A Country Home's Defensible Space

Part of your defensible space is your home and buildings themselves. If you are building a new home, either stick-built or manufactured, review all plans and insist on fire-resistive material (Building Code Class C or better) for construction. If you have an existing home or other building, I certainly wouldn't advocate major rebuilding to include fire-resistive material, but at least inspect so you'll know your vulnerability to wildfires. If remodeling, always stick to local building codes and regulations and use the most fire safe materials and methods available. When its time for a new roof, use fire-resistive shingles, not wood or shake shingles. Some localities actually have regulations against using shake shingles on roofs.

Before building your defensible space, it's probably helpful to sketch out a plot map of your property with your home, primary buildings and useful landmarks included. Remember to include shops, garages, barns, storage sheds or other valued structures in your planning. It's important to remember that the distances and dimensions on this page are guidelines. To be effective, your defensible space need not be the exact dimensions, but should be within a foot or two of the measurements. Use your common sense and take the terrain of your property into consideration. If your home is on near-level ground, distances may be a little shorter. The steeper the slope away from a structure, the easier it is for a wildfire to burn toward it, so lengthen measurements a little. If your terrain slopes down to your buildings, you probably should worry more about flooding than wildfires. Set a scale for your plot map sketch, and draw buildings and landmarks that you will recognize when you start construction. Now draw rough perimeter lines around your house and other protected buildings at 15', 75' and 125' (or property lines). These perimeter lines represent zones 1 through 3 and indicate the level of effort required for each one. Starting at structures, zone 1 requires the most attention, and zone 3 the least. The areas where the perimeter lines intersect are overlapping common areas and are a section of the defensible space. Use the following diagram as a guideline. Don't worry too much about your artistic abilities as you are the only one who needs to interpret it.

Now, roll-up your sleeves, gather your tools and grab your plot map sketch. You're ready to construct a wildfire defensible space around your country home.

Zone 1 (Building perimeter-15 feet)

Before you start cuttin', hackin', mowin' or diggin', take a moment or two, grab a cup of coffee or cold beer, and survey your property. If you're like me, and proud of your country home's appearance, you probably already have at least a good start on your defensible space. Attractive landscaping is usually maintained and irrigated, so it won't burn too easily. Start by measuring your space out from each building's eve drip-line (or exterior wall if you want) to a known landmark or set a stake. Take a look at these spaces to see what you actually have to accomplish.

Defensible space is defined as an area around structures where fuels and vegetation are treated, cleared or reduced to slow the spread of wildfire towards the structure. It also reduces the chance of a structure fire moving from the building to the surrounding wildlands or forests. As you work on your buffer zone, remember that even the smallest steps in right direction will help. Also remember that a raging wildfire will burn in the path of least resistance and find the weakest link in any defense.

Direct your initial attention to the area 3'-5' from buildings. Remove any combustible material such as firewood or used lumber piles (my personal bad habit) next to any structures. If plants, shrubs or grass occupy this initial area, try to use fire wise plants (check with the local nursery) and always prune and maintain them. Always irrigate any vegetation in this area. As an alternative, especially if you're not fond of yardwork or gardening, use non-flammable ground cover such as decorative rocks. I recommend no trees in this initial 3'-5' area, but you must have trees here, trim branches well away from structures. Keep in mind that defensible space is both horizontal and vertical up to vegetation crown, which are the widest and lowest branches of trees. Trim trees in any zone up 8'-10' from ground to eliminate ladder fuels. Ladder fuels refers to the ease for a wildfire to burn through ground cover such as dry grass, and ignite lower branches on trees.

A defensive space provides the most resistance to fire by breaking up continuity of fuel in its path. High continuity or heavier fuels such as trees or bushes are most hazardous, so should receive the most attention. Grasses are lighter in continuity, so less hazardous, but should be irrigated and cut in any zone.

Zone 2 (75-125 feet)

Defensible space in zones 2 and 3 provides room that is not directly on your home and structures for firefighters to work in the event of wildfire. In zone 2, remove any dead material such as fallen trees or firewood cutting debris. Many people living in the country, myself included, like to pile limbs on our property to provide wildlife habitat for birds and small animals. Wildlife only require one or two wildlife habitat areas per acre, and be sure to trim grass or any other combustible material well away from these areas. In zone 2, cut grass and trim trees and bushes or remove and turn dirt over or disc. Any trees or bushes in this area should be thinned to maintain 10' between tree crowns. Trim trees up from the ground to eliminate the ladder fuels. This area is where propane tanks should be located, at least 30' from structures, and preferably on the same level. If your tank is already closer to structures, think about relocating it, or at least make sure all combustible material is cleared away from it. As always, use your common sense here, and try to visualize a wildfire burning through this area. Does it have enough fuel to maintain or build its momentum?

Zone 3 (125 feet-property line)

This zone is farthest from buildings, and should stretch to your property lines or what is sensible to provide working room for firefighters. Gradually transition from zone 3 to zone 2 in this area.

You're just about done for this year. 'Time to grab another cup of joe or a cold one, and review your accomplishments. The objective you want to see for your efforts is an adequate fire safety zone around your country home. Some added benefits could be more optimum recreational opportunities, enhanced landscape aesthetics and healthy and vigorous vegetation. Your area could also be a barrier for wind, noise, dust or visual intrusions. Most of all, you now have a defensible space to better protect your country home.

Your safety zones will need regular maintenance, in the same manner that you take care of your landscaping. Here is an annual defensible space checklist to help you maintain the area:

• Trees and shrubs are properly thinned and pruned.
• Debris from thinning is disposed of.
• Roof and gutters clear of debris.
• Branches overhanging roof chimney are removed.
• Chimney screens in place and in good condition.
• Grass and weeds mowed regularly.
• Outdoor water supplies including hoses and nozzles available to reach all parts of the house.
• Fire extinguishers checked and in good condition.
• Driveway wide/clear enough for emergency equipment
• Road signs and name and house number posted and visible.
• Rakes, hoes, axes and shovels easily accessible.
• Trash and debris removed from defensible space.

Some other ideas to kick around as you think about protecting your country home from wildfires are developing a Fire Evacuation Plan and a fire safety checklist for inside the home. Your Fire Evacuation Plan should include escape routes and meeting points after evacuation. Practice family fire drills and ensure your fire evacuation plan and all details are known and understood by all family members. A checklist for fire safety needs inside the home or other structures is probably available from your local fire department.

Thanks to Creating Wildfire-Defensible Zones by F.C. Dennis for research and an invaluable reference for this page on defensible space.

For more on wildfire protection...

Modoc Country Living - Wildfire Protection

Return to Home Page