Fremont ADU rules

New attached ADU: up to 1,000 sq ft of interior livable space. New detached ADU: up to 1,200 sq ft. Conversion of existing floor area: no size limit. JADU: up to 500 sq ft entirely within the single-family residence, including an attached garage. Garages, carports, covered porches and similar do not count toward ADU size.^[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).^[3]

New detached on a single-family lot: 16 ft, or 18 ft within a half-mile walk of a major transit stop or high-quality transit corridor, plus 2 ft to match the main roof pitch. New attached to a single-family dwelling: 30 ft or the zoning height for the main home, whichever is lower. Conversion of existing floor area: no height limit.^[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).^[3]

New attached or detached: 4 ft side and rear. Front setbacks match the primary dwelling unless that would block a statewide exemption ADU. Conversion in place: no new setback (with up to 150 sq ft expansion for entry).^[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).^[3]

No additional parking for an ADU, and no replacement parking when a space is demolished or converted for an ADU.^[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).^[3]

No owner occupancy for the primary home or the ADU. If a JADU shares a bathroom, the owner must live in the residence or the JADU (with listed exceptions for agencies and nonprofits).^[2]

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]

Ministerial review. Completeness notice within 15 business days. A permit must issue within 60 days of a complete application when there is an existing dwelling on the lot. The ADU needs its own building permit, separate from any remodel of the main house. Preapproved plans get expedited review and lower permitting costs.^[2][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 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.^[3]