Unfortunately this is a incredibly bad take. Anyone can see in the sample images on this page that great care was taken to separate every element of house construction to prioritize ease of use. I even labeled each layer of the house, from foundation to rooftops. I am baffled that you would have so much trouble, and insulted that you would blame me for your difficulties. Perhaps if you came here with a better attitude, friendly assistance could be provided.
Re-reading your comment, I'm struck by the thought that maybe you don't know how tilesets work? Individual tiles can be reused infinitely to make something as tall or wide as you want it to be. The "prebuilt roofs" as you call them, are not prefabs for you to drop into a map, they're a collection of all the tiles you need to construct a rooftop. Repeat the middle straight or diagonal tiles to make your rooftops as big as you need them for your house. And please ask for help before you make obviously false harmful accusations.