Is there some secret race among Japanese architects to be the mastermind behind the narrowest house in the country? It sure seems like it, given the inexplicable (but undeniably fun to watch) proliferation of skinny houses popping up across the nation's urban areas. YUUA Architects designed this very narrow house, which measures just 1.8 meters (about 6 feet) wide, in notoriously dense Tokyo. The great thing about this house, other than its novel form, is just how livable its interiors seem. No, you're not exactly going to be doing jumping jacks in here, but you'll be able to do all you need to live comfortably. The steel-frame house has a glazed facade, to boot, so light abounds inside and helps make the narrow living room, combined kitchen-dining room and sleeping area feel more spacious than they are, despite gorgeous dark walls and wide-plank timber floors.