Santa Ana sets ADU and JADU rules in Municipal Code Section 41-194. Single-family lots may have one ADU and one JADU; multifamily lots follow separate conversion and detached caps.[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 | Detached ADU: up to 1,000 sq ft. Attached ADU: up to 1,000 sq ft or 50% of the primary residence floor area, whichever is less (may exceed 50% to allow an 800 sq ft unit). JADU: up to 500 sq ft inside the single-family home or attached garage. Minimum size 220 sq ft.[1] 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).[3] |
|---|---|
| Height | Detached: 20 ft or two stories. Attached: the height limit of the underlying zoning for the primary building.[1] 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).[3] |
| Setbacks | Rear and side: 4 ft. Front: same as existing zoning. No extra setback when converting an existing building. An ADU built above an existing garage that already encroaches needs at least 4 ft.[1] 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).[3] |
| Parking | One space for newly constructed units unless within 1/2 mile of public transit, created inside an existing building, in a historic district, not offered an on-street permit when one is required, on the same block as a car share, or a studio. No parking for a JADU.[1] 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).[3] |
| Owner occupancy | No owner occupancy for an ADU. A JADU requires owner occupancy in the main home or the JADU, with a recorded restrictive covenant at building permit issuance.[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).[3] |
| Permit steps and timeline | No city-specific figure verified. The state minimum below applies; confirm local details with the city. 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).[3] |
| Fees | Application review, permit and development impact fees may apply. Contact the city departments for current amounts.[1] 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.[3] |
Also worth knowing: ADUs and JADUs cannot be used as short-term vacation rentals; rentals must be 30 days or more. Each unit needs its own address.[1]
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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] City of Santa Ana: ADU/JADU Development Standards checked Oct 2026
- [2] Santa Ana Municipal Code 41-194 (ADUs and JADUs) checked Oct 2026
- [3] HCD ADU Handbook (March 2026) checked Oct 2026