Riverside County, CA Building Setbacks & Zoning: Setback Rules (2026)

Building setbacks in unincorporated Riverside County are set by zone in Ordinance No. 348. For the common R-1 (One-Family Dwellings) zone, Section 6.2 establishes the minimum yards. The front yard 'shall be not less than 20 feet, measured from the existing street line or from any future street line as shown on any specific plan of highways, whichever is nearer the proposed structure.' Side yards 'on interior and through lots shall be not less than ten percent of the width of the lot, but not less than three feet in width in any event, and need not exceed a width of five feet'; on corner and reversed corner lots, the street-side yard 'shall be not less than ten feet' (or up to 20% of lot width on narrow lots). The rear yard 'shall not be less than ten feet.' Required yards must be kept open from ground to sky, with only limited encroachments permitted under Section 18.19 - eaves up to 3 feet, cornices up to 1 foot, and certain unenclosed stairways. Setbacks differ in other zones (R-A, R-R, R-2, R-3, agricultural, etc.) and can be overridden by an asterisk legend on the zoning map (Section 18.35) or by an adopted specific plan. Because the correct setback depends entirely on the parcel's zone classification, owners must confirm their zone with County Planning before designing an addition or new structure.