California uniformly classifies and maps Fire Hazard Severity Zones statewide, with mandatory building, disclosure, and defensible space rules tied to zone designations.
Government Code Section 51178 and Public Resources Code Section 4202 require the State Fire Marshal and CAL FIRE to designate Fire Hazard Severity Zones (Moderate, High, Very High) across both State Responsibility Areas and Local Responsibility Areas. Local agencies must adopt the state maps within 120 days of release and cannot reduce zone classifications. Properties in Very High zones trigger Chapter 7A ignition-resistant construction standards in the California Building Code, AB 38 home-hardening disclosures at sale, and Public Resources Code 4291 defensible space duties. The 2024-2025 statewide map updates apply to all jurisdictions.
Failure to comply with zone-based building, disclosure, or vegetation rules can result in stop-work orders, denial of insurance, and civil penalties.
See how Sonoma's wildfire zones rules stack up against other locations.
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