Sky City ¨C an 838-meter tall super highrise is under planning in Changsha, the provincial capital of Hunan Province in China. Developed by Yuanda China Group, Sky City is probably the tallest building under planning in the world.
     The 220-storey mix-use building occupies a site area of approximately 17,000 square meters and will provide a total GFA of 1 million square meters. A total of 104 elevators will serve as vertical transport in the building. The project will accommodate commercial and office floors, hotel, residential units, schools, clinics and hospitals, etc.
     The super tall building will be constructed by prefabrication using sustainable building modules designed and fabricated by Yuanda's own factory. Approximately 93% of the building envelope and floor slab modules will be prefabricated and transported to the site for assembly. Construction waste generated by the project will be only 1% or less.
     Based on previous project experience in Hunan, Yuanda had completed the construction of a 30-storey hotel building in 15 days by using prefabrication method. It is expected that the 220-storey Sky City will take just 7 months to construct.
     Sky City is also a highly environmentally friendly building incorporating many green features such as: a specially designed 15-mm 4-layer ventilated external glass panel system for maximum thermal insulation, heat exchanger, LED lighting and advanced energy saving air-conditioning and lifts systems. The new building will be at least 5 times more efficient in energy saving than any traditional building of the same type.
     The planning of Sky City began in April 2012 and pending approval from the local government, construction is expected to commence in November this year. Upon completion in the first half of 2013, Sky City will be the tallest building in the world. Total investment of the project is estimated at no less than RMB4 billion (approximately US$667 million).