Chinese companies have been known to build major real-estate projects very quickly. Now, one company is taking it to a new extreme.

Suzhou-based construction-materials firm Winsun New Materials says it has built 10 200-square-meter homes using a gigantic 3-D printer that it spent 20 million yuan ($3.2 million) and 12 years developing.

Such 3-D printers have been around for several years and are commonly used to make models, prototypes, plane parts and even such small items as jewelry. The printing involves an additive process, where successive layers of material are stacked on top of one another to create a finished product.

Winsun's 3-D printer is 6.6 meters (22 feet) tall, 10 meters wide and 150 meters long, the firm said, and the "ink" it uses is created from a combination of cement and glass fibers. In a nod to China's green agenda, Winsun said in the future it plans to use scrap material left over from construction and mining sites to make its 3-D buildings.

Its 3-D homes were printed in Suzhou and later assembled in Shanghai, and will be used by local authorities as offices, said Chen Jiajia, a Winsun engineer. Winsun says it estimates the cost of printing these homes is about half that of building them the traditional way. And although the technology seems efficient, it's unlikely to be widely used to build homes any time soon because of regulatory hurdles, Mr. Chen said.