Zone Zero Regulations Explained | AB 3074 & the 2026 Draft

The framework

Three laws, one draft, and your 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, and this county goes local more ways than any other. The San Bernardino County Fire Protection District, having absorbed the city of San Bernardino's department in 2016 and Crestline's district in 2015, adopted the new hazard maps by Ordinance No. 4489 on June 10, 2025. CAL FIRE enforces in its contract cities of Highland and Yucaipa; independent departments in Running Springs, Big Bear, Redlands, and Rancho Cucamonga adopt and apply their own. On vegetation, the state draft scaled back blanket tree restrictions after widespread public concern, and local rules may allow well-maintained trees; in forested mountain communities especially, verify with your own authority before removing anything.

Zone 0 is the first 5 feet out from every wall, deck, and attached structure. Under the April 2026 Board of Forestry draft, this ring must be kept free of combustible material.

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, lumber, trash bins, and furniture cushions in the ring. In mountain communities, the winter woodpile against the wall is the classic violation.
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, and this county supplied one of its defining case studies: post-fire analysis of the 2007 Grass Valley Fire found most of the 174 destroyed homes ignited from wind-driven embers or from house-to-house spread rather than the flame front itself. Zone 0 exists to break exactly that chain.

Questions

Quick answers

What laws actually create Zone Zero?

AB 3074 (2020) created the ember-resistant zone requirement in state law. SB 504 (2024) and AB 1455 (2025) refined the framework, and the Board of Forestry's April 17, 2026 draft is the most current regulatory text. Final regulations are expected in late 2026.

Is Zone 0 the same thing as defensible space?

Zone 0 is the newest and strictest part of defensible space. California already required Zones 1 and 2 (5 to 30 feet, and 30 to 100 feet). Zone Zero adds the 0 to 5 foot ember-resistant ring, the ground the Grass Valley Fire proved decisive when embers, not flames, took most of the 174 homes lost near Lake Arrowhead.

What happens if I don't comply?

Under the April 2026 draft, enforcement is education-first: your fire authority inspects, notifies, and works with you on corrections before penalties come into play.

Find out what your property needs

A free assessment tells you exactly which Zone Zero requirements apply to your parcel, what your local fire authority will look for, and what to fix first. 100% free, no obligation.

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