So, I recently found out about the Paper Museum. As far as I can tell, it's designed for children, but they have so much cool stuff to print out and assemble, like this "Japanese Style Room," complete with rush mats (tatami), floor cushions (zabuton), and other assorted pieces.
All told, there are printable dollhouses, food, vehicles (and a town to put them in!), ornaments, gift boxes, animals, and awesome insects and dinosaur skeletons.Their website is entirely in Japanese, but you can muddle your way around easily enough with their cute, reasonably understandable picture menu. You can also try a version loosely translated into English by Google. The first page, however, is still all in Japanese.