Wildfire risk across California has escalated dramatically in recent years, and state officials are responding with tighter regulation of how structures and nearby land are developed and maintained — especially in areas designated as State Responsibility Areas (SRA) or Very High Fire Hazard Severity Zones (VHFHSZ). A central piece of this effort is the emerging “Zone 0” requirement: an ember‑resistant defensible space within the first five feet (0–5 ft) of a building’s exterior.
This article breaks down what Zone 0 is, the legal context driving it, the current code direction as of 2026, and what this means for contractors — including fence pros — working in or near wildfire‑prone areas.
What Is “Zone 0”?
“Zone 0” refers to the first five feet horizontally around a structure, including the area around attached decks, stairs, patios, and other projections. This space is increasingly recognized as critically vulnerable to ember ignition — i.e., burning material lofted by wind that lands near a structure and ignites combustible materials.
Zone 0 is being formalized through rulemaking by the California Board of Forestry and Fire Protection under authority granted by Assembly Bill 3074 (2020) and accelerated by Executive Order N‑18‑25 (2025). The goal is to codify an ember‑resistant zone that reduces structure ignitions during wildfires.
Why California Is Adding Zone 0 Rules
Traditional defensible space laws like Public Resources Code § 4291 have long required fuel reduction (clearing flammable vegetation) in zones extending from 5 to 100 feet from a structure. However, decades of wildfire losses showed that wind‑driven embers — which fly ahead of the main fire front — can ignite combustible materials immediately adjacent to walls, decks, and attachments, leading to rapid structure loss.
Zone 0 is intended to close that gap by creating an ember‑resistant zone of the first 5 feet around structures, thereby reducing the risk of ignition from embers that land near walls or on combustible items.
Where Things Stand in 2026
As of early 2026:
Draft Codes and Rulemaking
- The Board of Forestry and Fire Protection has been developing regulations to implement Zone 0 and aims to complete the formal rulemaking process by the end of 2025 under Executive Order N‑18‑25.
- These regulations are expected to be incorporated into statewide defensible space standards and local WUI enforcement.
Important Note: As of early 2026, some regulations are still not fully adopted statewide — local jurisdictions may still be finalizing implementation and enforcement schedules. Always check with local fire authorities before starting work.
Application Timeline
Once the regulations are fully adopted:
- New structures in SRA or VHFHSZ may be required to comply immediately upon construction or permitting.
- Existing structures typically are expected to have a phase‑in period, often three years from adoption, for full compliance with Zone 0 requirements.
This means that new construction in wildfire zones in 2026 must be planned with Zone 0 compliance in mind, and many existing homes will need to start compliance planning during construction of attached elements.
What Zone 0 Requirements Will Look Like
Although final text may vary by jurisdiction and specific code adoption, current guidance being discussed in rulemaking and code proposals includes the following for the 0–5 ft ember‑resistant zone:
Eliminate Combustible Materials
- No combustible vegetation within Zone 0 (e.g., flammable plants and shrubs).
- No wood mulch or bark chip ground cover near structure walls.
- No firewood, lumber, or other stored combustibles in this area.
- No fallen leaves, pine needles, grass, weeds, or dead plant material.
Use Non‑Combustible Hardscape and Materials
- Replace combustible ground cover with gravel, concrete, pavers, decomposed granite (DG), or bare soil.
- Keep attached combustible features, like wooden fence sections connected to the structure, out of Zone 0 or replaced with non‑combustible materials.
Keep the Area Clear of Combustible Items
- Outdoor furniture with combustible components, planters, mats, and other items can act as fuel and are generally prohibited or strongly discouraged in Zone 0.
- Debris that can catch embers (leaves, needles, branches) must be routinely removed.
How This Affects Fence and Gate Work
Fence contractors should consider Zone 0 requirements when:
Installing Fences Close to Structures
If a fence touches or comes within 5 ft of a structure’s exterior wall, deck, or stairs in a WUI area, combustible fencing materials may not be permitted within that ember‑resistant zone once the rules are finalized.
Replacing or Upgrading Features
- Replacing old wood gates or fences in Zone 0 with metal, masonry, or other non‑combustible materials may be required.
- Even on retrofits, clients may need to remove combustible fencing and landscape materials to meet defensible space requirements.
New Construction and Permitting
Builders and fence contractors must coordinate with local fire and planning departments to ensure fence and gate details — especially those within 5 ft of structure walls — comply with ember‑resistant defensible space rules once adopted.
Practical Contractor Tips for 2026
Determine Location and Code Applicability
- Confirm whether the property is in a State Responsibility Area (SRA) or a Very High Fire Hazard Severity Zone using CAL FIRE maps or local fire authorities.
- Ask local building departments whether Zone 0 regulations have been formally adopted or are pending in the jurisdiction where you work.
Choose Ember‑Resistant Materials
- When building fences, gates, or other site elements near structures, use non‑combustible or ignition‑resistant materials (e.g., metal, concrete, stone).
Educate Property Owners
- Advise clients about defensible space requirements, especially Zone 0, including the need to remove combustible landscaping and materials in the 0–5 ft perimeter.
Coordinate with Other Trades
- Landscaping, hardscape, and fire safety contractors may also be involved in Zone 0 compliance — early coordination can prevent rework.
Bottom Line: Why Zone 0 Matters for Fence Contractors
Zone 0 is emerging as a critical wildfire mitigation standard in California’s WUI code framework. For fence contractors:
- Combustible fencing and plantings too close to structures may soon be prohibited in high fire risk areas.
- Material selection and placement decisions must account for ember‑resistant defensible space requirements.
- Understanding local adoption and enforcement timelines is essential — Phase‑in periods will vary by locality and code adoption status.
Planning now for Zone 0 — even during 2026 transition periods — will help you advise clients, avoid rework, and deliver fire‑safer projects in wildfire‑prone regions.