As of April 2026, California and Colorado are the only two states with a mandatory statewide code that forces a Class A fire-rated roof in wildfire zones, according to Headwaters Economics. Every other high-risk Western state leaves the decision to local building departments or has no wildfire roof rule at all. That gap matters because nearly 2.6 million homes across the Western U.S. sit at moderate or greater wildfire risk, carrying about $1.3 trillion in reconstruction value (Cotality Wildfire Risk Report, 2025). This report maps which states require a Class A roof, ranks where roof exposure is highest, and flags the states where the risk has outrun the code.
Key findings
- Two states mandate it statewide. California and Colorado are the only states with a mandatory statewide wildfire building code in effect as of April 2026 (Headwaters Economics, 2026). Both require Class A roof assemblies in mapped hazard zones.
- Risk is concentrated. California, Colorado, and Texas together account for roughly 70% of all Western homes at wildfire risk (Cotality, 2025).
- The biggest gap is Texas. Texas ranks third for homes at risk (243,136) yet has no statewide wildfire roof code, leaving the requirement to local jurisdictions (Cotality, 2025; Headwaters Economics, 2026).
- Class A is the ceiling. Under the International Wildland-Urban Interface Code, the highest-hazard class requires a Class A roof tested to ASTM E108 or UL 790 (ICC IWUIC, 2021).
- Wood is out. Wood shakes and wood shingles do not meet Class A and cannot be installed in mapped WUI zones in California, regardless of fire-retardant treatment (California WUI code, 2026).
- WUI scale is national. The wildland-urban interface holds 44.8 million housing units, about 39% of all U.S. homes, with California leading at roughly 5.1 million WUI units (U.S. Forest Service / USGS, Radeloff et al.).
Which states require a Class A roof?
As of April 2026, only California and Colorado enforce a Class A roof requirement through a mandatory statewide code (Headwaters Economics, 2026). Utah has passed a law requiring local jurisdictions to adopt a wildfire code by 2029. Oregon and Washington have drafted statewide codes that are not yet in effect. Every other Western state defers to local building departments. The table below ranks states by how binding their Class A roof mandate is.
| State | Statewide Class A roof mandate | Status / basis |
|---|---|---|
| California | Yes, mandatory statewide | Chapter 7A of the California Building Code; the California WUI code took effect Jan 1, 2026 in mapped Fire Hazard Severity Zones |
| Colorado | Yes, mandatory statewide | Statewide Wildfire Resiliency Code (2025 statute); local jurisdictions adopt by April 1 and enforce by July 1, 2026 |
| Utah | Coming (2029) | Law passed requiring local jurisdictions to adopt a wildfire code by 2029 |
| Oregon | Drafted, not in effect | Statewide code effort has not yet taken effect |
| Washington | Drafted, not in effect | Statewide code effort has not yet taken effect |
| Nevada | Partial / local option | Some statewide regulation; local governments may set stricter rules |
| Montana | Voluntary | Jurisdictions may voluntarily adopt a limited pre-approved code; enforcement limited |
| Arizona | No statewide code | Local governments may adopt their own regulations |
| Idaho | No statewide code | Local governments may adopt their own regulations |
| New Mexico | No statewide code | Local governments may adopt their own regulations |
| Wyoming | No statewide code | Local governments may adopt their own regulations |
Source: Headwaters Economics, “Tracking Western states’ diverse approaches to wildfire building codes,” 2026. Local jurisdictions in no-code states can and often do require Class A roofs on their own, so a home in Austin or Flagstaff may still face a Class A rule even where the state has none.
Where is wildfire roof risk highest?
California carries the most exposed housing stock by a wide margin, with 1,257,966 homes at moderate or greater wildfire risk and about $796 billion in reconstruction value (Cotality, 2025). Colorado and Texas follow. The ranking below reflects the number of single-family homes at moderate or greater risk, the strongest available proxy for how many roofs a wildfire code would touch.
| Rank | State | Homes at moderate+ wildfire risk | Reconstruction cost value | Statewide Class A mandate |
|---|---|---|---|---|
| 1 | California | 1,257,966 | $796.1B | Yes |
| 2 | Colorado | 318,783 | $146.2B | Yes |
| 3 | Texas | 243,136 | $95.4B | No (local option) |
| 4 | Oregon | 128,007 | $47.5B | No (drafted) |
| 5 | Arizona | 123,906 | $39.2B | No (local option) |
Source: Cotality (formerly CoreLogic) Wildfire Risk Report, 2025. Across the West, about 1.2 million of these homes fall into the very high risk band, roughly half of all at-risk homes.
The gap: where roof risk outruns the code
The clearest finding of this report is a mismatch between exposure and regulation. Two of the top five most exposed states, Texas and Arizona, have no statewide Class A roof mandate, and a third, Oregon, has a code that is drafted but not yet in force (Cotality, 2025; Headwaters Economics, 2026). In practice this means a homeowner re-roofing in a high-risk Texas county may face no state rule requiring a Class A assembly, even though the fire exposure rivals parts of California.
Only California and Colorado align a high risk ranking with a mandatory statewide roof code. Colorado’s rule reaches existing homes directly: a reroof that replaces 25% or more of the roof surface must meet Class A in adopting jurisdictions (Colorado Wildfire Resiliency Code, 2025). California’s 2026 WUI code applies to new construction and reroofing in mapped Fire Hazard Severity Zones. Elsewhere, the roof standard depends on the city or county, so two neighbors on opposite sides of a jurisdiction line can face different rules.
What makes a roof Class A under a wildfire code?
A Class A roof is the highest fire-resistance classification, defined by passing the roof-covering fire tests in ASTM E108 or UL 790 (ICC IWUIC, 2021). Under the International Wildland-Urban Interface Code, the most restrictive Extreme hazard class mandates a Class A roof assembly, ember-resistant vents tested to ASTM E2886, and ignition-resistant walls. Qualifying roof coverings and the excluded ones are listed below.
- Qualify as Class A: fiberglass-mat asphalt shingles, concrete tile, clay tile, metal panels and shingles, brick or masonry, and ferrous or copper sheet (ICC IWUIC, 2021; California WUI code, 2026).
- Do not qualify: untreated and, in California WUI zones, even fire-retardant-treated wood shakes and wood shingles cannot be installed in mapped zones (California WUI code, 2026).
- Assembly matters: some materials reach Class A only as part of a rated assembly with a specific underlayment, so the paperwork on the assembly, not just the shingle, is what a plan checker verifies (ASTM E108).
These same Class A coverings anchor the IBHS Wildfire Prepared Home standard, an insurer-backed program that treats the roof as the single most important surface for keeping embers out. For a deeper material breakdown, see The Roofing Brief guide to Class A fire resistant roofing materials and the option comparison for concrete roof tiles.
Does a Class A roof affect insurance?
A Class A roof can influence whether a home stays insurable in a wildfire state, though the effect varies by carrier and jurisdiction. Insurers increasingly tie renewal and pricing to roof material and roof age, and a combustible roof in a high-risk zone is a common trigger for non-renewal. The mechanism is underwriting risk, not a guaranteed discount, so homeowners should confirm any credit with their own carrier.
Related reading from The Roofing Brief covers which roof types insurers reward, when insurers drop or downgrade a roof by age, and how disaster exposure varies state by state.
Methodology and sources
This report synthesizes three public datasets and does not generate new field measurements. State code status comes from Headwaters Economics tracking of Western wildfire building codes (April 2026). Homes-at-risk counts and reconstruction values come from the Cotality (formerly CoreLogic) Wildfire Risk Report (2025), which measures single-family homes at moderate or greater risk. WUI scale figures come from U.S. Forest Service and USGS wildland-urban interface mapping (Radeloff et al.). Code requirements are drawn from the International Wildland-Urban Interface Code (ICC, 2021), California Chapter 7A and the 2026 California WUI code, and Colorado’s 2025 Wildfire Resiliency Code. Home-count rankings are a proxy for roof exposure, not a direct roof census, and code status changes as jurisdictions adopt new rules. Figures reflect the sources named and the dates shown; readers should verify current requirements with their local building department.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.