The world’s cities are in the midst of a skyscraper boom, and not with just tall buildings, but with ones officially designated as “supertall.” Nearly 600 buildings of at least 200 meters—or about 60 stories high—are either under construction or in the planning stages. That would almost double the number that height within the next 10 years. Now only three skyscrapers are above 500 meters, or more than 1,600 feet. By 2020, there are expected to be 20 more.
Better and faster elevators make taller skyscrapers more practical
One of the key factors limiting how high buildings can go is the weight of steel elevator cables. If they stretch much beyond 1,600 feet, they’re at risk of snapping under their own weight. But a Finnish company has developed a cable it calls UltraRope, which is made of carbon fiber and weighs almost half as much. UltraRope, say engineers, will make a 300-story building possible.
More Mixed Use Skyscrapers
Growing upward is seen as a wiser, more sustainable option than sprawling outward. Since residential and retail spaces require narrower floor plates than offices, mixed-use buildings can go higher with the same amount of material. And skyscrapers with a lot of tenant options are a lot easier to fill. In 2000, only five of the 20 tallest buildings in the world were mixed-use; by 2020, only five won’t be.
Others are also going with modular and prefab construction
The Broad Group made a big splash in late 2011 when it erected a 30-story building in 15 days. That’s right, two weeks. It was able to do this only because each floor was pre-fabricated in a factory, then connected on-site. While it may be hard for most of us to imagine pre-fab skyscrapers, people in the high-rise business don’t think that’s far-fetched at all. Some even envision tall buildings of the future being built in a factory, then fitted together by an army of robots. Clearly, the modular approach is catching on. More than 60 percent of the $4.9 billion Atlantic Yard project in Brooklyn will be constructed off-site, including a 32-story building. And if Sky City does move forward, it would mean that the tallest building in the world would be modular. That’s how the company can plausibly talk about Sky City being finished by next spring. Speed is one big advantage. Cost is another. The Broad Group says Sky City should cost roughly $850 million to build. The Burj Khalifa in Dubai cost $1.5 billion.
Permits Still delaying the 838 meter Sky City
“So far, they’ve undergone the process to obtain 136 mu [22 acres] of land, but that’s it. They’re still in the very basic beginning stages. We’ve been giving a lot of attention to this case, and everything they’ve done has been according to law,” the rep added.
When questioned about resuming construction, Broad group said that the next start-date would be revealed in a press release. The press meet has not been scheduled yet.