[jwmerrill]

An ideal structure should minimize convection, but rooms for people really can't be allowed to undergo large changes in temperature without exchanging air with the outside environment, because that would imply a large change in pressure.

A 10 percent increase over atmospheric pressure might not seem like that much, but it's enough to notice, and would probably be uncomfortable. It's like being under 1 meter of water. It's also enough to break large windows.

[mikeash]

I don't think comfort would be much of an issue given a slow adjustment period, but structurally it would be ludicrous. You'd be unable to open or close doors. Your walls would have to be built a hundred times stronger than the walls of a normal house. Any breach in the pressure envelope would be a miniature version of Aloha Airlines 243.

This is, by the way, why hard drives have filtered air holes rather than being completely sealed.