Remember the huge CNC we showed you in June? That one was made for milling out enormous wooden molds; but Behrokh Khoshnevis is working on a gargantuan 3D printer that can print out entire houses.
Khoshnevis is a professor of Industrial & Systems Engineering at the University of Southern California, and his system, Contour Crafting, calls for a moveable gantry whose rails are riding on ground presumably leveled the old-fashioned way, by a construction crew. Concrete houses can then be built up layer by layer, just like on a MakerBot, with spaces left empty to have plumbing and electrical modules inserted within them.
The original idea was to come up with a quick, inexpensive method of construction for disaster relief, but it's easy to see how this could translate to first-world communities. The huge advantage of 3D-printing a house is that you no longer need hew to rectilinear construction methods. Our houses and apartment buildings are largely right angles because they're made out of dimensional lumber, Glulam beams, bricks, cinder blocks, I-beams, et cetera; but as Khoshnevis points out in his TED talk, below, with 3D printing you can take advantage of complex—and beautiful—geometry.
There are a couple more surprises in the video about how this system would be both faster than traditional construction and produce less waste, but I won't spoil them for you. (Check out the wall's serpentine interior construction, though.)