Windows are part of the walls, but they pose their own problems in a wildfire. Most windows are single-pane, standard strength glass. Such windows will not stand much heat before cracking or failing altogether. Similarly, the frames of many windows are wood, aluminum or plastic. These materials, when subjected to high heat, could fail, permitting sparks, embers and hot air to enter the home. Single-pane glass will transmit radiant heat almost as though nothing were there. Radiant heat alone can ignite materials inside the house.

Metal blinds or shutters, or double-paned insulated glass in the windows are alternatives. Commercial and some Topanga home-brew solutions are available, but cost dollars or much time. T-CEP has information on some these if you need it. Essentially, you just want to reduce the flow of heat through the glass into the structure. In an emergency, ordinary aluminum foil taped inside the windows could reflect much of the heat.

Clearly the larger the windows and the less thought given to their vulnerability, the more potential danger there is from them. This is especially significant for homes at the crest of a slope or on mid-slope sites which may have to deal with major heat flows rising to them. The combination-often seen in Topanga-of large wooden decks, large window areas, surrounding trees and deep overhanging eaves, combines heat traps, flammable structures and weak spots where fire could penetrate into the home.