Cost & Permit Guide
Defensible Space Requirements for Bay Area Homeowners (PRC 4291)
California's PRC 4291 requires 100 feet of defensible space around homes in fire-prone areas, split into three zones: Zone 0 (0–5 ft, ember-resistant), Zone 1 (5–30 ft, lean and green), and Zone 2 (30–100 ft, reduced fuel). For a typical 1-acre Bay Area property, professional clearing runs about $1,000–$4,000 — and many insurers now require it to keep your policy active.
Last updated: June 2026
What are the three defensible-space zones?
The 100-foot requirement isn't one rule — it's three concentric zones, each with a different standard. The closer to the house, the stricter.
PRC 4291 defensible-space zones
| Zone | Distance from home | What's required |
|---|---|---|
| Zone 0 | 0–5 ft | Ember-resistant: no bark mulch, no plants against the house, nothing flammable |
| Zone 1 | 5–30 ft | Lean, clean & green: remove dead plants, trim trees, space shrubs |
| Zone 2 | 30–100 ft | Reduced fuel: mow grass, limb up trees, break up continuous brush |
What does defensible-space work cost?
Pricing depends on how overgrown the property is and how steep it is.
| How it's priced | Typical range |
|---|---|
| Typical 1-acre home | $1,000 – $4,000 |
| Per hour (machine + operator) | $100 – $250 |
| Per acre (brush) | $100 – $500+ |
Why is my insurer asking about defensible space?
After the Tubbs, Glass, and Tunnel fires, California insurers tightened up. Many now require documented 100-foot defensible space as a condition of writing or renewing a policy in the wildland-urban interface — and non-compliance is a common reason for non-renewal. Clearing to PRC 4291 standards is increasingly what keeps a home insurable, not just safer.
What do inspectors look for?
- ▸Dead and dying vegetation removed within 100 ft.
- ▸A clear, ember-resistant 5 ft right against the structure (Zone 0).
- ▸Tree limbs cut back from the roof and chimney, and spaced apart.
- ▸Grass mowed and continuous brush broken up in the outer zone.
FAQ
Common questions
Is 100 feet required everywhere?+
It applies to properties in or near State Responsibility Areas and Very High Fire Hazard Severity Zones — which covers most Bay Area hill and rural properties. Your local fire district can confirm whether your address qualifies.
What is Zone 0?+
Zone 0 is the ember-resistant 0–5 ft immediately around your home — the newest and strictest zone, being enforced in Bay Area hill communities. No bark mulch, woodpiles, or flammable plants in this band.
Get a real number for your property
Ranges are a starting point — tell us about your land and get an actual quote from a local crew.