Santa Maria ADU rules

Minimum 150 sq ft. For ADUs approved under the city's general standards, the maximum is 850 sq ft for a studio or one bedroom and 1,000 sq ft for two or more bedrooms. An attached ADU is also capped at 50% of the main home's floor area, and ADUs are limited to 10% of lot area, but these limits can never force an ADU below 800 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]

Detached ADU on a single-family lot: 18 ft, or up to 20 ft to match the main home's roof pitch (16 ft if the lot also has a JADU). Detached ADU on a multifamily lot: 16 ft, or 18 ft near major transit or next to a multistory building. Attached ADU: 25 ft or the zone limit, whichever is lower, and no more than two stories.^[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]

4 ft side and 4 ft rear. Front setback follows the zone district. No setback is needed if the ADU replaces an existing structure in the same place and size. A new detached ADU must be at least 5 ft from the main home.^[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]

One space per ADU or per bedroom, whichever is less, and tandem parking is allowed. No ADU parking is needed within a half mile walk of public transit, in a historic district, for an ADU inside the house or an accessory structure, where on-street permits are required but not offered, or within one block of a car share vehicle.^[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]

No owner occupancy rule for ADUs in the city code. For a JADU, the owner must live in the main home or the JADU, and a recorded covenant is required before the building permit. ADUs and JADUs may be rented for 30 days or more, not less.^[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]

The city must approve or deny a complete application within 60 days, or it is deemed approved (unless you ask for a delay, or the ADU is filed with a new house).^[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).^[3]

No development impact fees for an ADU under 750 sq ft. At 750 sq ft or more, impact fees are charged in proportion to the main home's size. Conversions inside an existing home or structure need no new utility connection fee; new ADUs pay connection fees in proportion to their size or plumbing fixtures.^[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]