San Francisco, CA Accessory Structures: ADU Rules (2026)

Two parallel pathways exist for ADU approval in San Francisco. The State Program offers streamlined ministerial review with a 60-day decision timeline and waives subjective design requirements, but limits compliance flexibility on certain Planning Code standards. The Local Program (under Planning Code Sec. 207 and 209) permits unlimited ADUs on some multi-family lots and provides waivers from specific code requirements for existing buildings; however, units approved under the Local Program typically fall under San Francisco rent control. California Government Code Sec. 65852.2 preempts local ordinances that would otherwise block ADU permits, requiring cities to approve compliant applications ministerially without discretionary review or public hearing. Owner-occupancy cannot be required for ADUs permitted between January 1, 2020 and January 1, 2025 under state law. Junior ADUs are conversions of existing space within a single-family home, capped at 500 square feet. ADUs in San Francisco may not be rented for periods less than 30 days (no STR use). Detached ADUs meeting specific criteria may be eligible for separate sale under recent state law amendments, but most ADUs cannot be sold apart from the main dwelling. Existing housing services such as garages or storage cannot be removed without justification when converting space to an ADU. Applicants should use the SF Property Information Map to confirm zoning before filing.