Even the non-metal roofs have changed. The shape used to be 2-plane, like a book opened face-down, with a spine running from one end to the other. This made two walls of the house pentagonal. Those pentagonal walls typically had the upper portion just sitting there, barely attached. Now the building codes require internal diagonal bracing for that portion, if it even exists. Insurance companies charge more if it exists, so most roofs are more pyramid-like, composed of 4 planes, with the edge of the roof being the same height from the ground all around the house.
Yes. Because some people built poor-quality gable roofs, we all pay more for insurance if we have them. Never mind that the pentagonal walls could be made of steel or poured concrete. Insurance companies just don't want that type of roof.
