What the Standards Require
This table summarizes the requirements for each level. Flame Zone homes must meet everything in the Essential column plus the additional Enhanced items. Not sure which applies to you? Check the zone map.
| Component | Essential Ember Zone | Enhanced Flame Zone |
|---|---|---|
| Roof | Class A fire-rated roof covering, kept clear of debris | Same as Essential |
| Gutters and downspouts | Noncombustible gutters and downspouts (partially addressed) | Noncombustible gutters and downspouts, plus a noncombustible gutter cover |
| Eaves | Not required | Eaves enclosed with noncombustible material |
| Vents | Ember-resistant vents, or 1/8-inch corrosion-resistant metal mesh over vents | Same as Essential |
| Exterior walls | At least 6 inches of noncombustible material at the base of exterior walls, at ground level and above attached decks or patios. Wood siding is otherwise acceptable. | Fully noncombustible wall covering: no exposed wood or foam, including decorative elements |
| Windows and glass | Not required | Two panes, both tempered |
| Exterior doors | Not required | Metal, solid 1¾-inch wood, or 20-minute fire-rated, with a noncombustible threshold |
| Decks, pergolas, and projections | Bottom 6 inches of posts noncombustible; underside enclosed with 1/8-inch metal screening if less than 4 feet above grade. Clear and maintain the underdeck area. Composite decking is allowed. | Fully noncombustible, including deck surface, rails, and steps |
| 0–5 foot zone | Noncombustible zone extending 5 feet around the home and attached combustible decks (details) | Same as Essential |
| Fencing | Replace combustible fences and gates within 5 feet of the home | Also remove back-to-back fencing unless one fence is noncombustible (metal or block) |
| 5–30 foot defensible space | Spaced vegetation, structures, and other fuels; clear debris; remove firewood; careful plant selection and spacing | Same as Essential |
| Detached structures and ADUs | Allowed within 30 feet only with at least 10 feet of spacing from the home and other structures, construction matching the main home, and their own 0–5 foot zone and other mitigations | No detached structures within 30 feet |
What counts as noncombustible?
Noncombustible
- Siding: three-coat stucco, fiber-cement, brick, stone, masonry veneer, metal
- Decks: steel joists, lightweight concrete, tile, stone, pavers, brick, aluminum
- Ground: gravel, river rock, decomposed granite, steppingstones, concrete
Combustible
- Siding: vinyl, wood, engineered wood
- Decks and fences: any wood, including “fire-resistant” wood; composite and vinyl decking
- Ground: wood and rubber mulch, pine needles, grass, and vegetation, even if irrigated
How this compares with the building code
The 2026 California Wildland-Urban Interface (CWUI) code, Chapter 5, sets the minimum legal requirements for building in wildfire-prone areas. It references Class A roofs, ember-resistant vents, the 6-inch vertical clearance, and exterior doors. It only partially addresses gutters, eaves, wall coverings, glass, decks, detached structures, and defensible space, and it does not yet reference the 0–5 foot zone (a Board of Forestry rule is pending).
IBHS Enhanced goes beyond code by eliminating exposed combustible materials such as wood, enclosing eaves, requiring tempered glass in both panes of dual-pane windows, requiring noncombustible decks and pergolas, and requiring the 0–5 foot zone.
Most new homes built to the new L.A. County codes already do most of what certification requires, but not all of it.
Surviving homes may have more to do, such as replacing windows with double-pane, double-tempered glass. Meeting code does not by itself earn certification, so if you are rebuilding, review these standards with your architect and contractor now.
A word about roof sprinklers
According to IBHS, roof sprinklers and other exterior water systems are not a substitute for the passive mitigation that Wildfire Prepared Home requires, mainly because there are currently no test standards to determine their effectiveness, especially in high winds.
Exterior sprinkler systems depend on water supply, power, pumps, generators, plumbing, wind conditions, system design, activation, and maintenance. If any critical part fails during a wildfire, the system may not perform as expected. Many homeowners may reasonably choose to add one, but the IBHS program does not allow roof sprinklers to substitute for other required measures.