San Francisco at a Glance
873.9K
Population
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Parcels
—
Median Lot
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Median Assessed
Building Code Requirements
These are the key dimensions and limits that govern what you can build in San Francisco. Every project — whether it's a new home, ADU, remodel, or addition — must comply with these requirements.
40'
Max Height
0'
Front Setback
0'
Side Setback
15'
Rear Setback
75%
Lot Coverage
0
Parking / Unit
Values shown are for standard single-family residential zones. Multi-family zones, commercial zones, and overlay districts have different requirements. View all San Francisco zone tables →
What You Can Build in San Francisco
California state law overrides many local zoning restrictions for housing development. Here's what's available to property owners in San Francisco, regardless of what local ordinances say.
Accessory Dwelling Unit (ADU)
State LawBuild a second home on your lot — detached, attached, or converted from a garage. California law (AB 68 / AB 881) guarantees ADU rights for all residential properties. No minimum lot size. Cities must approve ministerially within 60 days.
Junior ADU (JADU)
State LawConvert space within your existing home into a separate rental unit — up to 500 sf. Can be built in addition to an ADU, giving you two income-producing units on one lot. Owner occupancy required for either the JADU or primary home.
SB 9 — Duplex + Lot Split
State LawSplit your lot in two and build a duplex on each half — up to four units total on what was a single-family lot. No public hearing, no discretionary review, no environmental review (CEQA exempt). Ministerial approval required.
SB 1211 — Streamlined ADU
State LawEffective January 2025: two-story ADUs up to 1,000 sf are pre-approved statewide. No local design review, no discretionary process. Cities must approve compliant plans within 30 days.
AB 1033 — ADU Condo Conversion
Opt-InIf your city has adopted a local ordinance, ADUs can be sold as separate condominiums — independent from the primary home. This unlocks a new path to homeownership and lets ADU builders recoup their investment through sale rather than rental income only.
Housing News in San Francisco
Contributor: Rent algorithms aren't the issue. California just needs more housing
Mar 26 · LA Times California
Scott Wiener passed laws that made it easier to build in California. Can he do the same in Congress?
Mar 23 · CalMatters Housing
Sebastopol City Council approves ADU condo conversions, but that's just the beginning - sebastopoltimes.com
Jan 09 · sebastopoltimes.com
Samara to add ADUs to five multifamily properties in the Bay Area - HousingWire
Dec 05 · housingwire.com
Building Permits Filed For ADU at 160 Chilton Avenue in Glen Park, San Francisco - San Francisco YIMBY
Nov 30 · sfyimby.com
San Jose becomes first California city to allow sale of ADUs as condos - San Francisco Chronicle
Aug 15 · sfchronicle.com
Frequently Asked Questions
Can I build an ADU in San Francisco? +
Yes. California state law (AB 68/AB 881) allows at least one ADU on any residential lot in San Francisco. ADUs up to 800 sf are approved ministerially within 60 days, regardless of local zoning.
What is SB 9 and does it apply in San Francisco? +
SB 9 (California Housing Opportunity and More Efficiency Act) allows duplexes and lot splits on single-family lots statewide. In San Francisco, this means you can potentially build up to 4 units on what was a single-family lot — no public hearing required.
What are the setback requirements in San Francisco? +
Setback requirements in San Francisco vary by zone. Use LotCheck to check your specific property's setback requirements against San Francisco County's zoning code. For ADUs, California state law allows reduced setbacks of 4 feet for rear and side yards.
How much does an ADU cost to build in San Francisco County? +
ADU construction in San Francisco County typically ranges from $150,000 to $400,000 depending on size, finishes, and whether it's a conversion or new construction. Garage conversions tend to be the most affordable option.