There's something different about a group of small structures that just went up in western Shanghai. They were put together using a technique called additive manufacturing - better known as 3D printing technology.

From a distance, these ten gray buildings in suburban Qingpu District look just like the temporary housing you see on construction sites. But in fact, they were built without using a single brick or tile or piece of sheet metal.

If you look carefully, you see what's different about this structure. A 3D printer lays down successive 2-centimeter-thick layers of material. The ten structures cost 20,000-30,000 yuan ($3,180-4,770) each, and will be used as offices.

The ten houses were printed in just one day. Ma Yihe, CEO of Shanghai Yingchuang Design & Engineering Co., came up with the idea of using additive manufacturing 12 years ago. They bought parts for the printer overseas, and assembled it in a factory in Suzhou, east China's Jiangsu Province. Ma says the core of the technology actually lies in what you might call the "ink," which is a mixture of sand, concrete and glass fiber.

"The material has been transformed from industrial construction waste. It is lighter, but five times as hard as common construction material. All the layers are firmly connected with each other. They won,t separate or deform or collapse," Ma said.

Depending on the size of the building wanted, it can either be printed right on-site, or assembled from walls printed at the factory and then delivered. Then workers use cranes to stack them just like building blocks.

"The walls are hollow inside. The walls with beam columns are printed with steel bars inside. Workers can just pour the concrete directly into the walls. It's very simple to do. It's not against the current architectural principle, but can save up to 50 percent of the construction material," Ma said.

Since the material is produced in a fully-digital way through a central computer system, there are no ways to cut corners. Now he says he wants to open more recycling centers in China, and is applying for a patent.

However, a professor of architecture at Tongji University says the technology needs to be further tested for fire resistance, durability and internal structure before going into mass production. And glass fiber is still not widely accepted in China because it can harm people's respiratory systems.

So experts say that for now, the technology will be mainly used for temporary structures or for building affordable housing for the poor.

(CNTV.cn April 26, 2014)