Which statement best describes layer protection in WUI structure defense?

• A. Rely on a single measure
• B. Use only defensible space
• C. Use a combination of defensible space, HIZ, and access and materials
• D. Wait for a wildfire to pass and then defend

Answer: (C)

Layer protection means using multiple overlapping defenses so no single measure decides the outcome. In WUI structure defense, the strongest protection comes from integrating three elements: defensible space around the home, management of the Home Ignition Zone (HIZ) with ember-resistant features, and solid access and materials choices for construction. Defensible space reduces fuels and slows flame spread in the immediate surroundings. The HIZ extends protection to the structure itself by removing nearby fuels and adding ember-resistant roofing, vents, and exterior materials, along with appropriate clearances. Access and materials ensure firefighters can reach and defend the home and that the building is built to resist ignition sources, using ignition-resistant siding and roofing, proper window and vent protection, and reliable water or other firefighting resources. Relying on just one measure leaves gaps, and waiting for a wildfire to pass is dangerous. The best approach is to combine defensible space, HIZ practices, and appropriate construction and access features to create multiple, reinforcing layers of defense.