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

Table 28.21B under Solano County Code Section 28.21.30 governs main buildings and dwellings in the four Exclusive Agricultural zoning districts: A-20 (20-acre minimum lot), A-40, A-80, and A-160 (160-acre minimum lot). Every one of those districts shares the same yard standard: a 30-foot front setback that must also clear at least 50 feet from the street centerline unless the Zoning Map shows a different building line, 20-foot side setbacks on each side, a 25-foot rear setback, and a 10-foot minimum separation between structures on the same lot. Secondary dwellings carry identical setbacks but are capped at 2,400 square feet under Section 28.72.10(B)(3)(a). Building height in these agricultural districts tops out at 35 feet for houses and 50 feet for agricultural processing structures, subject to the exceptions in Section 28.93.

Table 28.31B under Section 28.31.30 sets parallel standards for the three Rural Residential districts, R-R 2-1/2 (2.5-acre minimum lot), R-R 5, and R-R 10. The front setback matches the agricultural standard at 30 feet with the same 50-foot-from-centerline floor, and the rear setback is also 25 feet. Side setbacks are tighter here at just 10 feet each, half of what the agricultural zones require, and structures on the same lot must still sit at least 10 feet apart. Height is capped at 35 feet. Section 28-97 governs how setbacks are measured and what projections are allowed to encroach into them, Section 28.93 lists height exceptions, and Section 28.99 addresses Airport Flight Obstruction Areas near Travis Air Force Base. Detached agricultural accessory buildings follow separate standards under Table 28.21C, including a 60-foot front setback or placement on the rear 50 percent of the lot.