Homeowner guides

Wildfire defensible space and home hardening: what California requires

What state law requires around a home in a fire hazard area, where Zone 0 stands, what you need when you sell, and the basics of making a house harder to ignite.

Sources checked September 27, 2026. General information, not legal advice.

Who the state rules apply to

Two laws set the same basic rule. Public Resources Code §4291 covers buildings in the State Responsibility Area. Government Code §51182 covers homes in a Very High Fire Hazard Severity Zone inside cities and other local areas. Local agencies can adopt rules “that are more stringent” (§51182), and some here have (examples below).

To find out whether your property is in a fire hazard zone, use your fire agency’s lookup: SLO County Fire’s fire hazard zone page and Santa Barbara County Fire’s defensible space page both link a map.

The 100-foot rule

If the rules apply to you, you must “Maintain defensible space of 100 feet from each side and from the front and rear of the structure, but not beyond the property line” (PRC §4291). The same section also requires you to:

  • “Remove that portion of a tree that extends within 10 feet of the outlet of a chimney or stovepipe.”
  • “Maintain a tree, shrub, or other plant adjacent to or overhanging a building free of dead or dying wood.”
  • “Maintain the roof of a structure free of leaves, needles, or other vegetative materials.”

The zones around the house

The 100 feet is usually described in zones. Santa Barbara County Fire’s local standard, for example, defines:

  • Zone 0: “the five (5) feet immediately surrounding a structure, any outbuildings, attached decks, or stairs,” sometimes called the ember-resistant zone.
  • Zone 1: 5 to 30 feet from the structure.
  • Zone 2: 30 to 100 feet from the structure.

Within the Santa Barbara County Fire District, its Zone 0 rules apply to buildings constructed, or landscapes modified, after July 1, 2024; its Zone 1 and Zone 2 rules apply to all structures (SBC Fire Standard 6). Other agencies use their own distances. The City of Santa Barbara, for example, requires 150 feet in its Extreme Foothill Zone (City of Santa Barbara). Check with the fire agency for your address.

Where the statewide Zone 0 rules stand

State law already calls for an ember-resistant zone within 5 feet of a structure, but says it “shall not take effect for new structures until the board updates the regulations,” and takes effect for existing structures “three years after the effective date for the new structures” (PRC §4291).

The Board of Forestry “adopted the emergency regulations at its regular meeting on August 19, 2026” and planned to submit them to the Office of Administrative Law (Board of Forestry notice). When we checked on September 27, 2026, we could not confirm that they had taken effect. The Board’s summary describes rules such as “Firewood cannot be stored in Zone 0” and limits on fallen leaves, combustible mulch and attached combustible fences, phased in for existing homes over three years (up to five for some items, on a timeline set by the local fire agency). Ask your fire agency whether the rules are in force before planning work around them.

Selling a home in a fire hazard zone

Since July 1, 2021, a seller of a home in a high or very high fire hazard severity zone must give the buyer “documentation stating that the property is in compliance” with the defensible space rules, or the buyer and seller must sign a written agreement for the buyer to get it (Civil Code §1102.19). Santa Barbara County Fire and SLO County Fire explain how to request an inspection.

Home hardening basics

Defensible space is about what’s around the house; hardening is about the house itself.

  • Building code: new buildings in fire hazard areas follow California’s wildland-urban interface building rules. As of January 1, 2026 these moved from Chapter 7A of the Building Code into a new Part 7 of Title 24, the California Wildland-Urban Interface Code (OSFM bulletin 26-004).
  • Vents: embers can get in through attic and crawl space vents. UC ANR suggests you “Retrofit your existing vents with metal mesh (1/8-inch or 1/16-inch screening)” (UC ANR). Local standards can require a specific size, so check with your fire agency first.
  • Roof: the roof and gutters catch embers and debris. For new structures and reroofs in Very High zones, state law generally requires a Class A roof covering; see our guide on roof repair or replacement.
  • Near the walls: the ember-resistant zone ideas above, such as moving firewood and combustible mulch away from the house, are worth considering even before the rules are in force where you live.

Local fire agencies

Sources

  1. Public Resources Code §4291 (defensible space, state areas)
  2. Government Code §51182 (defensible space, local Very High zones)
  3. Civil Code §1102.19 (sale documentation)
  4. Board of Forestry: Notice of Proposed Emergency Action, Zone 0 Defensible Space (August 20, 2026)
  5. OSFM Information Bulletin 26-004 (April 14, 2026)
  6. UC ANR Fire Network: Vents
  7. Santa Barbara County Fire: Defensible Space Program
  8. Santa Barbara County Fire: Development Standard 6, Defensible Space (rev. 06/13/2024)
  9. CAL FIRE San Luis Obispo Unit / SLO County Fire: Defensible Space
  10. CAL FIRE San Luis Obispo Unit / SLO County Fire: Fire Hazard Severity Zones
  11. City of Santa Barbara Fire: Defensible Space Inspections

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