Accessory Structures in Rialto, CA (2026)
5 verified accessory structures rules for Rialto, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Rialto allows one ADU plus one junior ADU per single-family lot with ministerial approval within 60 days under Rialto Municipal Code Section 18.10.070. Detached ADUs are limited to 16 feet in height, four-foot side and rear setbacks, and 1,200 square feet maximum.
ADUs allowed citywide; ministerial approval in 60 days
Few RestrictionsCity of Rialto ADU program page; Rialto Municipal Code Section 18.10.070
An ADU is a secondary housing unit that is built on the same lot as the primary residence. ... Development standards for ADUs, including height limits, size limits, lot coverage, and design guidelines can be located in the Rialto Municipal Code, Section 18.10.070. ... All detached accessory dwelling units require separate gas, water, and electric meters. All new detached dwellings require solar...
ADU Owner Occupancy
Rialto Municipal Code Sec. 18.10.070(H) does not require an owner to live in the primary house or the accessory dwelling unit. An investor can build an ADU, keep both units as rentals, and never occupy the property. The one exception is a junior accessory dwelling unit, where owner occupancy of either the primary residence or the JADU is mandatory.
Rialto ADUs Need No Owner-Occupant
Few RestrictionsRialto Municipal Code Sec. 18.10.070(H)
Owner occupancy shall not be required of either the primary unit or the accessory dwelling unit. In the case of a junior accessory dwelling unit owner occupancy shall be required of either the primary unit or the junior accessory dwelling unit.
ADU Rental Restrictions
Rialto Municipal Code Sec. 18.10.070(H) sets a firm floor on accessory dwelling unit tenancies: any rental must run longer than thirty days. The rule bars ADUs from operating as short-term or vacation rentals, though it places no cap on how long a lease can run, and it applies regardless of whether the primary home or the ADU itself is rented.
Rialto ADU Rentals Must Run 30+ Days
Some RestrictionsRialto Municipal Code Sec. 18.10.070(H)
The accessory dwelling unit may be occupied without occupancy limitations, but if rented, such rental shall be for a period greater than thirty days.
Shed & Carport Rules
Rialto lists accessory buildings and gazebos among work requiring a building permit. Under Municipal Code Section 18.52.030, detached accessory buildings may occupy at most 25 percent of the rear yard and need 10 feet of separation from the house if over 120 square feet.
Sheds need permits; rear-yard coverage capped at 25 percent
Some RestrictionsRialto Municipal Code Section 18.52.030 - Location of accessory buildings
An accessory building may be located within five feet of any interior property line adjacent to the rear yard area. ... An accessory building having more than one hundred twenty square feet of roof area shall be separated from the main structure on the lot a minimum distance of ten feet.
Garage Conversions
Rialto ministerially approves conversion of an existing, legally permitted garage into an ADU with no new setbacks and no replacement parking, but the garage door must be replaced with windows or doors matching the home. Unpermitted units built before 2020 can be legalized under AB 2533.
Garage-to-ADU conversions allowed; garage door must be removed
Some RestrictionsCity of Rialto, Public Information Resource for AB 2533 and Third Party Inspection; Rialto Municipal Code Section 18.10.070(K)
Unpermitted Accessory Dwelling Units (ADU) or Junior Accessory Dwelling Units (JADU) constructed before January 1, 2020 may request to apply the provisions of Government Code 66332. Before making the request to the city and submitting an application for a permit, the homeowner may obtain a confidential third-party code inspection from a licensed contractor to determine the unit's existing condi...
Looking for San Bernardino County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Rialto city rules.
Accessory Structures in San Bernardino County →