Building a Home with Wildfire in Mind

For so  many, the dream of building a log home comes with the idea of situating it high atop a mountain surrounded by trees and breathtaking views.  The reality of it is, however, that this dream comes with an increased exposure to wildfire danger.   There is a lot that can be done in the process of building a home to reduce that danger and increase the chance of a home’s survival.  Things to consider include:  location, building materials, and defensible space.

  1. Location.   When choosing a lot and a building envelope, avoid building on a steep slope.  Fire tends to run uphill very quickly.  Find out which direction the prevailing winds come from during peak fire season.  Possibly situate a driveway on that side of the home to increase defensible space.  Be sure that access roads and driveways are designed to be wide enough for fire trucks and other equipment to be able to pass through.  That would mean a width of at least 10 feet with a 2 foot shoulder on either side.  Trees will need to be trimmed up to 14 feet high.  Designing a circular driveway,  or one with an area where large vehicles can turn around is preferable.  Many fire departments will not attempt to access properties where they may end up trapped.  If a bridge is necessary to access the property, be sure that it is designed to withstand the weight of a firetruck.  If a gate is installed that needs a code to open, it is important to give that code to the local fire department.   It is also important to consider which direction the lot is facing.  Although it is appealing to have a sunny south facing lot, it will also dry out quicker.  A north facing lot will hold moisture much better.   Be sure your address is posted in a very visible spot with large numbers that can be seen even at night.


  1. Building Materials. There is good news for those whose dream home includes log construction.  Full logs are amazingly fire resistant.  They are rated just below concrete and stone.  If constructed well, log homes stand a much better chance of survival in a wildfire than a typical stick frame home.  It is important to choose fire-resistant and non-combustible building materials when designing a home.  Metal roofing is particularly fire resistant and solid core exterior doors are a good choice.  Although very appealing, large plate glass windows are more vulnerable to breaking from the heat than smaller windows.  Double or even triple pane windows are also a good choice.  Consider hardscaped patios over wooden decks.  Building a home puts the homeowner at an advantage as it is often much more expensive and at times impossible to retrofit fire-resistant and non-combustible materials into the design of an existing home.


  1. Defensible Space . Reducing natural and manmade combustible material around a home can slow an approaching wildfire,  allowing firefighters time to defend it.  It can also decrease a fire’s intensity.  For a home situated in the Wildland Urban Interface (WUI) defensible space recommendations have been broken down into three zones.  Zone one is defined as the area 0-30 feet from the house.  It is recommended that all flammable material be removed within that area.  Ideally all trees should be removed, grass should be well irrigated and clipped to no longer than 6 inches, needles and woodchips should be removed.  Woodpiles should not be stored within 30 feet of the home.  If a tree has been retained within zone one, it should be considered part of the structure and the distance of the defensible space should be extended accordingly.   Zone two is defined as that area 30-100 feet from the home.  In zone two, trees should be thinned so that there is at least 10 feet between crowns, ladder fuels should be removed, tree limbs should be removed up to 10 feet from the ground, and again grasses should be kept trimmed.   All dead and diseased  trees should be removed.  Woodpiles should be stored uphill from all structures.   Finally, Zone 3 is defined as the area 100 feet and beyond the home.  It is a transitional area, that depending on the area, may need to be thinned but preserved for wildlife habitat.

Every resident living in wildfire prone areas (WUI) needs to know the risks their properties present.  Local fire departments are a great resource.    They can help residents identify those risks as well as methods of mitigating.  In addition, there are many foresters that will inspect properties and make recommendations with regard to adequate defensible space.  It is important to note, that even if a property meets the recommendations of the local fire department, it may not meet the requirements of all insurance companies.  Therefore, it is important that homeowners consult their insurance agent to be sure they have met all insurability requirements.