Accessory Structures in Fountain Valley, CA (2026)
6 verified accessory structures rules for Fountain Valley, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
In the City of Fountain Valley, California, a new detached ADU can be up to 850 sq. ft. (1,000 sq. ft. with more than one bedroom), needs only a 4 ft side and rear setback, and is limited to 16 ft in height. Permits are ministerial and deemed approved after 60 days.
Fountain Valley CA Accessory Dwelling Unit Standards
Light RestrictionsFountain Valley Municipal Code § 21.08.055(b)
(8) Attached and Detached Accessory Dwelling Units Maximum and Minimum Unit Size. (A) The minimum size of a new accessory dwelling unit shall be 150 square feet. (B) The maximum size for a new detached accessory unit shall be: (i) 850 square feet; or (ii) 1,000 square feet for an accessory dwelling unit that provides more than one bedroom. (C) The maximum size for a new attached accessory dwell...
ADU Impact Fees
In the City of Fountain Valley, California, an impact fee can be imposed only on an accessory dwelling unit of 750 sq. ft. or larger, and it must be charged in proportion to the square footage of the primary dwelling. Utility connection fees and capacity charges are excluded from that definition.
Fountain Valley CA ADU Impact Fee Rules
Light RestrictionsFountain Valley Municipal Code § 21.08.055(a)(16)
(16) Impact Fee. An impact fee for the development of an accessory dwelling unit may only be imposed for an accessory dwelling unit of 750 square feet or larger and shall be charged proportionately in relation to the square footage of the primary dwelling unit. For purposes of this section, "impact fee" has the same meaning as the term "fee" is defined in subdivision (b) of Section 66000 of the...
ADU Owner Occupancy
In the City of Fountain Valley, California, accessory dwelling units created after January 1, 2025 must be owner occupied, backed by a recorded covenant. Junior accessory dwelling units need the owner living in either the main dwelling or the junior unit, unless the owner is a governmental agency, land trust, or housing organization.
Fountain Valley ADU and JADU Owner Occupancy
Significant RestrictionsFountain Valley Municipal Code § 21.08.055
Accessory dwelling units created after January 1, 2025 shall be owner occupied and a covenant containing this restriction shall also be recorded for accessory dwelling unit's created after January 1, 2025. ... Owner-Occupied. ... The main dwelling or the junior accessory dwelling unit shall be owner-occupied. Notwithstanding the foregoing, owner-occupancy shall not be required if the owner is a...
ADU Rental Restrictions
In the City of Fountain Valley, California, an accessory dwelling unit can be rented separately from the main house, but only for a term longer than 30 days. Fountain Valley Municipal Code § 21.08.055 also bars selling the unit apart from the primary residence and requires a recorded covenant that binds future owners.
Fountain Valley ADU Rental Term and Sale Rules
Some RestrictionsFountain Valley Municipal Code § 21.08.055
Sold Separately. The accessory dwelling unit may be rented separate from the primary residence but may not be sold or otherwise conveyed separate from the primary residence, unless qualified as a sale or conveyance of accessory dwelling unit separate from primary residence under Government Code Section 65852.26. ... Rental. ... If the accessory dwelling unit is available for rent, the rental of...
Shed & Carport Rules
In the City of Fountain Valley, California, one detached accessory building cannot exceed 40% of the required rear yard area, all together 50%, and a shed over 120 sq. ft. must sit 5 ft from side and rear lines. Sheds of 120 sq. ft. or less with a ceiling of 7 ft or lower need no building permit.
Fountain Valley CA Shed and Accessory Building Rules
Some RestrictionsFountain Valley Municipal Code § 21.08.050(b)
(3) Detached Structures. (A) The floor area of any one detached accessory structure shall not exceed forty percent of the required rear yard area. The total floor area(s) of all detached accessory structures shall not exceed fifty percent of the required rear yard area; (B) A minimum of one thousand square feet shall be maintained as rear yard open space for single-family detached uses; (C) Det...
Garage Conversions
In the City of Fountain Valley, California, a garage can be converted into an accessory dwelling unit through a ministerial building permit. Fountain Valley Municipal Code § 21.08.055 requires no replacement parking, allows a 150 square foot expansion, and sets construction standards for any wall that replaces the garage door.
Fountain Valley Garage Conversion to ADU Rules
Some RestrictionsFountain Valley Municipal Code § 21.08.055
A demolition permit for a detached garage that is to be replaced with an accessory dwelling unit shall be reviewed with the application for the accessory dwelling unit and issued at the same time. ... Parking. ... No additional parking spaces shall be required. ... Minor Expansion. A minor expansion of not more than 150 square feet beyond the same physical dimensions as the existing accessory s...
Looking for Orange County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Fountain Valley city rules.
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