We aren't exactly without walls and a roof. I'd say the walls are well in progress, just as yet incomplete. We have a roof for now. It's worn but sturdy. It's not flash and new but it's standing the test of time given it's age and it's more than keeping the rain out at the moment. I'd even go as...
Builder: "So, I've put down the strongest, most reliable possible foundations imaginable. So far they are passing every possible stress test."
Client: "Couldn't you have put the walls in first?"
Builder: "Erm..."