Fontana, CA Building Setbacks & Zoning: Lot Coverage Limits (2026)

Lot coverage in Fontana refers to the share of a parcel occupied by the footprints of buildings, carports, and enclosed accessory structures, expressed as a percentage of lot area. FMC Title 17 sets coverage maxima by zone. Typical figures are 40 percent for standard R-1 single-family zones, 50 percent for small-lot R-1 and R-2 zones, and 60 percent or more for R-3 and mixed-use multi-family zones. Non-enclosed structures such as open patios, pools, and driveways generally do not count toward lot coverage but may count toward separate impervious-surface caps under stormwater rules. Roof eaves up to 2 feet are typically excluded. California Government Code Section 65852.2 requires Fontana to allow an ADU of at least 800 square feet even if adding it would exceed standard lot-coverage limits. Setbacks combined with coverage caps typically constrain how far a primary home can expand. Accessory structures under 120 square feet may be exempt from permit but still count toward coverage in many cases. Detached garages, workshops, and cabanas all count. Larger-lot zones (R-E Estate) have lower coverage ratios to preserve open space.