The first house to be 3D printed on site was built last month in Russia. It took 24 hours, and cost just over $10,000. It looks like this:
Houses have been printed before, but only as components that are then assembled on site. What makes this one different is that the whole thing has been printed in one go, right where it stands. Apis Cor have designed a 3D printer that can be delivered to the site and set up like a crane, and it then prints the building from the inside.
With the main structure complete, a truck with a crane lifts the printer out and takes it away. Those walls can be filled with insulation and the roof and windows are added separately.
It’s highly efficient, and creates no waste. What it does use is energy and a lot of concrete, so there aren’t necessarily environmental benefits. How sustainable it proves will depend on the ‘inks’ that are developed to go in it. There may be social benefits though. A Chinese company is 3D printing houses with a slightly different method, and recently put up 10 in a day for $5,000 each. Imagine how fast you could re-home people after a natural disaster. As the price of the technology comes down, it could allow more people to build their own homes.
Of course, like any automation, there would be casualties too. Bricklayers might want to diversify, for a start.