Zone 0: the 5 ft rule for California homes

Zone 0 is the first 5 ft around a home. It is where wind-blown embers are most likely to land and where a home is most likely to catch. California has asked the Board of Forestry and Fire Protection to write rules for it. This guide covers where those rules stand, what the latest draft would require, and what it means for a new ADU.

What Zone 0 is

State defensible space rules already split the area around a home into zones. Zone 1 runs from 5 to 30 ft and Zone 2 from 30 to 100 ft, with distances set by the local fire agency under state law. Zone 0 is the new, closest zone: the ground right next to the walls, out to 5 ft.

The Board's August 2026 summary says Assembly Bill 3074 (2020), Senate Bill 504 (2024), Assembly Bill 1455 (2025) and Governor Newsom's Executive Order N-18-25 directed it to write Zone 0 rules for certain fire-prone areas. Under the draft, they would cover all property owners in state responsibility areas, and owners in very high fire hazard severity zones in local responsibility areas.

Whether the rules are in effect today

They are not. The Board filed Zone 0 rules with the Office of Administrative Law as an emergency regulation. The office's list of recent actions shows that filing, "Zone 0 Defensible Space," withdrawn on September 8, 2026. No effective date has been set, and nothing in the draft is required yet.

The final text can still change, and so can the dates. Before you rely on anything below, check the Board of Forestry's Zone 0 page at bof.fire.ca.gov or ask CAL FIRE.

What the August 2026 draft would require

The Board's summary of the August 2026 draft splits Zone 0 in two.

• A noncombustible safety zone right next to the home and under the eaves. It is at least 1 ft wide or out to the edge of the eave, whichever is greater. With 12 in eaves it is 12 in wide; with 36 in eaves, 36 in. It also runs 2 ft from windows, glass doors and vents, and 5 ft around attached decks, stairs and pergolas. Nothing grows here.
• A low-combustibility zone from there out to 5 ft.

Within the 5 ft, the draft would require:

• No combustible materials. No bark or other combustible mulch, fallen leaves and needles, wood chips, firewood or stored wood, and nothing that burns on the roof or in the gutters.
• Trees. Existing trees may stay. Branches 10 ft from chimneys and clear of eaves, trimmed 5 ft above the roof, dead wood removed, and lower branches cut from the bottom 6 ft of a large tree or the lower third of a small one, whichever is less. No new trees planted in Zone 0.
• Plants. Outside the safety zone, well-kept herbaceous plants and flowers up to 18 in, low ground covers, lawn mowed to 3 in, and potted plants in noncombustible pots no taller than 1.5 ft.
• Fences and gates. A 5 ft noncombustible section where a fence meets the home, such as a metal gate instead of a wooden one. No new combustible fences or gates in Zone 0; repairs to existing ones are allowed.
• Sheds. Sheds and other outbuildings in Zone 0 have noncombustible exterior roofs and walls.

Local fire agencies could approve other practices that work as well, such as fire-safe building materials or plants suited to the region. The city council or board of supervisors has to approve each variation.

How the phases would work for existing homes

Under the draft, new construction would comply as soon as the rules are adopted. Existing homes would phase in:

1. On the effective date. Remove combustible debris from roofs and gutters, dead tree branches, and branches within 10 ft of chimneys. These match current state law.
2. Phase 1, within 3 years. Remove firewood, dead leaves, mulch and wood chips within 5 ft; remove dead and dying plants; trim trees; and adjust plants to what is allowed.
3. Phase 2, within up to 5 years. Your city or county sets the date. Create the safety zone under the eaves, replace combustible gates, and make any changes to sheds and fences.

The summary says inspections would focus on helping owners find problems and make steady progress.

A new ADU in a very high fire hazard zone

A new ADU is new construction. Once Zone 0 rules take effect, the draft would have it meet them from the start, not on the phased schedule. Plan the first 5 ft around the ADU with the building: gravel or pavers against the walls, no new trees close by, and a noncombustible section where any fence meets it.

The building itself already follows the California Wildland-Urban Interface Code in a fire hazard severity zone. LA County's construction notes list a Class A roof, vents listed to ASTM E2886 or covered with 1/16 to 1/8 in mesh, multi-pane windows with at least one tempered pane, and noncombustible gutters. The notes also say the property has to meet the vegetation management requirements before final approval. For more, see building in a fire zone.

Work you can do now

You don't have to wait for the rules. The Department of Insurance's Safer from Wildfires program already lists a 5 ft ember-resistant zone among the actions that qualify for an insurance discount: clear greenery, swap wood chips for stone or decomposed granite, and replace wood fencing attached to the home with metal. Cleaning the roof and gutters and keeping branches 10 ft from the chimney are already part of state law. See fire-ready work and insurance discounts.

Where to check your property

Whether Zone 0 would cover your home depends on the fire hazard zone and on who is responsible for fire protection there. Run the free fire check for the address. It shows the zone, the fire department that inspects, and the rules that apply today. If you are planning an ADU, check the address too.