The short version

  • Defensible space runs from your walls out to 100 feet, in three zones.
  • Zone 0, the first five feet, matters most.
  • Zone 1 is about spacing and cleanup, Zone 2 about keeping fire on the ground.
  • Many areas require it. Ask your fire department for a free inspection.

What defensible space is

Defensible space is the area around your home that you manage to slow a wildfire down and keep it from reaching the house. It also gives firefighters a safer place to work. Fire agencies divide it into three zones measured out from your walls, out to 100 feet or your property line.

Zone 0: 0 to 5 feet

The ember-resistant zone. Nothing that can burn should be against the house: no bark mulch, dry plants, firewood or wood fencing. Use gravel, pavers or bare soil. This zone has its own detailed guide, including California's new Zone 0 rules.

Zone 1: 5 to 30 feet

The lean, clean and green zone. The goal is to keep fire from building up heat close to the house.

  • Remove dead plants, grass, leaves and pine needles.
  • Keep plants watered and spaced apart, with gaps between shrubs and trees.
  • Trim branches back from the roof and well away from the chimney.
  • Move firewood piles and propane tanks out of this zone where you can.

Zone 2: 30 to 100 feet

The reduced fuel zone. Here the goal is to keep a fire low and on the ground, where it moves slower and burns cooler.

  • Mow grass to about 4 inches or less.
  • Thin dense brush and leave space between shrubs and trees.
  • Remove ladder fuels: low branches and shrubs under trees that let fire climb into the canopy. Fire agencies commonly recommend pruning trees up to about 6 feet off the ground.
  • Clear leaf litter and fallen branches, but you can leave the ground mostly covered to prevent erosion.
On a slope? Fire moves faster uphill, so homes on or above a slope usually need defensible space that extends farther downhill. Check with your local fire agency.

Is defensible space required?

In many areas, yes. In California, homes in State Responsibility Areas and in local Very High Fire Hazard Severity Zones must maintain defensible space, and many cities and counties set their own rules and inspect for them. Your local fire department can tell you what applies to your property, and many offer free defensible space inspections.

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Sources

  1. CAL FIRE: Ready for Wildfire
  2. Cal OES: Defensible space, improve your home's chance of surviving a wildfire
  3. Insurance Institute for Business & Home Safety (IBHS): Wildfire research
  4. Best Best & Krieger: California Board of Forestry adopts emergency Zone 0 regulations (Sept 2026)

This guide is general information, not professional advice. Building codes and defensible space rules vary by state, county and fire district. Your local fire department or a qualified contractor can tell you what applies to your home. No home is fireproof. Read our full disclaimer.