The bigger picture

A computer-controlled technique for building houses that uses a nozzle on a moveable gantry to ´print´ layers of concrete on top of each other has the potential to save time and costs, and could be used to colonise other planets, according to its creator. ´Contour crafting´ is the brainchild of Dr Behrokh Khoshnevis, an industrial and systems engineering professor at the University of Southern California, who believes it could reduce the cost of commercial construction projects by around a fifth.