Riverside County, CA Accessory Structures: Shed Rules (2026)

Detached, non-habitable accessory buildings and structures - including sheds, workshops, and storage barns - in unincorporated Riverside County are regulated by Ordinance No. 348, Section 18.18 (added by Ord. 348.4997, effective 4/28/2023). These standards apply to lots whose principal use is a one-family dwelling; habitable structures fall under the ADU rules of Article XIXj instead. Where the zone requires a rear yard, a detached accessory building must meet that rear-yard setback (Sec. 18.18.C.3.a). It may not be located closer to the front lot line than the principal dwelling, though the Planning Director may allow a minimum 25-foot front setback where that standard is infeasible (Sec. 18.18.C.3.c). Building height may not exceed two stories or 40 feet unless a greater height is approved under Section 18.34 (Sec. 18.18.C.3.e). The structure may not contain a kitchen (Sec. 18.18.C.3.j), may not be used for overnight accommodations (Sec. 18.18.C.3.i), and may not be rented separately from the house (Sec. 18.18.C.3.h). Bare, unpainted metal buildings are prohibited on lots one acre or smaller (Sec. 18.18.C.3.f). If a single accessory building - or the total of all accessory buildings on a lot - equals or exceeds 5,000 square feet, the Planning Director may require a plot plan and environmental review (Sec. 18.18.C.2). A building permit is generally required; consult the County Building & Safety Department for size thresholds.