The Zone Zero regulations, translated into plain English

The framework

Three laws, one draft, one local enforcer

AB 3074 (2020) created Zone 0 in statute, using the term "ember-resistant zone." SB 504 (2024) and AB 1455 (2025) refined how it's implemented and funded. The April 17, 2026 Board of Forestry draft is the most current regulatory language, and final regulations are expected in late 2026.

Then it goes local. The state sets the floor; your Authority Having Jurisdiction applies it. In Riverside County that means the Riverside County Fire Department for the San Jacinto mountain communities and contract cities, and the city departments in Hemet, Temecula, and Palm Springs. Local adoption is also why the widespread concern over mature trees and shade matters: local rules may allow well-maintained trees where the state draft has scaled back blanket vegetation restrictions. In the pine-forested high country especially, verify with your own department before removing anything.

In the zone

What Zone 0 restricts in the first five feet

• Combustible fencing and gates attached to or within 5 feet of the structure. This is the immediate-effect item and the most common retrofit. See the fences guide.
• Combustible mulch such as bark and wood chips against the foundation. Hardscape, gravel, and stone are the replacements. See the landscaping guide.
• Woody shrubs and flammable plantings under eaves and windows.
• Stored combustibles: firewood (a real high-country habit worth rehoming beyond 5 feet), lumber, trash bins, and furniture cushions in the ring.
• Attachments matter too: decks, stairs, and trellises within the zone face material requirements. See home hardening.

The science behind the rule comes from IBHS ember research: wind-driven embers, not the flame front, ignite most homes, and they ignite them at the base of the wall, in the fence line, and in the mulch bed. Zone 0 removes the fuel where the embers land.

Questions

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