Printing Buildings

Most discussion about 3D printers revolve around small items. There has been a lot of talk about printing firearms, hand tools, nuts, bolts, etc. but some people are dreaming bigger:

We have seen huge advancements in 3D printing. We’ve even seen oversized wrenches printed that measure 1.2 meters in length. Now, we can print an entire 2,500 sqft house in 20 hours. In the TED Talk video below, Behrokh Khoshnevis, a professor of Industrial & Systems Engineering at the University of Southern California (USC), demonstrates automated construction, using 3D printers to build an entire house in 20 hours.

In manufacturing we use a process called CAD/CAM (computer-aided design / computer-aided manufacturing). 3D models are designed on a computer and then manufactured using CNC Machines or 3D printers. The design is manufactured into a physical object automatically, with instruction from 3D computer model to physical object without human interface. Automated construction basically scales up this process. The size of the 3D printer is large enough to construct walls by depositing concrete based material layer upon layer to build a wall.

Here's a video giving an overview of the idea and a demonstration of a prototype printer:

I can't even begin to explain how awesome this idea is. Buildings are expensive, which is due in part to the amount of labor needed to go from an empty plot of land to a stable structure that can keep the elements at bay. Being able to erect a house in a mostly automated manner would drastically reduce costs. If the technology became widespread enough it could allow more people to have dwellings both here in the United States and in poorer "third-world" countries. Furthermore, the technology could make houses affordable enough where donations could be used to build more facilities to house the homeless.

This is a technology I really hope takes off.