Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

Question

Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

In: 8443

Answer 1

With a slanted roof, the larger (wider) the building, the taller the roof would have to be. a large building would have a very tall roof. Imagine a walmart with a slanted roof. The roof would be 100 feet tall.

Also, shingles are more expensive than the waterproof membrane they use for a flat roof. If nobody cares what the roof looks like, (or if nobody can see it) a flat roof a much cheaper option.