Are ADUs allowed in San Francisco?

Yes. San Francisco permits Accessory Dwelling Units citywide through two paths: the California state ministerial program (Gov. Code § 66314) and San Francisco’s own local program (Planning Code § 207(c)(4)), which allows more flexibility in exchange for conditions such as Rent Ordinance coverage.

Does the SF Rent Ordinance apply to ADUs?

Often, yes. ADUs approved through San Francisco’s local program are typically made subject to the Rent Ordinance, including just-cause eviction protections, as a condition of approval. State-program ADUs are generally exempt from rent-increase limits under Costa-Hawkins but may still carry just-cause protections. Confirm a specific unit’s status with the San Francisco Rent Board (415-252-4600).

Can I use a San Francisco ADU as a short-term rental?

Generally no. ADUs are intended for long-term housing; San Francisco prohibits short-term rental of most ADUs, and the city separately regulates short-term rentals through the Office of Short-Term Rentals.

How do I check that a San Francisco ADU is legal?

Look up the address on the Department of Building Inspection permit tracking system and confirm the ADU has a finaled building permit. A-du does not list San Francisco rentals today. In the Bay Area, A-du helps owners build detached ADUs from Build Marketplace designs, and a licensed architect can review an existing unit built without a permit for legalization.

Can I legalize an ADU that was built without a permit in San Francisco?

There is a city path for it. San Francisco’s Dwelling Unit Legalization Program (Ordinance 43-14) covers units that existed before January 1, 2013. It starts with a free DBI screening form filed by a California-licensed architect, engineer or contractor, followed by a Planning Project Application. One unit per lot can be legalized, the Building Code applies in full, and certain no-fault evictions can rule a unit out. Units built before 2020 may also have a path under the state’s AB 2533.

ADU Rentals & Regulations in San Francisco

An ADU in San Francisco is an Accessory Dwelling Unit permitted under California state law or San Francisco's local ADU program, on a residential lot in the City and County of San Francisco.

San Francisco is a consolidated city-county: one permitting authority (DBI, with Planning review) covers the entire market.

Two ways to permit an ADU in San Francisco

San Francisco runs a dual-track ADU program. The state program (Gov. Code § 66314) is ministerial: 4-foot rear and side setbacks, up to 16 feet in height for a detached unit, and no discretionary review. The local program (Planning Code § 207(c)(4)) allows larger units and waivers of certain Planning Code standards. The trade-off is that units approved this way are typically made subject to the SF Rent Ordinance as a condition of approval. Many garage, basement, and rear-yard conversions go through the local program.

Free city ADU plans in the Bay Area

San Francisco does not offer free city-drawn ADU plans, but three Bay Area cities do, for detached units on their own lots: Oakland (a studio, a 1-bedroom and a 2-bedroom), San Ramon (three 1-bedroom plans in three styles) and Los Altos (three plans in three styles). Each plan is pre-approved only in the city that published it. You can open all of them on the Build Marketplace.

Renting an ADU in San Francisco

A permitted, finaled ADU can be rented as long-term housing, and San Francisco's rental rules are among the most protective in the country: the Rent Ordinance (Administrative Code Chapter 37) limits rent increases and requires just cause for eviction on covered units, Chapter 49 requires annual interest payments on security deposits, and the Fair Chance Ordinance (Police Code Article 49) restricts criminal-history screening for covered housing.

Building an ADU in San Francisco

Permitting runs through the Department of Building Inspection with Planning review. Budget for permit-issuance and plan-review fees based on construction valuation using the free San Francisco permit-fee calculator, and check whether an ADU fits your lot with the A-du test-fit tool on any Build Marketplace design.

Legalizing an existing unit in San Francisco

San Francisco has its own path for units built without a permit, the Dwelling Unit Legalization Program under Ordinance 43-14. According to DBI Information Sheet G-17 and SF Planning’s legalization FAQ, the owner shows the unit existed before January 1, 2013, and a California-licensed architect, engineer or contractor files a free DBI screening form. Planning then reviews a Project Application before the building permit. One unit per lot can be legalized. Planning waives density, rear yard, open space, exposure and parking standards, but the Building Code applies in full, and certain no-fault evictions can rule a unit out. A unit already under the Rent Ordinance stays under it. Units built before 2020 may also have a path under the state’s AB 2533, which other Bay Area cities apply through their own process.

If you have a unit like this anywhere in the Bay Area, you can ask a licensed architect to review it. The request form is written around Los Angeles but takes any California address. The review is performed by Chris Koss, AIA, an independent licensed architect, under a separate written agreement with you, not by A-du, and whether a unit qualifies is for the city to decide.

Building a detached ADU or legalizing an existing one? Browse ADU designs on A-du, ask for a legalization review, or estimate your permit with the San Francisco permit fee calculator.

Frequently asked questions

Are ADUs allowed in San Francisco?: Yes. San Francisco permits Accessory Dwelling Units citywide through two paths: the California state ministerial program (Gov. Code § 66314) and San Francisco’s own local program (Planning Code § 207(c)(4)), which allows more flexibility in exchange for conditions such as Rent Ordinance coverage.
Does the SF Rent Ordinance apply to ADUs?: Often, yes. ADUs approved through San Francisco’s local program are typically made subject to the Rent Ordinance, including just-cause eviction protections, as a condition of approval. State-program ADUs are generally exempt from rent-increase limits under Costa-Hawkins but may still carry just-cause protections. Confirm a specific unit’s status with the San Francisco Rent Board (415-252-4600).
Can I use a San Francisco ADU as a short-term rental?: Generally no. ADUs are intended for long-term housing; San Francisco prohibits short-term rental of most ADUs, and the city separately regulates short-term rentals through the Office of Short-Term Rentals.
How do I check that a San Francisco ADU is legal?: Look up the address on the Department of Building Inspection permit tracking system and confirm the ADU has a finaled building permit. A-du does not list San Francisco rentals today. In the Bay Area, A-du helps owners build detached ADUs from Build Marketplace designs, and a licensed architect can review an existing unit built without a permit for legalization.
Can I legalize an ADU that was built without a permit in San Francisco?: There is a city path for it. San Francisco’s Dwelling Unit Legalization Program (Ordinance 43-14) covers units that existed before January 1, 2013. It starts with a free DBI screening form filed by a California-licensed architect, engineer or contractor, followed by a Planning Project Application. One unit per lot can be legalized, the Building Code applies in full, and certain no-fault evictions can rule a unit out. Units built before 2020 may also have a path under the state’s AB 2533.

This guide is general information, not legal advice. San Francisco planning, building, and rental rules change; confirm current requirements with SF Planning, the Department of Building Inspection, and the San Francisco Rent Board.