Riverside, CA Accessory Structures: Tiny Homes (2026)

5 or National Fire Protection Association 1192 park-model standards and third-party certified for that compliance. It must be licensed and registered with the California DMV, cannot move under its own power, must stay within California's highway-towing size limits, and must measure between 150 and 430 square feet as measured to the exterior wall faces, smaller than a standard ADU and far smaller than the code's cap on detached ADUs. 030(I): the undercarriage, axles, tongue, and hitch, must be fully screened and hidden from view, and the leveling or support jacks must sit on a paved surface rather than bare ground.

Mechanical equipment has to be built into the structure instead of mounted on the roof, exterior materials can't be single-piece composite, laminate, or interlocked metal sheathing, and the roof can't be wood shingle and must match the primary home's pitch and material. A MADU can't carry a separate street address from the primary dwelling and must connect to water, sewer, and electric utilities the same as a permanent structure. It's excluded from historic districts, Neighborhood Conservation Areas, and lots with a designated cultural resource, and it can't sit between the primary dwelling and the street in a front or street-side yard.