Zone Zero Regulations Explained for Altadena | AB 3074, SB 504, AB 1455
The Law · Altadena · LA County

Zone Zero Regulations, Explained for Altadena

Three state laws and one draft regulation create the ember-resistant zone. AB 3074 (2020) wrote the 0–5 ft zone into law, SB 504 (2024) and AB 1455 (2025) pushed implementation forward, and the April 17, 2026 Board of Forestry draft is the current rule text. In Altadena, the Los Angeles County Fire Department is the authority that will enforce it.

Zone Zero Altadena / Regulations

The Statutes

The paper trail behind Zone 0

You do not need to read the statutes. You need to know what each one changed for your parcel.

2020 · Statute

AB 3074: the zone is born

Created the ember-resistant zone: the first 5 feet around structures in Very High Fire Hazard Severity Zones must be free of combustible material. Everything since is implementation.

2024 · Statute

SB 504: implementation ordered

Directed the state to finish the Zone 0 rulemaking and tightened defensible-space requirements, moving the zone from concept toward enforceable regulation.

2025 · Statute

AB 1455: the timeline reset

Passed after the January 2025 fires, it restructured the Board of Forestry's deadline to complete the regulations, setting up adoption expected late 2026.

April 17, 2026 · Draft

The Board of Forestry draft

The current rule text: phased compliance, education-first enforcement, immediate rules for new fences and new construction, and local AHJ discretion on Phase 2.

State floor, county specifics

In Altadena, the county is the law you will actually meet

Sacramento wrote the framework. But the inspector who visits an Altadena parcel works for the Los Angeles County Fire Department, and it is the county that sets the Phase 2 schedule, runs defensible-space inspections, and decides how education-first enforcement works street by street.

Altadena rebuilds also answer to LA County Public Works and Chapter 7A of the building code for the structure itself. Zone Zero extends that logic outdoors: the parcel's first five feet become part of the fire-safety envelope.

How the layers stack in Altadena
State statutes: AB 3074, SB 504, AB 1455 set the floor
Board of Forestry: writes the Zone 0 regulation text
CAL FIRE: maps the Fire Hazard Severity Zones
LA County Fire: enforces, inspects, sets Phase 2 for Altadena
LA County building code (Chapter 7A): governs the rebuild structure itself
Common Questions

Regulation questions, answered

Is Zone Zero law right now in Altadena?

The statute exists, AB 3074 has been law since 2020, but the enforceable regulations are still being finalized. The Board of Forestry's April 17, 2026 draft is the current text, with final adoption expected late 2026. Once adopted, LA County Fire enforces it in Altadena.

Does Zone Zero apply to detached garages and ADUs?

The zone is measured from structures, and Altadena rebuild lots often add ADUs. Expect the 0–5 ft ember-resistant zone to apply around occupied structures per the final regulation text, and verify the treatment of accessory structures with LA County once the county publishes implementation details.

What does education-first enforcement actually mean?

Under the April 2026 draft, the first response to noncompliance is guidance, notices, and time to fix, not fines. In practice, LA County's existing defensible-space inspections would flag Zone 0 issues and give homeowners a correction path before any penalty.

Why did the rules take so long after the Eaton Fire?

AB 3074 passed in 2020, but rulemaking stalled while the science, cost concerns, and vegetation provisions were debated. The January 2025 fires added urgency, and AB 1455 restructured the timeline. The April 2026 draft is the closest the state has come to final text.

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