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San Francisco County, California
Find out if your San Francisco property qualifies for an Accessory Dwelling Unit. Under California state law (AB 68, AB 881), San Francisco must approve ADUs that meet state standards — no discretionary review, no public hearings. Enter your lot size and home details to see every ADU option available to you, including detached ADUs, Junior ADUs, garage conversions, and multi-unit scenarios under SB 1211.
Provide your lot size, primary home square footage, and whether you have a garage. These determine which ADU types are available to you under California law.
Our rules engine evaluates your property against AB 68, AB 881, AB 897, SB 1211, and AB 1033 — the key California ADU laws that override local zoning restrictions.
Get a breakdown of every ADU type you qualify for — detached, JADU, garage conversion, or multiple units — with maximum sizes, setbacks, and parking requirements.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a single-family or multi-family residential lot. California has some of the most permissive ADU laws in the country — in most cases, your city cannot deny an ADU that meets state standards.
There are four main types of ADUs in California:
ADU construction costs in California typically range from $150,000–$350,000 for new construction, depending on size, finishes, and location. Garage conversions are cheaper ($80,000–$150,000) since the shell already exists. Prefab ADUs can start around $100,000–$200,000 plus site work. Permit fees vary by city but typically run $5,000–$15,000.
If your ADU meets California state standards (size, setbacks, height), your city must approve it ministerially — meaning no discretionary review, no public hearings, no CEQA review. Cities can only deny ADUs that don't meet objective standards. If your city is stalling, you can file a complaint with the California Department of Housing and Community Development (HCD).
For standard ADUs (detached or attached), no — California law prohibits cities from requiring owner occupancy. For Junior ADUs (JADUs), owner occupancy IS required — either in the primary home or the JADU itself. This distinction matters if you're an investor or planning to rent both units.
California law requires cities to approve or deny ADU permits within 60 days of a complete application. In practice, getting to a "complete" application can take time — plan check corrections, utility clearances, and structural review often add 2–4 months. Total timeline from design to move-in is typically 8–14 months.
Yes, but only on the added value. Under Proposition 13, your existing home's assessed value doesn't change. The ADU itself will be assessed at its construction cost, adding roughly $1,000–$3,500/year in property taxes depending on size. Rental income from the ADU typically far exceeds the tax increase.
Yes. California law explicitly allows one ADU plus one JADU on any single-family lot. This means you can have your primary home, a detached 1,200 sqft ADU in the backyard, AND a 500 sqft JADU converted from a bedroom — three units total on a single-family lot.