The “home ignition zone” encompasses the house itself and everything up to 100 to 200 feet around it. Radiant heat from a severe wildfire can ignite a house from up to 100 feet away, and if there’s enough combustible material in the way, the flames themselves can quickly travel that distance. So if you happen to live in a wildfire-prone area, safeguarding just your home and the five feet surrounding it leaves significant risk on the table.
The area between 30 and 100 feet of a home is a property’s front-line defense against a wildfire. The principle guiding your preparation in this zone should be to create a “defensible space” that can prevent flames from approaching your home, and give firefighters a safe place to combat the blaze. Cal Fire and NFPA have great resources that outline the creation of a defensible space. For instance, once you remove fuel sources from the area immediately surrounding the house, the area between 30 and 100 feet out should be maintained as a “reduced fuel zone.” In this zone, plants should be spaced out, low-hanging tree branches should be pruned, and all vegetation should be watered regularly.
Steinberg notes that some homeowners go overboard when creating a defensible space by clearing the area surrounding their home of all vegetation. It seems counterintuitive, but well-spaced plant life can actually block wind-blown embers from reaching your home. A defensible space completely devoid of vegetation creates a “bowling alley” for embers.