California Public Resources Code 4291 requires anyone who owns a building or structure in a wildfire-prone area of the state to create and maintain at least 100 feet of defensible space around it. That space is divided into three zones, each with its own fuel-reduction standards, and the rules get stricter the closer you get to the walls. The point is to slow an approaching wildfire and give firefighters a survivable area to work in.
Who Has to Comply
PRC 4291 applies to anyone who owns, leases, or operates a building in the State Responsibility Area (SRA), the roughly 31 million acres of privately owned wildland where CAL FIRE handles wildfire protection. A companion statute, Government Code Section 51182, extends nearly identical requirements to properties inside Very High Fire Hazard Severity Zones in Local Responsibility Areas, so cities and counties that run their own fire protection in high-risk zones enforce the same standards.
The duty sits with the property owner, not the tenant. If you rent out a foothill cabin or lease a commercial building surrounded by brush, you are the one on the hook, even though someone else uses the space. The requirement covers every structure on the parcel: the main house, detached garages, sheds, barns, and other accessory buildings.
The Three Defensible Space Zones
The statute originally treated the 100 feet around a structure as a single management area. Legislation passed in 2020 restructured it into three zones with distinct goals. Zone 0 runs from 0 to 5 feet, Zone 1 from 5 to 30 feet, and Zone 2 from 30 to 100 feet. Defensible space extends 100 feet outward from the structure, or to the property line if that is closer, and a local ordinance or site conditions can require more.
Zone 0: The Ember-Resistant Zone (0 to 5 Feet)
Zone 0 is where most structure ignitions begin. Wind-driven embers can travel more than a mile ahead of a wildfire, and anything combustible within five feet of your walls, decks, or eaves is what tends to catch first. The goal is to eliminate anything an ember can light.
Within five feet of the structure, including underneath attached decks, remove all vegetation, living or dead: grass, ground covers, shrubs, and bushes. Wood mulch, bark chips, and synthetic turf are also prohibited here because they can smolder and ignite when embers land on them. Replace ground cover with hardscaping such as gravel, rock, concrete, or pavers. Move firewood stacks, lumber, wicker furniture, and straw mats out of the zone.
Fencing, gates, and trellises that attach to the building should be made from noncombustible material. A wooden fence connected to your house acts as a wick. If replacing an entire fence isn’t practical, the first five feet coming into the structure should at least be metal or another noncombustible material.
Zone 1: Lean, Clean, and Green (5 to 30 Feet)
Zone 1 runs from the edge of Zone 0 out to 30 feet from the structure, or to the property line if closer. Fuel reduction is most intensive here because fire behavior within 30 feet has the greatest influence on whether a structure survives.
Remove all dead or dying plants, branches, weeds, and grass. Keep living vegetation watered and maintained. Cut back tree branches that hang within 10 feet of a chimney or stovepipe outlet. Prune trees so the lowest branches are at least six feet above the ground, which removes the “ladder fuels” that let flame climb from grass into the canopy.
Space tree canopies and shrub groupings apart from one another. On flat ground, neighboring tree canopies should be separated by at least 10 feet, and steeper slopes require greater spacing because fire moves faster uphill. Clear leaves, needles, and other debris from roofs and gutters on a regular schedule; clogged gutters are one of the most common ignition points during ember storms.
Zone 2: Reduced Fuel Zone (30 to 100 Feet)
Zone 2 runs from 30 to 100 feet from the structure, or to the property line. The goal shifts from intensive removal to reducing overall vegetation density so a fire reaching this area burns at lower intensity. You don’t need to strip it bare, but you do need to manage it.
Cut or mow annual grass to a maximum height of four inches. Remove dead and dying shrubs and trees entirely. Maintain horizontal spacing between tree canopies and vertical spacing between shrubs and the lowest tree branches, with more distance required on steeper terrain.
Outbuildings and liquid propane gas (LPG) tanks need extra clearance: 10 feet of bare mineral soil around them, plus another 10 feet free of flammable vegetation beyond that. A propane tank sitting in dry brush is both an ignition hazard and an explosion risk for anyone defending the property.
Keeping the Property Compliant Year-Round
Defensible space is not a one-time project. The statute requires compliance “at all times,” so vegetation growth, seasonal debris, and wind events all matter.
In practice, a thorough clearing in late spring before peak fire season, combined with regular upkeep through fall, keeps most owners compliant. Zone 0 needs attention after every wind event because embers, leaves, and pine needles collect closest to the structure, and gutters and roof valleys fill up faster than most people expect. Zone 1 vegetation work is heaviest in spring and early summer when grass grows quickly. Zone 2 needs less frequent work but shouldn’t be ignored, particularly for dead tree and shrub removal after drought or pest damage.
Inspections and Penalties
CAL FIRE and local fire agencies inspect for defensible space throughout the SRA, usually as part of annual programs that ramp up before fire season. A real estate transaction can also trigger an inspection. Officials evaluate each zone against the applicable standards and document deficiencies on an inspection report.
If the property fails, you receive a notice listing the violations and a deadline to fix them. Owners are generally given 30 days to complete the work and schedule a reinspection.
Fines escalate with repeated violations:
- First violation: an infraction carrying a fine of $100 to $500. If you fix the problem before the court imposes the fine and provide proof, the fine may be reduced to $50.
- Second violation within five years: still an infraction, with a fine range of $250 to $500.
- Third violation within five years: elevated to a misdemeanor with a minimum $500 fine.
After a third violation, CAL FIRE may hire contractors to clear the property and bill you for the cost. The State Fire Marshal can also order vegetation removal and place the expense as a lien against the property, similar to an unpaid tax. That lien follows the parcel through any future sale.
Selling a Property Subject to PRC 4291
If you sell property in a high or very high fire hazard severity zone, California Civil Code Section 1102.19 requires you to give the buyer documentation showing the property complies with PRC 4291 or the applicable local vegetation management ordinance. This applies to sales in both the SRA and the LRA.
If you can’t produce compliance documentation before closing, the law requires a written agreement in which the buyer takes on the obligation to obtain it within one year after escrow closes. In jurisdictions with their own defensible space ordinances, the buyer follows the local ordinance’s timeline instead. The compliance duty transfers rather than disappearing at the sale.
That means a failed defensible space inspection can affect your ability to close. Buyers who discover noncompliance may negotiate a lower price or ask you to complete the work before closing.
How Defensible Space Affects Insurance
Under California’s “Safer from Wildfires” regulatory framework, insurers must factor wildfire mitigation, including defensible space maintenance, into their risk assessments and pricing. Work you’ve done to comply with PRC 4291 and local rules has to be considered when the company calculates your premium and risk score.
You can request your wildfire risk score from your insurer at any time, and the company must explain the factors behind it and how you can bring it down. If you’ve completed mitigation work since your last renewal, you can appeal the score directly to the insurer, and if the appeal is denied, the California Department of Insurance can help. FAIR Plan policyholders, who often sit in the highest-risk areas, are also eligible for mitigation-based discounts.