Prefabricated steel buildings and other cool stuff
All a Quonset hut is made of is mostly corrugated metal and some crossbeams. There are cross beams down at the end that add to the structural integrity, but the corrugated steel really makes these structures sound. So instead of other types of construction that rely on support beams, then siding and sheet rock or big logs or rocks and concrete, a Quonset hut is made of simple materials that come at a reasonable cost. One truck can deliver all of the materials you need, so the transportation cost is lower. The other way it manages to stay affordable is that it does not require a lot of manual labor to assemble.