So you are having a kid and the house is too small. Or mom is moving home and you need another room. So why do people have to move under such circumstances? When your hard drive is full you can plug in another, because they are all designed to be modular and interchangeable. Why shouldn't houses work that way?
Archigram imagined Plug-in Cities; now Samanta Snidaro, Andrea Fino and Barbara Giroldi of Sand and Birch Design have imagined OFT, a home that " is characterized by spaces adaptable to changeable necessities." We imagine that when one's needs change you can go to the Room Depot and order one up as required, and when the kid or mom moves on, sell it back. Maybe you can lease or rent them for as long as you need them. Great idea from Sand And Birch, via ::Trendhunter and ::Shedworking