ADU rules in Santa Ana

Santa Ana allows ADUs, attached or detached, in every zoning district where residential or mixed-use development is permitted. A new detached ADU may be up to 1,000 sq ft, two stories or 20 ft tall, with 4 ft side and rear setbacks and 15 ft of separation from the main house (reducible to fit an 800 sq ft unit). The code allows one ADU on a single-family lot, but state law (Gov. Code 66323(a)) lets an owner combine a conversion ADU and a JADU with one detached new-construction ADU of up to 800 sq ft. Lots with an existing apartment building may add up to eight detached ADUs (never more than the existing unit count), and lots with a proposed apartment building up to two.

Attached ADUs are allowed wherever residential or mixed-use development is permitted. An attached ADU may be up to 1,000 sq ft but no more than 50 percent of the main home's habitable space, except that the 50 percent limit may be exceeded to reach 800 sq ft. It may be as tall as the main building allows, with 4 ft side and rear setbacks. Converting space inside the existing home or an existing accessory structure is not subject to the size, height or setback limits.

Table 41-194.3 sets the 1,000 sq ft maximum for both attached and detached ADUs and a 220 sq ft minimum for every unit type. Front-yard setback, lot coverage, open space and separation standards must all give way to allow an ADU of up to 800 sq ft. The table does not say how floor area is measured; state law states its size floors in interior livable space. Detached ADUs are limited to two stories or 20 ft, measured from the lowest adjacent grade.

Nothing in Sec. 41-194 requires the owner to live on a lot with an ADU, and state law bars such a rule (Gov. Code 66315); the city's standards page says 'No owner occupancy requirements' for ADUs. JADUs differ: Sec. 41-194.5 still requires a recorded covenant 'consenting that either the primary dwelling unit or the JADU be owner-occupied' for every JADU. Since 1-1-2026, however, Gov. Code 66333(b) allows owner occupancy only when the JADU shares sanitation facilities with the house, so a JADU with its own bathroom cannot lawfully be subject to that condition. The covenant's other terms (no separate sale, size limits) remain valid.

The exemption list is broad, so most conversions and transit-adjacent ADUs owe no parking at all. Table 41-194.3 sets 'Minimum Parking 1 space' for attached and detached ADUs and none for JADUs, and allows tandem parking on a driveway. When a garage or carport is demolished for an ADU, the demolition permit must be issued together with the ADU permit.

ADU and JADU permits are ministerial: the executive director of the Planning and Building Agency approves or denies them based only on completeness, conformance with the code, and payment of the review fee, with no public hearing. A disapproval can be challenged by filing a minor exception application under Article V of Chapter 41. State law (Gov. Code 66317) requires a decision within 60 days of a complete application.

SAMC Sec. 8-3401 makes it unlawful to offer or rent a home-sharing, short-term or vacation rental 'for less than thirty (30) days', and Sec. 8-3400 defines both kinds by stays under 30 consecutive days (Ords. NS-3060, NS-3061 and NS-3072 of 2024); the city's ADU standards page repeats the 30-day rule. State law adds a stricter floor for JADUs (Gov. Code 66333(g)) and state-exempt ADUs (66323(e)): terms must be longer than 30 days. Legal ADUs are exempt from the city's proactive rental inspection program (Sec. 8-1963(C)). The separate-sale clause in Sec. 41-194.2(H) still cites Gov. Code 65852.26, the former number of today's 66341.