The idea of building houses using massive 3D printers is nothing new…but it hasn’t moved beyond the idea stage…until now.  In China, the WinSun Decoration Design Engineering company has developed a machine to print ten sample structures, each about 200 square meters in size (they didn’t invent the machine, but are the first to really do something on this scale).  The printer extrudes a concrete-like material to build up the walls layer by layer; printing the sloped roof is possible if the house is done in slices that are then rotated up into position (or you can print the walls in their normal orientation, and add a roof using other construction methods).  The video below shows the process well.  I’d be curious in seeing an environmental comparison of this process versus traditional wood frame houses – concrete is not eco-friendly, but it does have the potential to last much longer.