What is Zone 0, and is it in effect yet?

Where it is set out, and when it takes effect

The ember-resistant zone within 5 feet of a building, counting any attached deck as part of the building, is set out in Public Resources Code §4291, and its details are left to the Board of Forestry and Fire Protection's regulations.

Under that section, the requirement for the zone (“Zone 0”) does not take effect for new buildings until the Board updates its regulations and its guidance document, and it takes effect for existing buildings three years after that.

Sources: California Public Resources Code §4291; Board of Forestry and Fire Protection: Defensible Space Zones

Where the rules stand

The Board adopted emergency Zone 0 rules on August 19, 2026. The Office of Administrative Law lists that filing as withdrawn on September 8, 2026, and on September 24, 2026 the Board's page said it was still working with that office on a final review.

Sources: Board of Forestry and Fire Protection: Notice of Proposed Emergency Action, Zone 0 Defensible Space (August 20, 2026, PDF); Office of Administrative Law: Recent Actions on Emergency Regulations; Board of Forestry and Fire Protection: Defensible Space Zones

As proposed

As proposed, the Zone 0 standards would apply at once to new construction and be phased in over five years for existing buildings.

Source: Board of Forestry and Fire Protection: Zone Zero cover memo, August 2026 (PDF)