What does it mean if my house is in a Very High zone?

Three concrete things: sellers must disclose it in every sale; new construction and major rebuilds must meet Chapter 7A wildfire-resistant building standards (ember-resistant vents, tempered glazing, ignition-resistant siding and decking); and the defensible-space requirements of PRC 4291 — maintaining vegetation clearance around the structure — apply and are inspected in many jurisdictions.

What is the difference between SRA and LRA?

Responsibility areas describe who is financially responsible for wildfire protection: the State Responsibility Area (SRA) is where CAL FIRE has that duty — generally unincorporated wildlands — while the Local Responsibility Area (LRA) is where cities and counties have it. CAL FIRE maps all three severity classes in the SRA; in the LRA, state law requires local adoption of the mapped zones, and recent map updates extended Moderate and High class mapping into cities as well.

Does the zone class affect my insurance premium?

The zone maps are a state designation, not an insurer's rating tool — carriers use their own wildfire models. In practice the same terrain characteristics drive both, so Very High areas are where availability and pricing pressure concentrate, and where the FAIR Plan is most often the fallback. Mitigation (defensible space, home hardening) is increasingly recognized in California's insurance rules.

My neighborhood burned decades ago but isn't in a zone — why?

The maps classify hazard based on physical conditions — fuels, slope, weather, ember exposure — under the current mapping methodology, not on fire history alone. Boundaries also stop at the data's resolution: parcels near a zone edge can share most of the conditions of the zone next door, which is why checking the exact address matters.

CAL FIRE Fire Hazard Severity Zones: Moderate vs High vs Very High

California maps Fire Hazard Severity Zones in three classes — Moderate, High, and Very High — based on how a wildfire would behave in an area: fuels, slope, fire weather, and ember exposure. The class a property falls in drives building codes, defensible-space rules, disclosure obligations, and increasingly, insurance conversations.

How the classes are drawn

CAL FIRE’s model scores each area on the ingredients of fire behavior: vegetation (fuels), topography (fire runs faster uphill), typical fire weather (wind, humidity), and — critically since the 2007-era methodology — ember production and exposure, because most structures lost in wildfires ignite from wind-blown embers rather than the flame front. The scores bucket into Moderate, High, and Very High. The maps were comprehensively updated statewide in the mid-2020s, expanding zoned area in many Bay Area counties.

What each class means for an owner

Class	Practical effect
Moderate	Mapped and disclosed where required; baseline wildland-urban building code applies in the SRA
High	Same, with Chapter 7A building standards for new construction in the SRA and in LRA zones as adopted
Very High	Statutory seller disclosure everywhere; Chapter 7A construction standards; PRC 4291 defensible-space duty; local vegetation inspections common

Reading a listing’s disclosure

California’s Natural Hazard Disclosure statement asks two separate wildfire questions: whether the property is in a Very High Fire Hazard Severity Zone (either responsibility area), and whether it is in a wildland SRA where the state may not be obligated to defend every structure. A “yes” on either is a prompt to look at the map, not a verdict — the zone class of the parcel next door can differ, and mitigation on the specific property matters more than the label.

Bay Area context

The Very High zones cluster along the hill margins where neighborhoods meet wildland: the Oakland and Berkeley hills (site of the 1991 Tunnel Fire), Orinda and Moraga, the Peninsula ridge from Woodside south, Marin’s canyon towns like Mill Valley, and the North Bay hills around Santa Rosa and Napa. Our city pages show the share of each city in each severity class.

Check a specific address: the free sitelume interactive map shows which mapped zones any SF Bay Area address falls in — layer by layer, no sign-up.

Frequently asked questions

What does it mean if my house is in a Very High zone?: Three concrete things: sellers must disclose it in every sale; new construction and major rebuilds must meet Chapter 7A wildfire-resistant building standards (ember-resistant vents, tempered glazing, ignition-resistant siding and decking); and the defensible-space requirements of PRC 4291 — maintaining vegetation clearance around the structure — apply and are inspected in many jurisdictions.
What is the difference between SRA and LRA?: Responsibility areas describe who is financially responsible for wildfire protection: the State Responsibility Area (SRA) is where CAL FIRE has that duty — generally unincorporated wildlands — while the Local Responsibility Area (LRA) is where cities and counties have it. CAL FIRE maps all three severity classes in the SRA; in the LRA, state law requires local adoption of the mapped zones, and recent map updates extended Moderate and High class mapping into cities as well.
Does the zone class affect my insurance premium?: The zone maps are a state designation, not an insurer's rating tool — carriers use their own wildfire models. In practice the same terrain characteristics drive both, so Very High areas are where availability and pricing pressure concentrate, and where the FAIR Plan is most often the fallback. Mitigation (defensible space, home hardening) is increasingly recognized in California's insurance rules.
My neighborhood burned decades ago but isn't in a zone — why?: The maps classify hazard based on physical conditions — fuels, slope, weather, ember exposure — under the current mapping methodology, not on fire history alone. Boundaries also stop at the data's resolution: parcels near a zone edge can share most of the conditions of the zone next door, which is why checking the exact address matters.