How homes burn
Home and building loss during wildfires occur as a result of some part of the building igniting from one or more of the three basic wildfire exposures: 1) direct flame contact, 2) embers, 3) radiant heat.
Embers cause the majority of wildfire home ignition by directly igniting your home or igniting vegetation or materials on or near your home that results in flames touching your house or a high heat (radiant heat) exposure that may break glass in a window. Should embers land on or near your house, they accumulate (like hail or snow) and can easily ignite the plants and mulch near your home, dry leaves, or lawn furniture. They also land on the roof, deck, or porch and, depending on the condition of each, they may find a gap to enter the house or catch accumulated dry leaves on fire. Embers can also enter the home or attic through a vent or open window. When embers enter the home or attic, they can easily ignite the contents of the house, and the home will burn seemingly from the inside out. When ember enter the house directly, there is often little damage to the surrounding vegetation, and many are left puzzled as to what caused the home to burn, as shown in the picture below.