Class A roofs in San Jose fire hazard zones: what changed

What changed in 2025 and 2026

CAL FIRE released updated Fire Hazard Severity Zone maps in February 2025, and the San Jose City Council adopted them by ordinance on June 17, 2025. The city's very-high hazard acreage grew from roughly 3,000 acres to about 7,200, the largest increase of any Bay Area city.

Then, effective January 1, 2026, California consolidated its wildfire construction rules, which had been spread across the Building Code, Residential Code and Fire Code, into a single wildland-urban interface code in Title 24 Part 7. Under it, re-roofs in mapped hazard zones, including High zones inside city limits that were previously exempt, require a Class A roof assembly.

Which parts of San Jose are affected

The city's wildland-urban interface is concentrated in two areas with a history of serious fires: the Almaden Valley on the southwest side and the East Foothills near Alum Rock Park. The 2025 map added Moderate and High zones as well as expanding the very-high zones, so houses a little further from the hills may now be inside a zone too.

The reliable way to know is to check. The City of San Jose publishes a Fire Hazard Severity Zone finder where you type your address, and CAL FIRE has its own statewide viewer. We look up every parcel before writing a re-roof scope.

What a Class A assembly means

Class A is the highest fire rating for a roof, and it belongs to the whole assembly: the covering, the underlayment beneath it and the deck. Many laminated shingles reach Class A over the right underlayment. Concrete and clay tile and metal are commonly Class A. Wood shake generally is not without special treatment and assemblies.

Because the rating depends on the combination, the scope has to specify it, and the permit application states the roof's fire class. Our roof replacement scopes name the assembly, not just the shingle.

Vents, gutters and edges matter as much as the roof

Most houses in wildfires ignite from wind-blown embers rather than a wall of flame, and embers find openings. Attic vents with fine mesh and baffles keep them out while still passing air; our attic ventilation page covers ember-resistant vents. Gutters full of dry leaves are fuel at the roof edge, so metal mesh guards and a late-summer clean-out help. Open ends of tile at the eaves should be closed with bird stops.

What it costs

For most shingle re-roofs, meeting Class A is a matter of choosing the right underlayment and product rather than a big price change. Hillside homes that need upgraded materials and ember-resistant vents throughout cost more; one Bay Area cost guide puts Class A materials and ember-resistant vents at roughly $1,200 to $2,500 in added material cost. Metal and tile carry their own premiums over shingle, covered in our material comparison.