Understanding your FireLine score
How a wildfire score looks at the land around your home, and what California lets you do about it
What is a FireLine score?
FireLine is a wildfire tool from Verisk, a data company whose insurance-rating arm is known as ISO. It looks at the land around a specific address and estimates how exposed that property is to wildfire. Some insurance companies use FireLine; others use different wildfire models.
What it looks at
Fuel
Grass, brush, and trees that can feed a wildfire.
Slope
Steeper ground can make a fire spread faster and burn hotter.
Access
Limited or dead-end roads can slow down fire engines.
Verisk's materials also describe layers for wind-blown embers, weather, and past wildfire activity.
The scale: 0 to 30
Lower is better. Verisk groups scores this way:
- 0 Negligible
- 1 Low
- 2 to 3 Moderate
- 4 to 12 High
- 13 to 30 Extreme
Two things to keep in mind
- A score of 0 is not zero risk. Embers can travel a long way, and your home's construction and the houses around it matter too.
- Verisk does not publish its formula. Be wary of online calculators. Your insurance company can tell you your actual score.
Your rights in California
Under California's Safer from Wildfires regulation, insurance companies that use wildfire risk to set your price must give you their wildfire risk score:
- when you apply for a policy,
- before your policy renews, or before the company declines to renew it, and
- when you finish a wildfire safety project and ask for an updated score.
They must explain the score, including how you could lower it and what you could save. You can appeal a score you think is wrong, in writing or by phone, and your agent can submit the appeal for you. If it is denied, call the California Department of Insurance at 800-927-4357.
Can I lower my score?
FireLine is based mostly on the land around your home, much of which is out of your hands. Clearing brush on your own property may help, but upgrades to the house itself may not change the FireLine number. Instead, those insurance companies must give you credit in your premium for steps like:
- a Class A fire-rated roof,
- a 5-foot ember-resistant zone around the house,
- ember- and fire-resistant vents, and enclosed eaves,
- clearing brush to meet defensible space rules,
- a Firewise USA neighborhood.
Safety work can lower your premium, but it does not guarantee that an insurance company will accept or renew a particular home.
What do the fire ratings mean?
Three different systems. Three different questions.
CAL FIRE Fire Hazard Severity Zone
The question: what wildfire conditions should this whole area expect? CAL FIRE maps land as Moderate, High, or Very High hazard, based on vegetation, terrain, fire weather, fire history, and blowing embers. CAL FIRE says the maps measure hazard over a 30 to 50 year period and do not consider home hardening or brush clearing. The California Department of Insurance says the maps are not used for insurance rates or decisions about which homes to insure. They guide local planning, building rules, and disclosures when you sell.
FireLine wildfire score
The question: how exposed is this property to wildfire, based on the land around it? Verisk scores fuel, slope, and road access, from 0 (negligible) to 30 (extreme). A low score is favorable, but it does not mean zero wildfire risk.
ISO Public Protection Classification (Protection Class)
The question: if a fire starts in this house, how well can the local fire department put it out? Verisk rates emergency communications, the fire department, and the water supply, from Class 1 (best) to Class 10. A Class 2 is excellent, but it is not a measure of a home's wildfire exposure.
Why can two neighboring homes have different scores?
Picture two homes in the same Very High hazard zone. One sits in a built-out neighborhood on flat ground, with irrigated yards, several ways in and out, and a hydrant down the street. The other sits on a brushy hillside at the end of a long, narrow road. They share a CAL FIRE zone because they share a region, but the first home will likely have a much lower FireLine score, and it may have a better Protection Class too, because it is closer to water.
Important: embers, wind, building features, and nearby structures can still create real wildfire exposure for any home. Insurance companies may use other models and factors beyond FireLine.