ADU Rules in San Francisco, CA — 2026 Guide
Check if your San Francisco property qualifies for an ADU in 20 seconds
San Francisco ADU Rules at a Glance
San Francisco is considered ADU-friendly. Here are the key regulations.
- SF allows ADUs in all residential and mixed-use zones under state law.
- No minimum lot size for a detached ADU up to 800 sqft.
- Impact fees waived for ADUs under 750 sqft.
- Garage conversions are a popular ADU strategy — no replacement parking required.
What ReadyPermit Checks for San Francisco Properties
Enter any San Francisco address and get an instant ADU feasibility analysis covering:
Zoning Compliance
Verify your San Francisco lot is zoned for ADU construction under current CA and local rules.
Setbacks & Coverage
Check required setbacks, lot coverage limits, and height restrictions for your specific parcel.
ADU Size Limits
Calculate the maximum ADU square footage allowed based on your lot size and primary dwelling.
Permit Requirements
Understand what permits and approvals San Francisco requires before you can break ground.
Flood & Hazard Zones
Identify if your property falls in a flood zone, fire zone, or other hazard overlay.
Lot & Parcel Data
Pull parcel boundaries, lot dimensions, and existing structures from county records.
Check Your San Francisco Property Free
Enter your address below. In under 20 seconds you will know if your San Francisco lot qualifies for an ADU — no phone calls, no waiting.
No credit card required. Instant results.