If you're cramped on space but aren't interested in knocking down walls for renovation, the company Magic Box, Inc., may be able to help. With the odd and interesting tag line of "A Box to Explore, A Room to Live," this Japanese company, headed up by Jun Ueno, makes prefabricated houses and extension rooms for homeowners who need some room to grow. It can be used as an additional room, office space, a play room for children, a studio, a guest room, or however you can think to put it to use. Making this prefab structure should take about a month, according to the Magic Box's design team, and another week will be needed for setting it up on your property and establishing the foundation and water and electrical supply. The company has offices in Japan and in California, so if you're in either of those regions you might want to call them up to get more information.