^ Air-filled building? Don't have to be spherical, can be cylindrical or "rectanguloid."
I've often wanted to play around with that idea, wondering how the cost of constant inflation would amortize out over the savings in buulding costs, how to insulate from the weather, strengh of construction in weather (like high winds), entryways, sound insulation between rooms, securty from unauthorized entry...
...internal walls could act as "stays" to hold the external walls in shape, and reduce the pressure required -maybe only 25-40" of water pressure.
Et cetera.
Just playin'.
Might actually be practical for a temporary storage building, though.
Terry, 230RN