Currently, the Burj Khalifa in Dubai is the World’s Tallest Building. Well, that record may soon change hands. Sky City, a 220-story tower may be taking its place. It will reportedly stand 2,749 feet tall. Scheduled to debut in China in 2014, it is a prefabricated structure, requiring 3 months of manufacturing time off site and an additional 7 months needed for assembly in Changsha.