Accessory Structures in South San Francisco, CA (2026)
4 verified accessory structures rules for South San Francisco, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
South San Francisco allows ADUs per California state law (SSFMC Title 20). Detached ADUs up to 1,200 sq ft max; minimum 800 sq ft and 16 ft allowed by right. 4-ft setbacks. ADUs cannot be STRs.
South San Francisco ADU Rules
Some RestrictionsShed Rules
Small accessory structures (sheds) in South San Francisco must comply with SSFMC Title 20 setbacks. Sheds under 120 sq ft and under 8 feet generally do not require a building permit but must still meet zoning requirements.
South San Francisco Shed Rules
Some RestrictionsGarage Conversions
Garage conversions to ADUs are permitted in South San Francisco per California ADU law. Building permit required. No replacement parking needed when converting a garage to an ADU under state law.
South San Francisco Garage Conversion Rules
Some RestrictionsCarport Rules
South San Francisco Municipal Code Chapter 20.300 (Lot and Development Standards) and Chapter 20.330 (On-Site Parking and Loading) govern carports as accessory structures. Unlike many neighboring cities, SSFMC Section 20.330.004 expressly allows the required residential parking space to be 'within a carport or garage' — open carports are an acceptable form of required parking. Carports must comply with a minimum 5-foot setback for accessory structures, must be at least 6 feet from the main building, and accessory-building height is limited to an average of 12 feet between floor slab and ridge pole. Combined accessory-building footprint may not exceed 20 percent of the main building's footprint or 220 square feet, whichever is greater. A building permit is required.
South San Francisco Carport Rules
Some RestrictionsLooking for San Mateo County county-wide rules?
County ordinances apply to unincorporated areas and may supplement South San Francisco city rules.
Accessory Structures in San Mateo County →