From the pyramids of ancient Egypt to the medieval churches of Europe, mankind has long endeavored to construct buildings that reach the heavens. Thanks to advances in tall building design it's feasible to build skyscrapers that approach a kilometer in height and perhaps even a mile high will soon be possible too. Join us as we take a look at the cutting edge designs that make up the world's tallest skyscrapers.
Skyscraper construction has undergone a shift in the last couple of decades, with the baton for really tall buildings passed from west to east. More specifically, the oil-rich middle-eastern countries like the United Arab Emirates now lead the way in commissioning very tall buildings, followed closely by China, though the firms which design these buildings are usually western.
The rate of change is very impressive. The State of the Game back in 2015 is now totally transformed, and all but one of the buildings we featured then has dropped a position (or several) in the world's tallest rankings. Rankings are decided by the Council on Tall Buildings and Urban Habitat (CTBUH), the leading authority on tall building construction.
Read on for the 10 tallest buildings today, and be sure to head to the gallery for more photos of each of the buildings listed.
10th: International Commerce Centre
Kohn Pedersen Fox (KPF) designed the International Commerce Centre, the 10th tallest skyscraper in the world. Make a note of that name by the way, as the influential American firm dominates this list, and is responsible for half of the world's top 10 tallest skyscrapers.
Construction began on the project in 2002 and was finished in 2010. On completion, it was officially ranked the 4th tallest building in the world, but has slipped position in the meantime. The skyscraper rises almost half a kilometer over Hong Kong, measuring an official height of 484 m (1,588 ft). Used primarily for office space, but with hotel space too, notable features in this building include its double-decker elevators.
Also, Wikipedia notes that all floor numbers containing four (4, 14, 24, etc) were omitted due to the word sounding very similar to death in Chinese. This isn't as unusual as it sounds, and several other buildings in that part of the world also have floors named in that way.
9th: Shanghai World Financial Center
The Shanghai World Financial Center, again by KPF, is a really unusual-looking skyscraper that rises to a total height of 492 m (1,614 ft), and includes offices, hotels, and retail space.
Completed in 2008, its overall shape reflects the ancient Chinese symbols of heaven and earth. In addition to making it look so unique, the trapezoid void towards the top of the skyscraper also serves the practical purpose of reducing wind loads.
The skyscraper includes an impressive observation area which allows visitors to walk and take in the view of Shanghai from almost half a kilometer up. In a novel little touch, its gift shop sells miniature Shanghai World Financial Center model skyscrapers that serve as bottle openers.
8th: Taipei 101
From its completion in 2004 until the Burj Khalifa surpassed it in 2009, the Taipei 101 (aka Taipei World Financial Center) in Taiwan was rated the world's tallest skyscraper.
Designed by C.Y. Lee & Partners Architects, it rises to a total height of 508 m (1,667 ft), and is designed to take the severe winds and earthquakes that can occur in the region in its stride. Indeed, it has a very solid-looking design consisting of multiple volumes that flare outward, bringing to mind the traditional Chinese pagoda.
Though it has lost "world's tallest" bragging rights, in recent years Taipei 101 has become a leader in tall building sustainability. The skyscraper received a Platinum award from LEED (a top green building standard), and now includes an energy-efficient double-paned glass curtain wall, low-flow water fixtures and an advanced energy management systems.
To be clear, you can't really call a building like this "environmentally friendly" in any meaningful sense, but the strive towards energy-efficiency is laudable.
7th: Guangzhou CTF Finance Centre
Another skyscraper by KPF, the Guangzhou CTF Finance Centre stands out from the crowd with its distinctive terracotta cladding. Measuring 530 m (1,739 ft)-tall on a site overlooking the Pearl River, it includes office space, residential space, and a hotel.
The decision to use terracotta came about both for historical reasons (it's a nice nod to China's famous Terracotta Army), and because it can be produced locally in a more environmentally-friendly manner than aluminum, glass, or steel. Terracotta is also more resistant to corrosion than usual skyscraper building materials and provides a better thermal performance than an all-glass curtain wall would.
Opening in October, 2016, the Guangzhou CTF Finance Centre is used by over 30,000 people each day. They get around using 95 Hitachi-designed elevators, which are among the world's fastest and travel at speeds of 72 km/h (44.7 mph).
6th: One World Trade Center
The One World Trade Center by Skidmore, Owings & Merrill (SOM), is the only western skyscraper in the Top 10 tallest rankings. Still, what the United States lacks in quantity, it more than makes up for in quality.
Taking its name from the North Tower that was destroyed on September 11, 2001, the One World Trade Center rises to 1,776 ft (541 m), reflecting the year that the United States made its historic Declaration of Independence from Great Britain.
Its overall form is inspired by the tapering style of classic New York City skyscrapers and is anchored by a cubic base with roughly the same footprint as the original North Tower. Over 40 percent of the materials used in construction were recycled and more than 87 percent of construction waste was diverted from landfill.
The building officially opened back in 2014 and is over-engineered to far exceed NYC Building Code requirements. Life-safety systems, including exit stairs, communication antennae, exhaust and ventilation shafts, and elevators, are encased in a concrete core that's a minimum of 2 ft (0.6 m) thick. Despite its considerable heft, it's still a beautiful building.
5th: Lotte World Tower
KPF's Lotte World Tower reaches a height of 555 m (1,820 ft) in Seoul, South Korea and is defined by an unusual silvery design inspired by traditional Korean ceramics, porcelain and calligraphy. Inside its 123 floors, the building includes office space, hotel space, retail space and officetels (studio apartment accommodation for workers).
The skyscraper's glass-bottomed observation deck is located near the top of the building, at a height of 497.6 m (1,633 ft), and offers fantastic views. To get up there, visitors travel in the world's fastest elevator, which can zoom from bottom to top of the tower within a minute – this must be pushing the envelope of how fast an elevator can travel without passengers losing their lunch.
The skyscraper includes some sustainable technology, including solar panels, wind turbines, and water-harvesting systems. It officially opened in April 2017.
4th: Ping An Finance Center
Completed in 2016, the Ping An Finance Centre, by KPF, is located in Shenzhen's central business district and comprises 462,000 sq m (4,973,000 sq ft) of floorspace, spread over 100 floors, and is mostly taken up by office space. It rises to 599 m (1,965 ft) in height.
Each day, the building accommodates up to 9,000 visitors to its impressive observation deck, which is located at a height of 550 m (1,804 ft), making it just a few meters short of the world's tallest observation deck, installed in the Burj Khalifa.
The Ping An Finance Centre's tapering form consists of a sculpted facade shaped to mitigate the effects of wind. Stone chevron-shaped columns converge at the tower's top and stainless steel protrusions protect the building against lightning strikes.
3rd: Makkah Royal Clock Tower
Located in the heart of Mecca, Saudi Arabia, the Makkah Royal Clock Tower rises to 601 m (1,972 ft) and is surrounded by six smaller buildings rising to various heights. It includes a hotel, observation decks, exhibitions and more, but is dominated by four huge clock faces, which are the largest and highest in the world.
At night, the clocks are illuminated by 1 million LEDs, with the writing God is the Greatest on the north and south sides. Verses from the Koran adorn the east and west-facing sides.
The spire of the tower features a spherical observation center at its base and is topped by a shining gold crescent.
2nd: Shanghai Tower
Gensler's Shanghai Tower does the twist with an eye-catching design that rotates a total of 120 degrees from ground to tip. This reduces the crushing wind loads that batter the skyscraper at its maximum height of 632 m (2,073 ft) by an impressive 24 percent.
The project took six years of work, finally completing in 2016. Its foundations required a fleet of trucks to pour concrete non-stop for 63 hours. 106 Mitsubishi-designed elevators travel at speeds of up to 20 m (65 ft) per second to allow visitors to navigate the 128 floors, and it includes a total of 420,000 sq m (4,520,842 sq ft) of floorspace.
The building is clad with a double-layered glass skin and sports a total of 270 wind turbines, which provide all power required for external lighting. Its funnel-shaped parapet channels rainwater into large tanks, which is used for air-conditioning and heating systems. These measures, as well as others, ensured the building was awarded a LEED Gold rating.
1st: Burj Khalifa
This is the big one. Though it officially opened back in 2010, the Burj Khalifa, by SOM, still remains the world's tallest skyscraper by a long way. Also the tallest free-standing structure in the world, the skyscraper rises to an incredible 829.8 m (2,723 ft) over Dubai and comprises 160 stories.
At this point all these numbers might have become a little meaningless and jumbled, so to put it into perspective, you'd need to stack around 11 Boeing 747-8 airplanes, tail to tip, to match the height of the Burj Khalifa. Or roughly 2.5 Eiffel Towers.
Inside, its total floorspace is 334,000 sq m (3,595,146 sq ft), which is over twice the floorspace of China's Forbidden City, or four times that of London's Buckingham Palace. You could theoretically fit Paris' Louvre Palace and still have space to accommodate Russia's Winter Palace and England's Windsor Castle for good measure.
Delve a little deeper into the practicalities of building something like this for a minute and you get a better sense of the engineering achievement it represents. Take something as mundane as the concrete, for example: Dubai gets extremely hot in summer, so to prevent it from spoiling, workers had to mix in ice rather than water.
Then there was the issue of pumping the concrete up to a height of 600 m (1,968 ft). Special mixes had to be used, along with some of the world's largest pumps, sending the concrete up at amazing pressures.
There's also the wind, which would crush a lesser-designed tower. The Burj Khalifa features a novel design involving changes at each setback, which according to SOM, "confuses" the wind and prevents wind vortexes from building up and becoming dangerously powerful.
Drawing inspiration from a desert flower and classic Islamic architecture, the design is nonetheless very practical and efficient. Built from reinforced concrete and clad in glass, the skyscraper actually uses less steel than NYC's Empire State Building, despite being almost twice its height. It's arranged in a Y-shaped footprint and rises from a flat base in a spiraling pattern, steadily reducing mass as it reaches upwards. At its pinnacle, the central core emerges and is sculpted into a spire.
The Burj Khalifa has stood as the tallest building in the world for an impressive period, but it will likely be surpassed eventually. Indeed, the Jeddah Tower promises to do so in the coming years. However, it will remain a major milestone in mankind's continuing quest to build ever-higher.