Defensible Space — Keeping Your Home on the Range Safe
As wildfires become more frequent and intense, protecting your home is more important than ever – whether you live in town or out on the ranch. “Our fire issue isn’t a fire issue, it’s a home ignition issue,” says Nick Mott, co-author of This Is Wildfire: How to Protect Yourself, Your Home, and Your Community in the Age of Heat.
Research shows that embers and small flames – not massive fire fronts – are the leading cause of home ignitions. These embers can travel more than a mile, landing on roofs, decks, and other flammable materials around homes, sparking dangerous fires.
“Our fire issue isn’t a fire issue, it’s a home ignition issue.
Nick Mott, co-author of This is Wildfire
In the late 1990s, USDA Forest Service fire scientist Jack Cohen developed the Home Ignition Zone (HIZ) concept based on groundbreaking research into how homes ignite due to radiant heat. The HIZ is divided into three zones, each designed to reduce wildfire risk by managing vegetation and materials up to 200 feet from your home. Let’s break it down.
The Three Zones of Defensible Space
1. Immediate Zone (0–5 feet from your home)
- This is the most critical area to address, as embers can easily ignite combustible materials near the home.
- Clean roofs and gutters of leaves, pine needles, and debris.
- Repair loose or missing shingles and install 1/8-inch metal mesh screens over vents.
- Remove flammable materials like firewood, mulch, and dead vegetation from near walls.
- Enclose areas beneath decks and porches with wire mesh to prevent debris buildup.
- Clean roofs and gutters of leaves, pine needles, and debris.
2. Intermediate Zone (5–30 feet from your home)
- Landscaping in this zone should reduce fire intensity and create a buffer between wildland fuels and your home.
- Maintain lawns and grasses at a height of four inches or less.
- Prune trees so branches are 6–10 feet above the ground, preventing fire from climbing.
- Space trees at least 18 feet apart, increasing spacing on slopes.
- Create fuel breaks with driveways, walkways, patios, or gravel areas.
3. Extended Zone (30–100+ feet from your home)
- This zone helps slow the fire and keeps flames on the ground, reducing the chances of crown fires.
- Remove dead trees, shrubs, and accumulations of dry leaves or branches.
- Thin small trees and vegetation between mature trees to prevent fire spread.
- Ensure outbuildings, sheds, and fuel tanks have a defensible space around them.
- Maintain at least 6–12 feet of spacing between tree canopies, depending on distance from the home.
Creating a defensible space isn’t a one-time effort—it requires regular maintenance and adaptation. Continue to search out weak spots in your defensible space. Help your neighbors address theirs if you are able. By taking action now, you can significantly reduce the risk of losing your home or ranch infrastructure to wildfire.
Building Fire-Resilient Homes
- Beyond vegetation management, using fire-resistant building materials and features can improve home survival.
- Choose fire-resistant roofing and siding materials.
- Install ember-resistant vents and keep decks clear of combustible items.
- Ensure emergency responders have clear access to your property.
Creating a defensible space isn’t a one-time effort—it requires regular maintenance and adaptation. Continue to search out weak spots in your defensible space. Help your neighbors address theirs if you are able. By taking action now, you can significantly reduce the risk of losing your home or ranch infrastructure to wildfire.
