2017
Santa Rosa Fires
Massive losses prompt research into ember-driven ignition and defensible space.
Official definition, history, and enforcement timeline
“Zone 0 extends 0-5 feet from your home, focusing on intense fuel reduction to protect against ember attacks. The first five feet from your home is the most important. Keeping the area closest to buildings, structures, and decks clear will prevent embers from igniting materials that can spread the fire to your home.”
— California Board of Forestry & Fire Protection
Research from IBHS and CAL FIRE demonstrates that the majority of home ignitions in wildland-urban interface (WUI) fires are caused by wind-driven embers, not direct flame contact. Embers can travel over a mile ahead of the fire front, landing on combustible materials near structures.
Post-fire assessments consistently show that the immediate 0-5 foot perimeter around structures is where ember ignition is most likely and most devastating. Removing fuel sources in this zone dramatically reduces home ignition risk.
Massive losses prompt research into ember-driven ignition and defensible space.
Research into ember attack accelerates. Data gathering intensifies.
Legislature mandates Zone 0 study by Board of Forestry by January 1, 2023.
Board of Forestry continues delayed rulemaking process.
Board of Forestry finalizes Zone 0 regulations and requirements.
Local fire departments begin phased enforcement.
| Zone 0 (0-5 ft) | Zone 1 (5-30 ft) | Zone 2 (30-100 ft) | |
|---|---|---|---|
| Purpose | Stop embers | Slow spread | Reduce fuel |
| Actions | Hardscape + noncombustible | Spacing + pruning | Thinning + debris removal |
| Required by law | Yes (new) | Yes (1965) | Yes (2006) |
| Criticality | ★★★★★ | ★★★★ | ★★★ |
The official definition and requirements list have been established. Non-combustible materials within 5 feet of structures, hardscaping, and fuel removal are confirmed requirements.
Local enforcement rules and specific penalties are still being developed. Check back as enforcement develops in 2026-2027. We’ll update this page.
Rules finalize December 2025, enforcement begins 2026-2027. It’s advisable to begin preparing now.