Chinese construction company Broad Sustainable Building, which specializes in prefabricated buildings, managed to build a 57-storey skyscraper in just 19 days in the central city of Changsha, according to the official website.

The building, with 186,000 square meters, with capacity for 800 apartments and office space for 4,000 people, is the highest that has been achieved by now to build the company, which in previous years had already been known for its speed in building skyscrapers .

In 2010 the company built a 15-story hotel in 48 hours and the following year achieved what was so far its greatest achievement, another 30-story hotel that rose in 15 days.

According to one of the company's architects, Zhang Xianmin, modular construction is, in addition to fast, much more sustainable than conventional techniques, as it "reduces the use of cement in an amount equivalent to 15,000 trucks."

"This almost eliminates the emission of dust in the air, something very important in a China very affected by the pollution", emphasized the architect, who also underlined the energy efficiency of a building that saves the equivalent to 12,000 tons of carbon dioxide front To skyscrapers of the same size.

Broad Sustainable Building is the construction company that has proposed to build, also in the city of Changsha, which would be the highest skyscraper in the world (the so-called "Sky City", 220 floors).

A giant that the firm has promised to complete in 90 days, although the project is now paralyzed due to problems to get official approval and doubts about the economic viability or safety of the skyscraper