Zone 0 Regulations: What California Homeowners Must Do to Comply

California’s Zone 0 regulations set the standard for the first five feet around your home — the ember-resistant zone where combustible material is essentially banned. Created by AB 3074, which amended Public Resources Code 4291, and being finalized by the Board of Forestry and Fire Protection, these rules govern your mulch, fencing, deck, and hardscape in the highest-risk band of defensible space. This is the plain-English compliance guide for what they require, how they are enforced, and how to pass an inspection.

What the Rules Cover

Zone 0 is the 0-to-5-foot band measured outward from any exterior wall, deck, or attached structure. The regulation treats it differently from the rest of your defensible space: instead of “reduce and thin,” the standard is “remove and replace with noncombustible material.”

The requirements apply to homes in the State Responsibility Area and in Local Responsibility Area parcels mapped as Very High Fire Hazard Severity Zone under CAL FIRE’s 2025 maps.

Everything within that five-foot line is in scope — the ground, the fence, the deck, and anything stored or growing there.

The Zone 0 Compliance Checklist

Across the statute and the draft rule, the requirements within the five-foot zone are consistent. Use this as your working checklist.

• Mulch: Remove bark, wood chips, and shredded-rubber mulch. Replace with gravel, decomposed granite, pavers, stone, or bare mineral soil.
• Fencing: No combustible fence or gate attached to the house; the section within five feet must be noncombustible (metal or masonry).
• Stored materials: No firewood, lumber, propane tanks, or combustible furniture against the wall.
• Decks and overhangs: Nothing combustible stored underneath; no vegetation growing under attached decks or stairs.
• Vegetation: Little to no planting; the standard favors a plant-free band, with at most low, well-irrigated, widely spaced plants.
• Roof and gutters: Kept clear of dead leaves and pine needles that catch embers.

Why the five-foot line is drawn where it is

Post-fire studies show most homes ignite from embers and small surface fires immediately adjacent to the structure. The rules exist to make that adjacent surface incombustible, so an ember that lands has nothing to feed on.

How Zone 0 Fits With the 100-Foot Rule

These requirements do not replace the older defensible space law — they sit inside it. PRC 4291 still requires up to 100 feet of managed defensible space across three zones.

• Zone 0: 0–5 feet — ember-resistant, noncombustible.
• Zone 1: 5–30 feet — “lean, clean, and green,” with spacing between plants.
• Zone 2: 30–100 feet — reduced and thinned fuel, mowed grass, limbed-up trees.

Zone 0 is simply the strictest, closest, and most decisive of the three.

The Legal Status of the Zone 0 Regulations

AB 3074 created the mandate in 2020, but directed the Board of Forestry and Fire Protection to write the enforceable rule. That rulemaking is being finalized, and the state accelerated it after the January 2025 Los Angeles fires.

Under the statute’s structure, the standard applies to new construction first and to existing homes roughly one year after adoption. Homeowners have a planning window — but the requirements are not expected to loosen. Related measures such as CBC Chapter 7A and SB 896-era wildfire legislation reinforce the same trajectory.

How the Rules Are Enforced

Enforcement runs through defensible space inspections. CAL FIRE and local fire agencies already inspect properties for PRC 4291 compliance; once adopted, Zone 0 becomes part of that inspection.

An inspector walking your perimeter will look for exactly the items on the checklist above — bark mulch against the wall, a wood fence tied to the siding, firewood stacked under the eave, or shrubs crowding the foundation. Failing an inspection can trigger a correction notice and, if ignored, citations.

The detail inspectors flag most

The combustible fence connecting to the house is the most common and most dangerous violation. Replacing the last five feet with a metal panel or gate — about $40 to $100 per linear foot — resolves it and removes a direct path for fire into your home.

How to Prepare for a Zone 0 Inspection

Passing is straightforward if you walk your own perimeter first with an inspector’s eye. Work methodically around the house and treat every wall the same.

• Stand at each exterior wall and measure five feet out; that is your working zone.
• Clear everything combustible in that band — mulch, plants, firewood, furniture, planters.
• Replace ground cover with gravel, stone, or pavers.
• Swap the fence section that meets the house for noncombustible material.
• Look up: clear the roof and gutters, and clear under any attached deck or stairs.

Document the work with dated photos. If a local program or your insurer asks for proof of mitigation, that record makes the conversation simple.

Common Zone 0 Violations

Most failed inspections come down to the same handful of oversights. Knowing them in advance is the fastest way to comply.

• Bark or wood-chip mulch in foundation beds.
• A wood or vinyl fence bolted directly to the siding.
• Firewood stacked against the wall “just for the season.”
• Wooden raised planter boxes within five feet.
• Vegetation and stored items under an attached deck.
• Climbing vines on walls and eaves.

What Compliance Costs

For a typical single-family lot, expect these ranges when meeting the Zone 0 regulations:

• Hardscape swap (mulch to gravel or pavers) in the 5-foot band: $3 to $8 per square foot.
• Noncombustible fence section or gate at the structure: $40 to $100 per linear foot, or $500 to $2,000 per gate.
• Full Zone 0 retrofit — hardscape, fencing, deck clearance, plant removal: commonly $3,000 to $15,000.

Set against the value of the home, this is inexpensive insurance — and it is one of the mitigation actions California’s wildfire-safety framework recognizes for insurance eligibility and discounts.

Local Rules May Move Faster Than the State

Some jurisdictions in San Diego, Los Angeles, and other high-risk counties are educating homeowners and running their own defensible space programs ahead of statewide enforcement. Your city or fire district may effectively hold you to these standards before the state deadline formally reaches existing homes.

The Cost of Waiting

Some homeowners plan to wait until the standard is formally enforced on existing homes. That is usually the more expensive path.

When a deadline lands, demand for fencing, hardscape, and mitigation crews spikes across every high-risk county at once, and prices rise with it. Acting on your own schedule lets you get competitive bids and phase the work.

There is also the risk you cannot schedule around: fire season does not wait for the rulemaking calendar. A property that meets the Zone 0 standard today is protected during the next wind event whether or not the enforcement date has arrived. The regulation is a floor for safety, not the moment risk begins.

Frequently Asked Questions

Are the Zone 0 regulations law yet?

The mandate is law under AB 3074, but the detailed enforceable rule is being finalized. New construction complies first, existing homes about a year after adoption.

What exactly is banned in Zone 0?

Combustible mulch, wood or vinyl fencing attached to the house, stored firewood and furniture, and vegetation under decks — anything an ember can ignite within five feet of the structure.

Can I have gravel or rock in Zone 0?

Yes. Gravel, decomposed granite, pavers, stone, and bare soil are the preferred noncombustible ground covers for the five-foot zone.

Do the rules apply to renters or only owners?

The obligation falls on the property owner, though tenants can be affected by required changes to landscaping and fencing.

Who inspects for Zone 0 compliance?

CAL FIRE and local fire agencies conduct defensible space inspections; Zone 0 becomes part of that inspection once adopted.

What happens if I fail an inspection?

You typically receive a correction notice with a deadline. Ignoring it can lead to citations and fines under defensible space law.

Do the Zone 0 regulations require me to remove all plants?

The standard strongly favors a plant-free band; a few low, well-watered, spaced plants may be allowed, but shrubs and bark mulch against the wall are not.

How is Zone 0 different from Zones 1 and 2?

Zone 0 (0–5 ft) is noncombustible; Zone 1 (5–30 ft) is spaced and irrigated; Zone 2 (30–100 ft) is thinned fuel. Zone 0 is the strictest.

Where do I find my fire hazard zone?

Check your address against CAL FIRE’s 2025 Fire Hazard Severity Zone maps to confirm whether the rules apply to you.

Next Steps

The Zone 0 regulations reward homeowners who act early: you meet the standard on your own schedule and budget instead of under a correction notice. Start with the checklist above and work outward from the wall.

The single item that fails the most inspections — and creates the clearest path for fire into your home — is a combustible fence or gate attached to the structure. Replacing that five-foot section with noncombustible material is fast and affordable. Check how your property measures against the standard with our wildfire risk assessment tool.

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