The short version
- Most homes ignite from embers, not from the main fire front.
- Start with Zone 0, vents and gutters. They are cheap and matter most.
- Save the roof, windows and siding upgrades for when you remodel.
- The IBHS Wildfire Prepared Home checklist is a good research-backed target.
How homes catch fire in a wildfire
Homes ignite in three ways: windblown embers, radiant heat from nearby burning material, and direct flame contact. Embers are the biggest threat because they can travel a mile or more ahead of a fire and find their way into small openings or onto anything that burns next to the house. Hardening means closing those openings and removing those fuels, one part of the house at a time.
See the difference
Where to start
Work from the cheapest, highest impact fixes toward the larger projects. A weekend and a few hundred dollars in supplies covers the first column below. The second column is where to put your money when you remodel, reroof or replace windows.
| Area | Why it matters | Do first | Bigger upgrade |
|---|---|---|---|
| Zone 0 (0 to 5 ft) | Embers pile up against the walls and ignite mulch, plants and stored items. | Remove mulch and combustibles. Gravel or pavers. | Noncombustible fence sections, hardscape |
| Vents | Wind pushes embers into the attic and crawl space. | 1/8 inch metal mesh over every vent | Tested ember-resistant eave and gable vents |
| Gutters and roof | Debris in gutters and valleys ignites at the roof edge. | Clean gutters and roof. Metal gutter guards. | Class A roof assembly, bird stops on tile |
| Decks and fences | Debris under decks and wood fences carry fire to the house. | Clear under the deck. Move furniture and cushions. | Noncombustible decking near the house, metal fence sections |
| Windows and doors | Heat breaks glass, and gaps let embers in. | Weatherstrip doors and the garage door. Metal screens. | Dual-pane windows with tempered glass |
| Siding | Embers and burning debris collect where walls meet the ground or deck. | Keep 6 inches of noncombustible material at the base of walls | Fiber cement, stucco or masonry siding |
The Wildfire Prepared Home standard
The Insurance Institute for Business & Home Safety (IBHS), a research group funded by insurers, runs a program called Wildfire Prepared Home. Homes that meet its checklist can earn a designation, and in some states insurers recognize it. Its base level lines up closely with this guide: a Class A roof, ember-resistant vents or 1/8 inch metal mesh, metal gutters, a noncombustible 0 to 5 foot zone with no wood fencing attached to the house, and 6 inches of noncombustible material at the base of the walls. The higher level adds items like tempered dual-pane windows, noncombustible gutter guards and noncombustible decks.
Even if you never apply for the designation, its checklist is a solid, research-backed to-do list.
Go deeper
These are the official guides we lean on most. Each is free and kept up to date by the agency that publishes it.
- CAL FIREHome Hardening
California's official guide to how roofs, vents, windows, siding and decks resist embers and flame, with a link to a free self-assessment.
- IBHSWildfire Prepared Home: How-To Prepare Checklist
The research group behind the Wildfire Prepared Home designation, with a step-by-step checklist of science-based upgrades.
- California Department of InsuranceSafer from Wildfires
The state's list of home and property mitigation actions insurers recognize. Under state rules, insurers that factor wildfire risk into your rate must give credit for these measures, tell you your wildfire risk score, and explain how much each step would lower your premium. Ask your insurer for that explanation.
Siding
Burning debris and embers collect where walls meet the ground, a patio or a deck. Keep at least 6 vertical inches of noncombustible material, such as concrete foundation or fiber cement trim, at the base of every exterior wall and above any attached deck. If you replace siding, fiber cement, stucco and masonry resist ignition far better than wood or vinyl.
Don't forget the inside of the plan
Hardening improves the odds your home survives. It does not make it safe to stay. Keep a go bag ready, know two ways out of your neighborhood, and sign up for your county's emergency alerts.
Free download
The Fireproof Homes Wildfire Guide
A one-page walk-around checklist plus every guide on this site, in one printable PDF.
Sources
- IBHS and Washington Insurance Commissioner: Wildfire Prepared Home checklist (PDF)
- IBHS: Wildfire Prepared Home How-To Prepare Checklist
- Insurance Institute for Business & Home Safety (IBHS): Wildfire research
- CAL FIRE: Home Hardening
- California Department of Insurance: Safer from Wildfires
- CAL FIRE: Ready for Wildfire
- Cal OES: Defensible space, improve your home's chance of surviving a wildfire
This guide is general information, not professional advice. Building codes and defensible space rules vary by state, county and fire district. Your local fire department or a qualified contractor can tell you what applies to your home. No home is fireproof. Read our full disclaimer.