ADU Regulations in San Francisco, California
San Francisco County · CA · Pop. 875,000
Max ADU Size
1,200
sq ft detached
Rear Setback
45 ft from rear property line in RH zones; 25 ft in RM zones
Permit Timeline
60–120 days
Build Cost
$250,000 – $700,000
Zoning
Allowed ADU Types
San Francisco's ADU program strongly encourages conversion of existing spaces (garages, basements) over new construction due to density and lot constraints
Source: City of San Francisco — ADU Program · SF Planning Code Section 207.1 & 207.2
Dimensions
Size & Setback Requirements
Detached
1,200
sq ft max
JADU
500
sq ft max
Attached
Up to 1,200 sq ft or 50% of primary, whichever is less
Setbacks
front
Same as primary dwelling; varies by zoning district
side
3 ft minimum (may be reduced for existing structures)
rear
45 ft from rear property line in RH zones; 25 ft in RM zones
Max height: Match existing structure height or 16 ft for detached
Lot coverage: Subject to rear yard requirements by zoning district
Rear yard requirements are more restrictive in SF than state minimums — check your specific zoning district. Basement and garage conversions often avoid these restrictions.
Permitting
Permit Process
Department
SF Department of Building Inspection (DBI) & SF Planning
Review Timeline
60–120 days; historic district properties may require additional Planning review
Permit Fees
$8,000 – $35,000
Impact Fees
Waived for ADUs 750 sq ft and under per state law
Required Documents
- ›Building permit application (DBI)
- ›Architectural drawings (stamped by licensed architect or engineer)
- ›Site plan and plot plan
- ›Floor plans showing all floors
- ›Sections and elevations
- ›Title 24 energy compliance
- ›Structural engineering drawings
- ›Soils report (if new foundation required)
San Francisco requires a licensed architect or engineer to stamp plans. Historic districts require Planning Department sign-off.
Visit SF Department of Building Inspection (DBI) & SF Planning →Infrastructure
Utilities & Requirements
Solar
Required
Parking
Not required
Separate Meter
Optional
Fire Sprinklers
See note
Existing tenants in a unit being converted to ADU have right-of-first-return protections under SF law. Consult with an attorney before converting occupied units.
Financials
ADU Costs in San Francisco
Typical Build Cost
$250,000 – $700,000
Cost per Sq Ft
$400 – $700
Monthly Rental
$2,500 – $6,500/mo
Property Value Added
Adds $300,000 – $600,000 to property value in SF market
Available Grants & Programs
- ★CalHFA ADU Grant Program (up to $40,000)
- ★SF Mayor's Office of Housing programs for affordable ADUs
San Francisco has the highest ADU construction costs in California due to union labor requirements, seismic requirements, and permit complexity. Garage conversions (basement or ground floor) are typically the most cost-effective path.
Use the free ADU Cost Calculator →Free Service
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San Francisco Quick Facts
- Max size1,200 sq ft
- Rear setback45 ft from rear property line in RH zones; 25 ft in RM zones
- Permit timeline60–120 days
- Build cost$250,000 – $700,000
- Rental income$2,500 – $6,500/mo
- Owner occupancyNot required
Official Source
City of San Francisco — ADU ProgramSF Planning Code Section 207.1 & 207.2
Last verified: March 14, 2026
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ADU rules change often.
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