How fire hazard severity zones affect your insurance premium

What FHSZ maps are (and are not)

Fire Hazard Severity Zones are CAL FIRE’s statewide map of the physical conditions that make wildfire possible over the long run: fuel, slope, weather, and the ember cast that comes off nearby wildland. They grade land as Moderate, High, or Very High. CAL FIRE is explicit that these are hazard maps, not risk maps: they say how intense a fire could be if one arrives, not how likely a given house is to burn or how much damage would result.

They exist to drive building codes and vegetation rules. A Very High zone triggers Chapter 7A construction standards for new and substantially remodelled homes, defensible-space requirements, and disclosure when a house is sold. They were not built to price insurance, and — the key point of this article — insurers do not use them for that. Our WUI vs. FRAP guide covers how the CAL FIRE map relates to the national wildland-urban interface classification FireRiskHere shows.

Looking up your parcel

The Office of the State Fire Marshal publishes an address-searchable viewer for the current zone maps (osfm.fire.ca.gov → Fire Hazard Severity Zones). There are two layers: the State Responsibility Area map (rural and unincorporated land CAL FIRE protects), which took effect April 1, 2024, and the Local Responsibility Area recommendations for cities and districts, released in phases between February and March 2025 and adopted into local ordinances during 2025. Your county or city planning department can tell you which version is in force where you live.

Real-estate disclosures reference these zones, and so does the state’s defensible-space inspection program, so it is worth knowing your zone even though your insurer is looking at something else.

What insurers use instead: risk scores

Insurers price wildfire with parcel-level risk scores from commercial vendors (names you may see on a declaration or a non-renewal letter include FireLine, CoreLogic’s wildfire risk score, and Z-FIRE), or with their own catastrophe models. These blend the same physical inputs as the FHSZ map with fine-grained data — the vegetation within a few hundred feet of the structure, slope at the parcel, road access, distance to a fire station, and often the roof and construction type from imagery. Two houses in the same Very High zone can score very differently, and a house just outside any zone can score badly.

Since 2023, California regulation (the “Safer from Wildfires” rules) requires admitted insurers to disclose your wildfire risk score, explain what mitigation would improve it, and provide an appeal process. If a quote or a non-renewal cites wildfire risk, ask for the score and the vendor by name; the insurer must answer.

The 2024–2025 zone changes

The 2024 SRA map and the 2025 LRA recommendations were the first comprehensive updates in more than a decade and added “Moderate” and “High” zones to the LRA maps, which had previously shown only Very High. Millions of additional parcels landed in a zone for the first time. This changed building-code and disclosure obligations, but by itself did not change anyone’s premium: insurers were already scoring those parcels at the address level. Where premiums did move in 2024–2025, the drivers were the state’s new rate rules (forward-looking catastrophe models and reinsurance costs allowed in admitted rates) and reinsurance prices — not the map redraw.

The levers you control

You cannot change your zone. You can change most of what a risk score and an underwriter look at within 100 feet of the house, and the Safer from Wildfires rules make insurers put a filed discount on each of these:

• 0–5 ft ember-resistant zone — nothing combustible touching or under the structure: no bark mulch, wood fences attached to the house, or plants against the wall. (A statewide “Zone 0” rule for Very High zones has been in rulemaking; check the Board of Forestry for its current status.)
• Roof — Class A; the single most-weighted structural item.
• Vents — ember-resistant (1/8″ mesh or listed vents), including under-eave and foundation vents.
• Eaves, windows, decks — enclosed eaves, multi-pane or tempered glass, non-combustible or cleared under-deck.
• Defensible space — 5–30 ft lean and green, 30–100 ft thinned; document with dated photos.
• Community — Firewise USA recognition or a Fire Risk Reduction Community listing carries its own discount and changes carrier appetite for the neighborhood.

Appealing a score

The appeal right applies to admitted carriers. Ask, in writing, for: the score, the vendor/model, the specific factors that drove it, and the appeal instructions. Then send evidence that the model got the parcel wrong (an outdated aerial image showing vegetation you have since cleared is the classic case) or that mitigation is in place. Insurers must respond; if one does not, or gives no appeal path at all, the California Department of Insurance takes complaints online and at 1-800-927-4357. An appeal changes the score for that company only — every carrier runs its own — so a successful appeal at one insurer is a reason to re-quote the others with the same packet.

Awareness only. Follow local authorities for evacuations, and your insurer or agent for anything about your policy.