Exterior, Cabin Building Type, Metal Siding Material, Shed RoofLine, Prefab Building Type, and Metal Roof Material The Outward Bound cabins' steel frames lift the structures above a three-foot snowpack while supporting corrugated-steel "snow roofs."  Photo 64 of 101 in 101 Best Modern Cabins from Tiny Prefab Cabins Upgrade a Rugged Camping Site in Colorado