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Report regarding proposed 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 amendments are categorically exempt from the California Environmental Quality Act (CEQA). (Stephanie Skangos, Senior Planner)
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MOTION FOR THE COMMISSION TO ADOPT STAFF RECOMMENDATION:
(1) Move to adopt the Resolution determining the proposed updates to ADU regulations are exempt from CEQA and recommending that the City Council adopt an Ordinance amending Title 20 of the South San Francisco Municipal Code.
RECOMMENDATION
Recommendation
Staff recommends that the Planning Commission conduct a public hearing and take the following action:
1. Adopt the attached Resolution determining that the proposed Zoning Ordinance amendments do not require additional environmental review and is exempt from the California Environmental Quality Act (CEQA) and recommending that the City Council adopt 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 ADU Ordinance to ensure compliance with the most current state law requirements is formalized and reviewed by HCD; the proposed updates to the Ordinance will not change the City’s practices.
A summary of the changes is included below, and staff has prepared a draft ordinance that is attached to the associated Resolution as Exhibit A.
• 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 has been changed from: one (1) ADU of any type (attached, detached or converted) AND one (1) JADU to: one (1) detached ADU; AND either one (1) converted ADU (within the existing space of the home or an accessory structure) or one (1) attached ADU, but not both; AND one (1) JADU. This is an interpretation from HCD of State law and referenced in their HCD Accessory Dwelling Unit Handbook, updated March 2026. As such, the Planning Division and City Attorney are recommending that this interpretation be formalized in the City’s ADU Ordinance. This change will increase the total number of allowed ADUs, including JADUs, on a single-unit lot from two (2) to three (3). 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. However, any single-unit lot that has completed a lot split under SB 9 would be limited to one (1) ADU or JADU only if there is one (1) primary unit on the lot; if there are two (2) primary units on the lot, an ADU or JADU would not be allowed.
• For a multiple-unit lot with an existing multiple-unit dwelling, the number of allowed detached ADUs has increased from two (2) to up to eight (8) detached ADUs, not to exceed the number of existing residential units on the lot. This is in addition to an existing requirement that allows for 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. For a multiple-unit lot with a proposed multiple-unit dwelling, the number of detached ADUs allowed remains two (2), and no converted ADUs are allowed.
• 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, which states 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.
CONCLUSION
Staff recommends that the Planning Commission conduct a public hearing and adopt the attached Resolution determining that the proposed Zoning Ordinance update does not require further environmental review and is exempt from CEQA, and recommending that the City Council adopt an Ordinance updating regulations pertaining to accessory dwelling units to Title 20 (“Zoning”) of the South San Francisco Municipal Code.
Exhibits to Associated Resolution (26-1761)
A. Draft Ordinance Implementing Zoning Text Amendments