Los Angeles regulates ADUs under its 2019 ADU Ordinance (Ordinance 186,481, LAMC 12.22 A.33) and also applies state ADU law. Owners can choose an Ordinance ADU or a State ADU, and the two have different limits.[1]
What is an ADU? An accessory dwelling unit is a small second home on the same lot as the main house: a backyard unit, garage conversion, attached addition or guest house with its own kitchen and bath.
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 | Ordinance detached ADU: up to 1,200 sq ft, unless lot floor area or coverage rules limit it further. State detached ADU option: 800 sq ft.[2] 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).[4] |
|---|---|
| Height | Ordinance ADU: max 2 stories (basements not counted) and the zoning height limit. State detached ADU: 16 ft, or 18 ft within a half mile of transit, plus 2 ft (20 ft total) if the roof pitch matches the main home.[2] 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).[4] |
| Setbacks | 4 ft side and rear for a new building or addition. None extra for an existing structure converted or rebuilt in the same place and size.[2] 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).[4] |
| Parking | Ordinance ADUs: see LAMC 12.22 A.33 (state exemptions such as transit proximity apply). State ADUs: none.[2] 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).[4] |
| Owner occupancy | No city-specific figure verified. The state minimum below applies; confirm local details with the city. 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).[4] |
| Permit steps and timeline | LADBS runs a Standard Plan Program: pre-approved plans go through a shorter plan check, then staff review your site for zoning and foundation. The City offers a free 1-story, 1-bedroom 455 sq ft plan called YOU-ADU.[1][3] 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).[4] |
| 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.[4] |
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Sources
Every fact above links to an official city or state page. Rules change; check the source before you build.
- [1] LADBS: Accessory Dwelling Unit checked Oct 2026
- [2] LA City Planning: ZA Memo 143, Dec 30 2024 checked Oct 2026
- [3] LADBS: ADU Standard Plan Program checked Oct 2026
- [4] HCD ADU Handbook (March 2026) checked Oct 2026