Defensible space
Defensible space is the treated area around a building, managed so that an approaching fire loses intensity and firefighters have somewhere safe to stand. California law requires it in State Responsibility Areas, and it is split into zones by distance from the structure.
The most consequential is the closest one. Zone 0, the first five feet, is the ember-resistant zone: no bark mulch, no shrubs against the wall, nothing combustible stored under the deck. Most homes lost in a wildfire are lost to embers landing in exactly this band, not to a wall of flame.
Beyond that, Zone 1 runs to 30 feet and Zone 2 to 100 feet or the property line, each with its own clearance expectations for spacing, dead fuel and overhanging branches.
Defensible space is inspected by fire agencies in many areas, and evidence of it — dated photographs, a clearance notice — is among the more straightforward things to put in front of an underwriter.
Related terms
- Fire Hazard Severity Zone (FHSZ) — CAL FIRE's official wildfire hazard rating for a location: Moderate, High or Very High.
- Safer from Wildfires — The California regulation listing the mitigation measures insurers must recognise.