one (1) primary unit on the lot, which would result in two (2) total residential units on the split lot.
• If there are two (2) primary units on the lot, an ADU or JADU would not be allowed, maintaining the limit of two (2) total residential units on the split lot.
Figure 3: Maximum Allowed ADUs on a Single-Unit Lot with a Lot Split Under SB 9
• For a multiple-unit lot with an existing multiple-unit dwelling, the number and type of allowed ADUs shall be:
§ Up to eight (8) detached ADUs, not to exceed the number of existing residential units on the lot; AND
§ Converted ADUs up to 25% of the existing number of units or one, whichever is greater, within portions of an existing structure that are not used as livable space; AND
§ One (1) attached, detached OR converted ADU (not exempt from local development standards)
• For a multiple-unit lot with a proposed multiple-unit dwelling, the number and type of allowed ADUs shall be:
§ Up to two (2) detached ADUs; AND
§ One (1) attached, detached OR converted ADU (not exempt from local development standards)
This increases the total allowed ADUs on a multiple-unit lot by one (1) additional ADU, attached, detached, or converted, resulting in various totals based on the number of existing or proposed residential units.
• Maximum Floor Area: The maximum square footage for an ADU and JADU has been clarified to refer to interior “livable space,” which is defined under California Government Code Section 66313 as “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. Exterior walls or attic areas with low ceilings are not included in maximum square footage.
• Parking Replacement: Replacement parking is still not required when an ADU or JADU replaces required parking for the primary residence, and state law has included two new requirements in relation to the demolition of existing garages for an ADU or JADU:
• A demolition permit for a detached garage that is to be replaced with an ADU or JADU shall be reviewed with the application for the ADU or JADU and issued at the same time; and
• The applicant shall not be required to provide written notice or post a placard for the demolition unless the property is located within an architecturally and historically significant historic district.
• Occupancy: Owner occupancy requirements are no longer permitted for JADUs that have separate sanitation facilities from the primary dwelling; however, for a JADU with shared sanitation facilities with the primary dwelling, the owner must still occupy the primary dwelling or JADU. The majority of JADUs applied for and approved by the City have historically contained separate sanitation facilities from the primary dwelling; thus, most new JADUs will not be subject to the owner occupancy requirements.
• Fire Sprinklers: State law now includes new requirements regarding fire sprinklers in ADUs: An ADU shall not be required to provide fire sprinklers if they are not required for the primary dwelling; additionally, the construction of an ADU shall not trigger a requirement for fire sprinklers to be installed in the existing primary dwelling. In practice, this new requirement can conflict with guidance from the Office of the State Fire Marshal (OSFM), which states that all newly constructed ADUs are required to comply with the standards for fire protection and lists automatic sprinkler systems as a method for complying, if there are no other options for compliance. Further guidance on this issue is being sought at this time.
GENERAL PLAN CONSISTENCY ANALYSIS
The proposed Zoning Text Amendment is consistent with the City’s overall vision for providing a diversity of housing types responsive to household size, income, and age needs. Specifically, it will reinforce the below General Plan policies:
• Policy LU-3.1: Create affordable and workforce housing.
• Policy LU-3.3: Encourage diversity of housing types and sizes.
• Policy LU-3.4: Facilitate multi-generational housing.
• Policy LU-4.2: Encourage small-scale residential infill development.
None of the new or revised requirements for accessory dwelling units and junior accessory dwelling units will conflict with or impede achievement of any of the goals, policies, or land use designations established in the General Plan.
ENVIRONMENTAL REVIEW
The modifications to regulations pertaining to ADUs are statutorily exempt from CEQA pursuant to Section 21080.17 of the Public Resources Code and CEQA Guidelines Section 15282.1(h), which state that local ordinances that are aimed at creating ADUs or JADUs are exempt from CEQA. Therefore, no further environmental review is required at this time.
PLANNING COMMISSION ACTION
The Planning Commission considered the proposed zoning text amendments to the Zoning Ordinance during a public hearing held on May 21, 2026, and unanimously voted to recommend approval of the proposed Zoning Ordinance amendments to City Council. Prior to proceeding to City Council for review of the proposed changes, staff became aware of an updated interpretation of State law by HCD regarding the total number of ADUs allowed on single- and multiple-unit lots outlined in HCD’s Accessory Dwelling Unit Handbook, updated March 2026. Staff returned to the Planning Commission on July 16, 2026 with the updated proposed amendments that included HCD’s interpretation to formalize in the City’s ADU Ordinance and ensure continued consistency with State law. The Planning Commission again unanimously voted to recommend approval to City Council. The Planning Commission resolution recommending approval is included as Attachment 1 to this staff report.
It should be noted that prior to the Planning Commission’s respective meetings on May 21, 2026, and July 16, 2026, the City received comment letters from the California Housing Defense Fund (CalHDF). Both of the comment letters stated that the proposed amendments to the ADU Ordinance - specifically, to Section 20.350.003(J) - impermissibly requires a deed restriction for ADUs, in violation of Gov. Code section 663223, and cited to a page in the HCD ADU Handbook in support of the claim that deed restrictions are unlawful. The City published a response to this comment prior to each respective meeting, stating that the aforementioned deed restriction enforces state law and is therefore not in violation of Gov. Code section 66323. Specifically, the deed restriction required by Section 20.350.003(J) covers (1) no separate sale of ADUs unless authorized by state law; (2) no short-term rentals for less than 31 days; (3) compliance with maximum size requirements which are set forth under Gov. Code Sections 66314(d)(4) and (5), incorporated into this chapter; and (4) these restrictions run with the land. In reviewing the HCD Handbook, staff noted in the comment letter that the prohibition against deed restrictions referenced by CalHDF is specifically referring to “affordable housing deed restrictions,” which the City does not impose. Nor does the City impose additional standards other than statutory requirements. Property owners must comply with these state law requirements in the deed restriction. Therefore, the deed restriction requirement is consistent with state law. Staff would like to flag this issue for the Council ahead of time, in case CalHDF submits another similar comment letter prior to the public hearing for this proposed Zoning Ordinance update.
FISCAL IMPACT
There is no immediate fiscal impact to the City with adoption of the proposed zoning text amendments to the Zoning Ordinance.
RELATIONSHIP TO CITY COUNCIL PRIORITIES ACTION PLAN
The proposed ADU Ordinance update directly supports the City Council major focus area of “Housing and Supportive Services”, as it will further streamline the creation of ADUs as a housing opportunity and add to the diversity of housing types available in response to household size, income, and age needs in the City.
CONCLUSION
Staff recommends that the City Council conduct a public hearing, follow the recommendation of the Planning Commission, and determine that the proposed Zoning Ordinance update does not require further environmental review and is exempt from CEQA, and introduce an Ordinance updating regulations pertaining to accessory dwelling units to Title 20 (“Zoning”) of the South San Francisco Municipal Code.
Attachments
1. Planning Commission Resolution No. 13-2026
2. Staff Presentation
Associated Documents
1. Zoning Text Amendment Ordinance (26-1997)
a. Exhibit A - Amendments to Title 20 of the South San Francisco Municipal Code