A California Board of Forestry and Fire Protection subcommittee released an updated draft of proposed Zone Zero defensible space regulations.
The Board of Forestry and Fire Protection (BOF) developed these standards to protect structures from wildfire embers within the first five feet of a building.
Legislation including Assembly Bill 3074 (2020), Senate Bill 504 (2024), Assembly Bill 1455 (2025), and Governor Gavin Newsom’s Executive Order N-18-25 directed the creation of these rules.
The subcommittee drafted the text based on nearly a dozen public workshops and site visits conducted over the past year.
Board Chair Terry O’Brien said: “This area is the most critical zone for protecting a home, and neighborhoods, during a wildfire.
“We’ve taken a thoughtful, science-based approach to develop proposed standards that will meaningfully reduce risk while still being practical for homeowners.”
The proposed regulations apply to homes within the State Responsibility Area (SRA) and Very High Fire Hazard Severity Zones in Local Responsibility Areas (LRA).
Zone 0 targets the area where research indicates homes are most vulnerable to ignition from wind-driven embers.
Executive Officer Tony Andersen explained: “We’ve heard valuable input and feedback from all corners of the state and have worked hard to draft rule text that threads the needle across a very complex set of mandates, risks, and values.
“This proposal reflects a critical next step in the Board’s process – grounded in science, shaped by communities, and focused on what will actually work on the ground.”
The updated draft consolidates different regional approaches into a single recommendation for subcommittee consideration.
Compliance with the regulation is required for new construction immediately upon adoption.
Existing structures will follow a phased-in implementation approach that focuses on education over a 5-year period.
Phase 1 requires homeowners to remove combustible items such as firewood, mulch, and wood chips within five feet of a structure within three years.
This initial phase also includes cleaning gutters, removing dead vegetation, and trimming trees according to specific safety regulations.
Phase 2 mandates the creation of an under-eave safety zone and the replacement of combustible gates within a five-year timeline.
Local jurisdictions will decide the exact schedule for these Phase 2 requirements, which also include adjustments to sheds and fencing.
The regulation defines a non-combustible immediate safety zone directly next to the home and under the eaves.
This safety zone width varies based on the size of the eave, extending to the drip line or a minimum of one foot where eaves are shallow.
A low-combustibility zone then extends from the safety zone to the outer edge of the five-foot perimeter.
Combustible materials like bark mulch or dead leaves are prohibited within the entire five-foot area, including on roofs.
Well-maintained herbaceous plants and flowers are permitted outside the immediate buffer if they are small, non-woody species like poppies or succulents.
Low ground covers such as moss or creeping thyme and mowed grass are allowed if they meet specific maintenance requirements.
Trees are permitted within the zone if branches remain ten feet from chimneys and five feet above roofs.
Property owners must remove ladder fuels and dead wood, ensuring limbs are cleared from the bottom six feet of large trees.
New combustible fences or gates are prohibited within the zone, though the rule allows for repairs to existing structures.
Any sheds or outbuildings located within five feet of a primary structure must feature non-combustible exterior walls and roofs.
Local fire agencies maintain the authority to implement alternative approaches that achieve equivalent safety outcomes.
The BOF is currently tracking legislative proposals and grants to help communities fund the implementation of these standards.
Once the subcommittee forwards the recommendation, the draft will go before the full Board for final approval.
Zone Zero is the first five feet extending outward from a structure and serves as the primary defense against wind-driven embers.
The California Board of Forestry and Fire Protection (BOF) defines this area as an ember exposure zone where most structural ignitions occur.
This zone encompasses the ground immediately adjacent to the building along with external walls, attached decks, and balconies.
Safety professionals designate this perimeter as an ember-resistant zone because it interrupts the dominant mechanism of structure loss during wildfires.
If combustible material exists within this five-foot space, ignition can occur even without direct flame contact from the main fire front.
The regulations target this area to remove the specific pathways that allow small burning particles to accumulate and build heat against the home.
Zone 0 operates as the final control point within the state’s broader three-zone defensible space framework.
While Zone 1 and Zone 2 focus on reducing flame intensity and slowing fire spread, Zone 0 specifically prevents ignition at the building interface.
The requirements for this zone include the removal of dry leaves, pine needles, and wood-based ground covers like bark mulch.
Firewood stacks and other stored items that are capable of sustained combustion must be excluded from this five-foot perimeter.
Non-combustible materials such as concrete, paving slabs, gravel, and stone are the preferred surfaces for this area.
This transition from traditional vegetation management to ignition control represents a shift in how fire services assess property risk.
Compliance with the zone requires continuous maintenance to ensure that seasonal debris does not restore ignition pathways over time.
The phased-in approach for existing homes allows residents to prioritize the most critical removals before addressing secondary structures like fences.
By establishing a defined barrier, the regulation aims to protect the most vulnerable parts of a building such as windows and eaves.
The BOF indicates that a well-maintained Zone Zero significantly increases the likelihood of a structure surviving an ember storm.
This regulation ensures that fire personnel have a safer environment to defend properties during active wildfire incidents.
