Lots of recycle items, old over the road trailers, reefers are best in my mind, shipping containers, grain bins, seen railroad box cars used in the past, military etc surplus metal buildings, school buses and the list goes on. Adapt, improvise, survive. Biggest problem is neighbors and building codes as they all want you to build a 4,000 sq ft colonial so that the tax revenue and neighbors resale value are optimized.
They should hold up pretty well if they are coated with some anti rust agent, roofing tar, etc... The bins are galvanized and corrugated for strength.
