Last June, Broad Sustainable Building announced that it would need only 90 days to complete the Sky City Tower in the middle of a field in China's Hunan Province. At 2,749-feet high, the building would be the tallest on Earth. Now, they're saying it will take closer to six months, which is still remarkable considering its size. According to BSB founder, "Traditional construction is chaotic...We took construction and moved it into the factory...It's not a construction company. It's a structural revolution."