AboutTime Issue 30 | Page 10

GLOBAL SPOTLIGHT Flat pack 57-storey skyscraper built in 19 days Chinese entrepreneur Zhang Yue took less than three weeks to build world’s tallest prefab tower The Mini Sky City tower in the city of Changsha, China. SOURCES www.archdaily.com, www.cnn.com, www.bbc.com, www.bdcnetwork.com,www.ft.com and www.inhabitat.com On the outskirts of Changsha, the capital of Hunan province in southern China, stands a 57-storey tower. It is not known for its architectural design or height, but rather for the speed at which it was built in 2015 by Broad Sustainable Building (BSB), a Chinese firm that specialises in prefabricated construction. “Three floors in a day is China’s new normal,” says a representative for the Mini Sky City tower skyscraper that was built in just 19 days. The tower was built in two bursts: the first 20 storeys went up in a week in 2014, but red tape held up construction for a year, with the final 37 storeys completed in 12 working days in February 2015. Inhabitat.com names it the world’s tallest prefab tower. The 180 000 sqm mixed-use building was assembled from thousands of factory-made steel modules, slotted together like Meccano. The process also claimed to have required less materials and significantly reduced the amount of air pollution.  The tower is comprised of 19 ten-metre-high atriums, 800 apartments and office space for 4 000 people. According to CNN, by preparing more than 2 700 modules in a factory for four months before site work began, BSB says it was able to assemble the structure at the rate of three stories per day - like a giant vertical jigsaw. To put the pace of BSB’s construction into context, it took 16 months to build the Barclays Head Office in Gaborone which is effectively 8 floors tall. BSB Chairman Zhang Yue says his method is not only fast, but also safe and cheap. Now he wants to use the same technique to build the world’s tallest skyscraper, Sky City. BBC reports that while the current 10 record holder, the 828m-high Burj Khalifa in Dubai, took five years to “top out”, Yue says his proposed 220-storey tower that will reach nearly 840-metres will take only seven months - four for the foundations, and three for the tower itself. And it will be 10m taller. Safety concerns There have been questions regarding the labour and safety practices employed during its construction given the sheer speed of assembly. CNN reports that a detailed company slideshow from BSB’s Sky City project, however, states that the company’s buildings are all constructed by skilled “professional workers” and not “day labourers.” According to the Financial Times, Sky City has been put on hold because of concerns about the safety of BSB chairman Zhang Yue’s proprietary technology. Shipping flat packs across the globe BSB is aiming to sell buildings worldwide, making them in China and shipping them across the globe. Austin Williams, associate professor in architecture at Xi’an Jiaotong-Liverpool University in the city of Suzhou told CNN that fast-build projects like Mini Sky City could be extremely useful for housing needs in other parts of the world. Urbanisation is already happening at a rapid rate across many parts of Asia and Africa. More than 2.5 billion people will be added to the world’s urban population by 2050, according to the U.N. 2014 World Urbanisation Prospects report. And nearly 90% of this growth is expected to be concentrated in Asian and African cities. ISSUE 30 - JUNE 2017