ADU Rules in San Francisco County, California

We track 1 city in San Francisco County. Each city writes its own ADU ordinance on top of California law, so size limits, fees, and design rules differ from one city to the next.

Cities

Max Detached Size

1,000 sq ft

Build Costs From

$250,000

Pre-approved Plans

0 of 1 cities

San Francisco County Cities Compared

City	Max detached	Height	Permit fees	Build cost
San Francisco	1,000 sq ft	18 ft for detached ADUs under the State program, plus 2 ft to match the roof pitch of the main house	$8,000 – $35,000	$250,000 – $700,000

San Francisco ADU rules

San Francisco runs two ADU programs: the State program, with fast ministerial review, 4 ft side and rear setbacks and detached units up to 850 sq ft (studio or one-bedroom) or 1,000 sq ft (two or more bedrooms), and the Local program, which allows larger ADUs inside an existing building envelope but triggers city tenant protections. Most projects convert garages or ground floors. Plans must be stamped by a licensed architect or engineer.

Rules that apply in every California city are summarized in our California ADU law guide. See all California cities or compare every city side by side.