How high is too high? Understanding supertall and megatall buildings

When the Empire State Building was completed in 1931, it stood as the world’s tallest building for almost 40 years at a height of 443.2 metres (spire included). In the 1930s, it may have seemed impossible that we’d ever build something taller than the distinctive Art Deco icon – even more improbable that we’d do so in a matter of decades.

But surpass it we did. In the 1970s, the World Trade Center towers topped out at 417 metres. Just 40 years – and many record-breaking buildings later – the Burj Khalifa in Dubai hit a mind-boggling 828 metres, close to a kilometre off the ground.

With architects not wanting to be outdone, we’re going to see a series of even taller buildings in the next few years. These are buildings so tall they need entirely new classifications.

The baseline: Tall buildings

Before delving into the realm of super- and mega-tall buildings, let’s first explore tall buildings. The Council on Tall Buildings and Urban Habitat (CTBUH) notes that there’s no real hard line for what constitutes a ‘tall’ building, agreeing that anything over 14 storeys or 50 meters constitutes ‘tall’.

As an aside, the organisation explains that a 14-storey building in Chicago or Hong Kong may not be considered a tall building, but in a smaller town it almost certainly will be.

The two groups below, supertall and megatall, are subgroups, with the latter being the newest. As of September 2017, there are only three completed megatall skyscrapers.

Supertall

Moving up from tall buildings, you arrive at the supertall classification. This is anything over 300 metres and up to around 600 metres, with a good example being the 432 Park Avenue tower in New York City at 426 metres. If you’ve ever seen it, you’ll no doubt agree with the classification.

Other supertall buildings include:

One World Trade Center in New York City, USA (546 metres) KK100 in Shenzen, China (442 metres) Ocean Heights in Dubai, United Arab Emirates (310 metres)

Megatall

The current limit to our classification system, megatall buildings cover those structures 600 metres and higher. There aren’t many right now, but the next decade will certainly be the age of the megatall skyscraper.

Current examples include:

Burj Khalifa in Dubai, United Arab Emirates (828 metres) Abraj Al-Bait Clock Tower in Mecca, Saudi Arabia (632 metres) Shanghai Tower in Shanghai, China (601 metres)

And future (under construction) examples include:

Jeddah Tower in Jeddah, Saudi Arabia (1,000+ metres) Wuhan Greenland Center in Wuhan, China (636 metres) KL118 in Kuala Lumpur, Malaysia (630 metres)

Towers of Babel

So, why do we need skyscrapers of such colossal heights? While companies, governments and architects may point to the benefits of cramming more into less, the simple answer is because it’s possible. It’s essentially a contest of who can make the biggest thing.

Take a look at many of the megatall structures and you’ll find an interesting correlation – they’ve all got dozens of empty floors. Just take a look at this image from Gawker. While advances in construction and materials mean we can make buildings taller and taller, much of the height is actually unusable or simply used for radio transmission. It’s ‘vanity height’. If you were to take off the non-occupiable part of the Burj Khalifa, the tower would lose 213 metres!

That’s not to say, however, that the towers we’ll see in the next few decades will follow this trend. There’s a good chance that as we get better at creating tall buildings, we’ll be able to build them with more usable space.

Just what we’ll do with all that space is another question entirely.

The hypothetical megastructures of the future

Are ultratall buildings on the horizon? Not quite, or at least not yet. While the Burj Khalifa is the tallest building in the world at present, architects and designers have proposed a number of structures that would make it look tiny in comparison.

Take the X-Seed 4000. Buckle in, this mammoth structure is as Blade Runner-esque as the implies.

Designed by the Taisei Corporation in 1995 for Tokyo, this structure would have risen 4,000 metres above sea level, with a base spanning six kilometres. The idea was to create a futuristic, basically self-contained living environment with room for 500,000 to 1,000,000 million people.

A few interesting notes:

The building would be 224 metres taller than Mount Fuji The cost to construct, adjusted for inflation, is estimated at up to $1.9 trillion USD

Unfortunately, Taisei Corporation never intended to go ahead with this project – if it would even be possible. The idea was to bring some attention to the firm, which certainly worked!

What next?

For supertall (or megatall) skyscraper enthusiasts, the next 10 years are set to be exciting. CTBUH believes that the number of megatall structures will rise from 3 to 7 in the next 5 years alone.

"With supertall skyscrapers more common than ever, many look to the megatall distinction as the new frontier for the world's tallest buildings," CTBUH explained.

"That includes Jeddah Tower, which will become the world's tallest building and the first kilometre-high building upon completion."

"There are currently only three completed megatall buildings in the world, but that number is set to more than double in the coming years as four more – including Jeddah Tower – come online," the organisation said.

The race to the top doesn’t seem to be slowing. In fact, it might not be long before we have to consider an entirely new form of classification.

Story by: Trends