ADU rules in Rialto, CA — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
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.
Rialto Municipal Code Section 18.10.070 caps ADU size at 50 percent of the primary dwelling or 850 square feet (1,000 square feet for multi-bedroom units), whichever is more, never exceeding 1,200 square feet. Height is limited to 16 feet or one story; side and rear setbacks are four feet. One parking space is required unless the unit is within one-half mile walking distance of public transit or converted from existing space. The city's ADU program page adds that detached ADUs need separate gas, water, and electric meters, all new detached dwellings require solar panels, and designs must match the primary dwelling. Eleven pre-approved plans (499 to 1,200 square feet) are available. State law (Government Code Section 66323) mandates ministerial approval.
Building an ADU without permits triggers code enforcement and after-the-fact permitting; however, under AB 2533 (Government Code 66332) Rialto cannot deny a permit to legalize a unit built before January 1, 2020 unless substandard conditions exist.
Other ordinances people look up for this city. Green dot = verified primary-source excerpt.
Rialto, CA
Rialto requires permits for walls taller than 42 inches and building permits for all masonry and retaining walls. Block walls get three city inspections, and...
Rialto, CA
Barbed wire and razor wire are prohibited in all Rialto residential zones, and no sharp points may top any fence under six feet. City design standards also r...
Rialto, CA
Rialto caps household pets at four weaned dogs and cats combined, and no more than three of them may be dogs. The limit appears in Rialto Municipal Code Sect...
Rialto, CA
Backyard fires in Rialto are legal only as contained cooking or warming fires burning clean fuels such as propane, natural gas, charcoal, or untreated wood. ...
Rialto, CA
Removing a street or parkway tree requires prior written permission from the public services director, and the city's published criteria allow removal only o...
Rialto, CA
Rialto requires home-based businesses to obtain both a Home Occupation Permit from the Planning Division and a city business license. Under Rialto Municipal ...
Side-by-side rule comparisons with other cities in San Bernardino County.
See how other cities in San Bernardino County handle adu rules.
See how Rialto's adu rules rules stack up against other locations.
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