With a record-breaking speed, Chinese construction company 'Broad Sustainable Building Co' successfully built a 57-story skyscraper in just 19 working days in central China. “We are now the world's fastest builder,” the company claimed. The rectangular, glass-and-steel Mini Sky City has 800 apartments and office space for 4,000 people. The company plans to build a 220-floor skyscraper in 3 months.