Not sure if this has been said already, and if so i do apologize. I just tried to get a house together, while building straight onto the foundation. It doesn't quite work because you can't line up the walls correctly, they don't snap into place. Quick tip, build floors on the foundation and then you pretty much got it going. Just built a house in less than a minute this way. Structures/Wood/Floors, trust me. Would upload some screenshots, but the forum is not letting me.