Shadow banks grew to account for a fifth of all new credit last year, and became the largest source of funding for real estate thanks to loan growth of more than

What happened to Acasa (house-printing with 3D printers)?

According to the following ebook, yes possible and being done already.

3D   Printing: The Next Technology Gold Rush – Future Factories and How to   Capitalize on Distributed Manufacturing: Christopher D. Winnan

Not everybody is printing at the smaller scales. Enrico Dini for example, is using his prototype D-Shape printer to create buildings made of stone and eventually, moon dust. Dini claims the printer is four times faster than conventional building methods, costs one-third to one-half the price of Portland cement and creates very little waste, so it’s better for the environment. The printing process starts with a thin layer of sand. The printer then sprays the sand with magnesium-based glue from hundreds of nozzles, which binds the sand into rock. That rock is then built up layer by layer, eventually taking shape of whatever object it is destined to become, be it a curvy Roger Dean inspired sci-fi dwelling or an entire gothic cathedral.

Although it is still in its early stages, the IAAC Stone Spray Robot shows great potential for 3D printing ecologically friendly structures. The Institute for Advanced Architecture of Catalonia, a research and education centre in Spain developed this robot, similar to Dini’s. Dedicated to the development of sustainable architecture, they hope to “push further the boundaries of digital manufacturing and explore the possibilities of on-site fabrication machines.” The robotic device blends soil sourced on-site with a binder (which is composed of LEED-Certified components), and then sprays the mixture onto a surface. The soil solidifies as the machine works, which allows it to create sculptural forms.  The robot is computer controlled and, unlike other 3D printers, the device runs on solar power.
Inventor and USC engineering professor Behrokh Khoshnevis has developed a contour crafting machine which will allow him to “print” a house out of concrete in twenty-four hours. This is really a 3D printer on steroids, with a gantry crane and a computer-guided cement nozzle on rails attached to it. The USC engineering professor was inspired to build this machine after witnessing the devastation of an earthquake that destroyed the city of Bam, in his native Iran. A typical American house takes at least six months to complete, generating about four tons of waste. It’s believed the contour crafter will be able to erect most structures in about a day, generating far less waste in the process.

Furthermore, by automating the process, architects are free to create some pretty wild designs—curved walls are just as easy to create as flat ones and structurally just as sound. The professor explained the process in a speech at the TEDx conference, which you can watch. (Start at 4:30 to see the animation demo.) In the video, the professor demonstrates how the machine lays down a concrete foundation, puts up walls, even inserts wiring and plumbing, and eventually constructs an entire building. Khoshnevis believes that the contour crafter will ultimately be able to create structures using adobe, mud and straw dried by the sun rather than cement.

NASA recently awarded a team led by Khoshnevis $100,000 to test the concept of 3D printing structures on the moon, including landing pads, roads, shade walls, and dust barriers. In the lunar project, a mixture of lunar regolith (moon dust), water, and cement (made from lunar rock with high calcium) would be used to create walls and other structures, made out of ‘mooncrete.’