San Francisco has embraced ADUs as a key housing solution, with one of the most progressive ADU programs in the state. The city offers expedited review, fee waivers, and pre-approved plans to encourage ADU development.
Zoning & Size Requirements
| Allowed Zones | RH-1, RH-2, RH-3, RM, RTO zones and most residential districts |
| Max Size (Detached) | 1,200 sq ft |
| Max Size (Attached) | 1,200 sq ft or 50% of primary dwelling |
| Max Size (JADU) | 500 sq ft |
| Max Height | 25 ft for detached ADUs |
| Max Units | 1 ADU + 1 JADU per lot |
Setback Requirements
| Rear Setback | 4 ft minimum |
| Side Setback | 4 ft minimum |
| Front Setback | Must meet zone's front setback requirement |
| Parking Required | No parking required |
| Owner Occupancy | Not required |
| Min Lot Size | No minimum lot size |
Permit Process & Fees
| Approval Process | Ministerial (no discretionary review or public hearing) |
| Review Timeline | 60-day review period (state-mandated) |
| Permit Fees | $5,000-$20,000 depending on scope |
| Impact Fees | Waived for units under 750 sq ft |
| Plan Check | Expedited plan check available |
| Pre-Approved Plans | Yes — SF has pre-approved ADU plan sets |
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Construction Costs
| Average Build Cost | $200,000-$450,000 |
| Cost per Sq Ft | $300-$500 |
| Garage Conversion | $120,000-$250,000 |
| Prefab ADU (Installed) | $150,000-$350,000 (installed) |
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders in minutes.
Compare ADU Financing Options →Rental Income Potential
| Avg Rent (1 Bedroom) | $2,200-$3,200/mo |
| Avg Rent (2 Bedroom) | $2,800-$4,000/mo |
| Short-Term Rental | Heavily regulated; 90-day annual cap for unhosted |
| Est. Annual ROI | 5-8% annual return |
Explore Prefab ADU Options
Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half. Compare top prefab manufacturers.
Compare Prefab ADUs →Recent Law Changes
What's Changed Recently
- SB 1211 (Jan 2025): Multifamily ADU expansion
- AB 1033 (2024): Potential for separate ADU sales
- City streamlined ADU permit process (2024)
- New pre-approved plan sets added (2024)
Tips for Building an ADU in San Francisco
- SF's high rents make ADUs particularly profitable despite higher build costs
- Check historic district restrictions before planning your ADU
- Garage conversions are popular in SF due to limited lot space
- Consider a JADU if you want to minimize construction costs
Frequently Asked Questions
Can I build an ADU in San Francisco?
Yes. ADUs are allowed in RH-1, RH-2, RH-3, RM, RTO zones and most residential districts in San Francisco. The maximum size for a detached ADU is 1,200 sq ft. No owner-occupancy is required.
How much does an ADU cost in San Francisco?
ADU construction in San Francisco typically costs $200,000-$450,000. Garage conversions run $120,000-$250,000, and prefab ADUs cost $150,000-$350,000 (installed).
How much can I rent an ADU for in San Francisco?
Average ADU rents in San Francisco are $2,200-$3,200/mo for a 1-bedroom and $2,800-$4,000/mo for a 2-bedroom unit.
Do I need parking for an ADU in San Francisco?
No parking required. Check with San Francisco planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in San Francisco?
The permit review timeline in San Francisco is 60-day review period (state-mandated). Fees range from $5,000-$20,000 depending on scope.
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