Defensible space is the managed buffer around a home that slows or stops a wildfire and gives the structure — and firefighters — a fighting chance. It is organized into zones: the 0–5 ft noncombustible Zone 0, the 5–30 ft Zone 1, and the extended Zone 2.
Blaze Blocker assesses, establishes, and documents these zones to align with Colorado requirements and the IBHS standard. Documentation is increasingly requested by insurers in high-risk areas.
How the zones work
The single most important zone is the first five feet around the home (Zone 0). Embers collect against the foundation, in mulch beds, and under decks; keeping this band noncombustible removes the most common ignition path.
Zones 1 and 2 manage vegetation density, spacing, and ladder fuels further out so fire can't climb from the ground into tree canopies and race toward the house.
Understanding the home ignition zones (Zones 1–3)
Defensible space is organized into concentric zones measured outward from your home. Each zone has a different goal — together they slow a fire’s approach and rob it of fuel before it can reach the structure. Note: some Colorado guidance labels the innermost 0–5 ft band “Zone 0”; the diagram below uses the Home Ignition Zone naming, where that same critical area is Zone 1.
Zone 1 — Immediate Zone (0–5 feet)
The most critical zone. Embers collect against foundations, in mulch beds, and under decks, so this band should be kept noncombustible: remove bark mulch, firewood, and flammable plants against the walls, keep the roof and gutters clear of debris, screen vents, and use noncombustible materials right up against the home. Hardening here delivers the biggest risk reduction per dollar.
Zone 2 — Intermediate Zone (5–30 feet)
Here the goal is to break up the continuity of fuels so fire can’t move easily toward the house. Mow grass to a maximum height of about four inches, space shrubs and tree canopies apart, remove ladder fuels beneath trees, and create fuel breaks with driveways, walkways, and gravel.
Zone 3 — Extended Zone (30–100 feet)
The outermost zone reduces the overall fuel load and interrupts a fire’s path before it gains momentum. Thin coniferous trees, maintain spacing between canopies, remove ladder fuels, and keep the area around outbuildings and propane tanks clear. On sloped lots this zone may extend further, since fire moves faster uphill.
What defensible space management includes
- Zone 0 (0–5 ft) — Replace combustible mulch and plantings against the home with noncombustible ground cover; clear under decks.
- Zone 1 (5–30 ft) — Thin and space vegetation, remove ladder fuels, and keep the area lean, clean, and green.
- Zone 2 (extended) — Reduce fuel continuity so fire can't build momentum approaching the home.
- Documentation — A written record of established zones for your county and insurer.
All materials and installation methods meet the Colorado Wildfire Resiliency Code (CWRC). We document completed work so your insurer can use it for premium review, and align every project with the IBHS Wildfire Prepared Home™ standard.
Compliance and insurance
Many Colorado counties and the state require defensible space in mapped wildfire hazard areas, and insurers increasingly ask for proof of mitigation. We establish the zones and give you the documentation to satisfy both.
Defensible space works best alongside structural hardening — a hardened home in a managed landscape is dramatically more survivable than either alone.
Common Questions
Is defensible space required by law in Colorado?
What is Zone 0 and why does it matter most?
Do you provide documentation for my insurer?
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