Oakland sorts ADUs on single-family lots into a JADU, a Category One ADU (conversion of existing space, expansion only up to 150 sq ft for an entry) and a Category Two ADU (new detached or attached construction). A lot can have one of each, up to three.[1]
California cities can set their own ADU rules, but never stricter than state law. Grey lines show the state floor from the HCD ADU Handbook.
| Size limits | No city-specific figure verified. The state minimum below applies; confirm local details with the city. State law: a city's maximum size must allow at least 850 sq ft, or 1,000 sq ft for more than one bedroom, and local rules cannot block an 800 sq ft ADU with 4 ft side and rear setbacks (Gov. Code 66321).[2] |
|---|---|
| Height | No city-specific figure verified. The state minimum below applies; confirm local details with the city. State law: detached ADUs get at least 16 ft; 18 ft within a half mile walk of a major transit stop or high-quality transit corridor (plus 2 ft to match roof pitch) or on a lot with a multistory multifamily building; attached ADUs up to 25 ft or the main home's limit if lower (Gov. Code 66321).[2] |
| Setbacks | No city-specific figure verified. The state minimum below applies; confirm local details with the city. State law: side and rear setbacks can be no more than 4 ft for new ADUs; converted existing space needs no new setback (Gov. Code 66314, 66323).[2] |
| Parking | No city-specific figure verified. The state minimum below applies; confirm local details with the city. State law: at most 1 space per ADU or per bedroom, whichever is less, and none within a half mile walk of public transit, in a historic district, within one block of a car share, or for ADUs inside the house (Gov. Code 66314, 66322).[2] |
| Owner occupancy | A JADU (up to 500 sq ft) requires proof of ownership and owner occupancy in the JADU or the main home.[1] State law: no owner occupancy requirement for ADUs (Gov. Code 66315). A JADU requires the owner to live on site if it shares a bathroom with the main home (Gov. Code 66333).[2] |
| Permit steps and timeline | Every ADU needs a Planning permit and then a Building permit, applied for through the Online Permit Center. Building permits also need an approved recycling plan, and detached ADUs need a sewer lateral permit. Pre-approved studio, 1 and 2 bedroom plans are available.[1] State law: the city must approve or deny a complete application within 60 days when there is an existing home on the lot (Gov. Code 66317).[2] |
| Fees | No city-specific figure verified. The state minimum below applies; confirm local details with the city. State law: no impact fees on ADUs of 750 sq ft or less; above that, impact fees must be proportional to the size of the main home. Plan check, permit and school fees can still apply.[2] |
Also worth knowing: Rentals: ADUs and JADUs cannot be rented for less than 30 days, and renting one requires a city business license.[1]
We connect you with builders who serve your area. Free, no obligation.
Sources
Every fact above links to an official city or state page. Rules change; check the source before you build.
- [1] City of Oakland: ADU with Single Family Home checked Oct 2026
- [2] HCD ADU Handbook (March 2026) checked Oct 2026