San Diego County, CA Fire Regulations: Wildfire Zones (2026)

Large portions of unincorporated San Diego County are designated Very High Fire Hazard Severity Zones (VHFHSZ) by CAL FIRE and lie within the Wildland-Urban Interface (WUI). The County Consolidated Fire Code adopts WUI fire-area standards (Chapter 47 / Appendix II-A) that impose stricter requirements on new construction and on properties in hazardous fire areas. Under the County's Wildland-Urban Interface amendments (Sec. 4707), the building official sets minimum structure setbacks in WUI fire areas; Sec. 4707.1.1 requires buildings to be set back at least 30 feet from property lines and open-space easements unless zoning requires more, with limited exceptions. New homes in WUI areas must use ignition-resistant construction (such as Class A roofing, ember-resistant vents, and fire-resistant exterior materials) per the California Building Code Chapter 7A. The 100-foot defensible space requirement (County Code Secs. 68.401-68.406 and PRC section 4291) applies throughout these areas, and roads must meet minimum width and access standards (Appendix II-A) - e.g., 24 feet for roadways serving more than two single-family dwellings. Combustible vegetation along driveways and around structures must be cleared, and outdoor fires and fireworks are restricted or banned. The County Fire Authority, local fire protection districts, and CAL FIRE share enforcement; the Fire Authority Having Jurisdiction reviews discretionary projects for compliance.