Everything California homeowners need to know about fire-aware fencing and defensible space planning.
Defensible space
A side view from the wall outward. Zone 0 is only the first 5 feet — see how small that is against the full 100 feet.
The 0–5 ft Zone 0 boundary in CAL FIRE defensible space guidance — where near-structure material choices matter most.
The lean, clean and green band of the CAL FIRE defensible-space model.
The outer reduced-fuel band of the CAL FIRE defensible-space model.
Resource Library
Expert resources to help you make informed decisions about fire-resistant fencing
Compliance Guide
Local ember-resistant guidance is evolving. Learn how near-structure material choices can help and how to prepare.
Financial Guide
Learn how fire hardening may affect coverage considerations. Discounts and eligibility vary by insurer and policy.
Technical Reference
Complete guide to ASTM E84 flame spread index, E136 non-combustibility, and what Class A, B, and C ratings mean for local requirements.
Verified Data
Counts pulled from CAL FIRE DINS and state guidance
DINS inspections include structures within 100 meters of the fire perimeter
Source: CAL FIRE DINS
DINS counts reflect inspected structures within or near fire perimeters and may undercount total losses.
Official Resources
Authoritative sources for California wildfire regulations
CAL FIRE
Look up your property's official fire hazard zone designation
California Legislature
Full text of California's Defensible Space law
Ready for Wildfire
CAL FIRE's official homeowner guide to creating defensible space
ASTM International
Official standard for surface burning characteristics testing
CA Building Standards
Ignition-resistant construction standards for wildfire zones. The CWUIC took effect Jan 1, 2026; it absorbed the provisions formerly in CBC Chapter 7A.
FEMA
Federal assistance programs for wildfire victims
CAL FIRE dataset notes SRA FHSZ effective Apr 1, 2024 and LRA recommendations from 2007-2011 (source).
Local Regulatory Status
Where state and local Zone 0 rules stand as of July 2026 — and what still needs confirming with your AHJ.
Yes — the City of San Diego has already adopted Zone 0, ahead of the state. The city's requirement lives in San Diego Municipal Code (SDMC) §512.0604, the San Diego Wildland Urban Interface (SDWUI) Code. It applies to structures in a Very High Fire Hazard Severity Zone within the City of San Diego and took effect for new structures on February 28, 2026, and applies to existing structures beginning February 28, 2027 (subject to change at the discretion of the Fire Code Official).
The statewide Zone 0 rule is different: the California Board of Forestry released an updated draft on April 17, 2026 (workshop April 23, 2026) and it is still a draft, not final law — the original December 31, 2025 deadline passed without adoption. That draft traces to AB 3074 (2020) and PRC §4291, and its fence and gate language is draft §1298.04(b)(8)–(9).
San Diego's adopted rule includes specific exceptions. Existing vinyl fencing may be allowed within 5 feet if it runs parallel to the wall, sits no less than 4 feet from the structure, is kept clear of debris, and has no vegetation between the fence and the structure. New parallel wood fencing is permitted only if it is Fire Retardant Treated Wood (FRTW), meets the vinyl conditions, and is on the California OSFM Wildland Urban Interface (WUI) Products Handbook and approved for exterior use. Your insurer or the IBHS may not allow vinyl or FRTW within 5 feet even where code does.
| Rule | Status | Key dates |
|---|---|---|
| City of San Diego — SDMC §512.0604 (SDWUI Code) | Adopted | New: Feb 28, 2026 · Existing: Feb 28, 2027 |
| Statewide — Board of Forestry (PRC §4291 / AB 3074) | Draft (April 2026) | Not yet final; comment period open |
Sources: City of San Diego Zone 0 Guidelines for Existing Structures (rev. 4/22/2026); California Board of Forestry Zone 0 draft rule text (April 2026). Confirm current status with your AHJ before final design decisions.
FAQ
Defensible space is the buffer zone around a structure where vegetation and combustible materials are managed to slow fire spread. Requirements vary by jurisdiction — check your local AHJ for specifics.
Wood fencing is combustible and can carry fire from vegetation to structures. Vinyl melts and can produce toxic fumes. Non-combustible options include aluminum, steel, gabion, and CMU block walls.
Check your local fire hazard severity zone map through CAL FIRE or your city planning department. Requirements vary by specific zone designation and jurisdiction.
Yes. The City of San Diego adopted Zone 0 through San Diego Municipal Code (SDMC) §512.0604, the San Diego Wildland Urban Interface (SDWUI) Code, effective for new structures on February 28, 2026 and for existing structures beginning February 28, 2027. The statewide Board of Forestry Zone 0 rule remains a draft (April 2026) and is not yet final law. Confirm current requirements with your AHJ.
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