We seriously looked at a "stick-built" trailer before we bought the Boler
, and I doubt our "fiberglass" unit has any significant advantage in a fire over that "stickie". Both have a fiberglass outer skin (the Boler's is much thicker), foam inside (polystyrene in the stickie sandwich walls, thin soft foam lining the Boler) and lots of wood (inner skin and cabinets of the stickie, all of the cabinets in our Boler
B1700, floor in both). Neither is wood-framed. I would not want to be in either in a fire.
Last year we carried the extinguisher which came with the Boler
(small dry chemical), in a bracket on the wall across from the door. I just bought a larger ABC-rated dry chemical extinguisher to replace it, to be installed by spring. The extinguisher is to handle small fires, such as a kitchen accident, before they get out of hand. If the trailer interior is significantly involved in fire, I'm planning on unhooking the van (if attached), closing the propane
valves, and getting us (including the cat) far away. You couldn't pay me enough to stay in the trailer fighting a major fire with any kind of extinguisher.