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

Fairfield's setback requirements vary by zoning district. Under Section 25.20, single-family residential districts (R-L, R-M, R-MH) generally require a 20-foot front setback (25 feet if the lot fronts on an arterial street designated in the General Plan), a 5-foot interior side setback, a 10-foot rear setback (15 feet if abutting an arterial), and a corner side setback of 10 feet. For dwelling structures above two stories, side and rear distances between buildings on the same lot increase by 2 feet per additional story. Section 25.30 provides general development rules including encroachments: architectural features (eaves, sills, chimneys) may project up to 30 inches into a required yard; uncovered porches and decks under 30 inches high may extend into setbacks; HVAC equipment must be at least 3 feet from any side property line. Accessory dwelling units (ADUs) follow state-mandated reduced setbacks under Government Code 65852.2 (4-foot side and rear), preempting larger local standards. Setback measurements are taken under Section 25.51 from the property line, not from sidewalk or curb.