Riverside, CA Accessory Structures: ADU Permits (2026)

Riverside Municipal Code Chapter 19.442 (Accessory Dwelling Units) implements California state ADU law including SB 9, AB 881, SB 13, and AB 2221 through ministerial permit review. Applications go to the Community & Economic Development Department (CEDD) Planning Division and are decided on objective standards only — no public hearings, no discretionary findings. State law caps the decision on a complete application at 60 days under Gov. Code §65852.2(b). Detached ADUs are allowed up to 1,200 sq ft; attached ADUs up to 50% of the primary dwelling floor area, with state by-right minimums of 800 sq ft and 16-foot height regardless of underlying zone. The standard side and rear setback is 4 feet for one-story ADUs up to 16 feet tall; ADUs taller than 16 feet follow the underlying zone's setback. Front and street-side setbacks follow the underlying zone. There is no minimum lot size to establish an ADU, MADU, or JADU per RMC 19.442.030. The Riverside ordinance has been reviewed by the California Department of Housing & Community Development (HCD) for compliance with state ADU law. AB 1033 (2023) condo conversion has not been adopted in Riverside; sales separate from the principal dwelling remain unavailable.