Join me in my love of steel aircraft hangars
It is made up of a bunch of pieces corrugated metal that are bent into arches. There are cross beams down at the end that add to the structural integrity, but the corrugated steel really makes these structures sound. The metal is less costly then other types of material partially because you do not need as much. Needing less materials also means that you do not need to invest as much money into transporting the materials. The other way it manages to stay affordable is that it does not require a lot of manual labor to assemble.