Homes and buildings have been built in just a few ways for millennia.

Timber-frame, traditional stick frame, brick, stone, and concrete block have long been among the most common building types.

Now, however, several companies and organizations are working out methods to produce buildings using 3D printers. This method is sometimes called “contour casting.”

WinSun Decoration Design Engineering Company recently printed 10 small buildings in about 24 hours at its factory near Shanghai, China. Company president Ma Yihe said he has been working on contour casting for structures for 12 years.

He said the material used is a mixture of ground-up, recycled components, including concrete and construction waste. Not only does this process consume existing waste, it offers the potential to recycle the house in the future by using the material in a new structure.

“With 3D printing, in the future we can build good buildings, with reliable materials, and without waste,” he said. “Waste from demolished buildings, industrial waste, and even mine tailings can be used to build structures with our recycling treatment.”

WinSun’s 10,000 square metre factory, which was also 3D printed, houses the giant 3D printer setup, which measure 32 metres by 10 metres by 6.6 metres. In contour casting, the printer lays down layer after layer of quick-drying, semi-liquid material.

WinSun says it printed the 10 buildings, which are 200 square metres in size, for less than US$5000 each.

Others are working on taking the 3D printer to the job site.

Students at the Center for Rapid Automated Fabrication Technologies (CRAFT) at the University of Southern California and its director, Behrokh Khoshnevis, have been working on projects that use 3D printing technology for emergency housing, space colonies, and low-income housing.

Khoshnevis is a professor of Industrial & Systems Engineering and Civil & Environmental Engineering, and is the director of the Manufacturing Engineering Graduate Program at USC.

The technology appears to have great promise in the developing world, where substandard housing results from poverty, overcrowding, and lack of suitable building materials. CRAFT claims that houses can be “printed” very affordably on site thanks to recycled materials, local materials and the small need for labor. As the CRAFT web site states:

Contour crafting, or 3D printing, has the potential to transform current housing and building norms worldwide. For example, in the developed world, the process could replace older, worn out buildings while converting waste into raw materials. At the same time, if small structures can be built in less than 24 hours, the cost of housing would have to fall dramatically.

If the process can be scaled up rapidly in the next few years, and adapted to create more varied structures such as multi-unit apartments, 3D printing could offer the fastest way to transform the slums of the developing world. Block by block, 3D printing could simultaneously consume waste and produce dwellings and other structures.