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

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.