If the speed of China's rise has been astonishing, it's about to get even faster. A Chinese construction firm has pioneered a modular construction technique that allows it to build energy-efficient skyscrapers in a matter of weeks, dramatically reducing construction costs and waste. This year, Broad Group will put that approach to the ultimate test when it builds a 220-story skyscraper -- to be the world's tallest -- in a mere 90 days in Changsha, in southeast China. (The world's current tallest building, the more than 160-story Burj Khalifa in Dubai, took six years to complete.)
Although the feat might sound far-fetched, Broad has proved itself capable in a series of trial runs. This past December, it completed a 30-story hotel near its headquarters in Changsha in just 15 days. The approach utilizes prefabrication -- 93 percent of the work on the hotel took place in a factory -- resulting in 1 percent of the waste of a normal building project. Also, by assembling large portions of the building beforehand, engineers can seamlessly integrate green features into the structure, such as thermal insulation and electricity-generating elevators. Already, Broad says it has franchised its methods to six Chinese companies and is in talks with two companies abroad.