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

Before the modern rubber membrane flat roof or the asphalt, tarpaper roofs, buildings that would have a flat roof like a factory had “saw tooth roofs, a succession of small sloped roof with vertical glass window walls. This had the advantage of also being able to add skylights to bring light into the space. https://en.wikipedia.org/wiki/Saw-tooth_roof