@knewman @jef these are made from either plastic and aluminum, or fiberglass and foam insulation. They are not readily combustible but will catch fire. Though if the aluminum catches fire you got a class D and probly more problems then what the house is built from. They are a compromise between livability and cost which is an important factor to help the most people possible as much as possible. Throw in mailing addresses, rest room access, and free public transit; you have hire-able stability