The world has seen an explosion of new skyscrapers over the past decade, as rapidly developing Asian and Middle Eastern countries fall over each other to build the world's tallest, or the world's most eye-catching, new high-rise.
And as the buildings grow taller and more extravagant, costs rise with them, says construction data firm Emporis.
The company has put together a list of the world's most expensive skyscrapers; most of them were built in the past decade and not one of the buildings comes in under $1 billion U.S.
The most expensive, and by far, is One World Trade Center in New York, the building completed last month on the site of the towers destroyed in the 9/11 attacks. The cost? $3.9 billion.
There are many reasons for that huge sum, not least of which are the various security measures taken to prevent another 9/11. For many other buildings, costs associated with green technologies are driving up construction prices.
Here are the world's 10 most expensive skyscrapers, according to Emporis. (All figures in U.S. dollars.)
The Chifley Tower has an enormous hydraulic pendulum inside that ensures the building doesn't sway too much in high winds. It's one of Australia's most prestigious office and retail addresses. Completed in 1992.
John W. Cahill via Emporis
This "eco-friendly" skyscraper features many green innovations, such as waterless urinals and a 960-foot spire that acts as a windmill, generating power for the building. Completed in 2009.
This concert hall in Hamburg is a case of runaway cost overruns. It was originally estimated to cost about $550 million and was sheduled to open in 2010. The cost has now exceeded $1 billion and opening is scheduled for 2016.
Mith252 via Emporis
This bank building in Singapore will have greenery on its facade when finished, and will have a "sky forest" on the roof.
Scheduled for completion in 2014.
MAD Architects, XiaZhi via Emporis
Yes, this is a Sheraton hotel, and it's located at a hot springs resort near Shanghai. The building's shape made it costly to build, but the upshot of the design is that it enables all the rooms in the hotel to have a view and daylight from all directions, Emporis says. Completed in 2013.
This building holds the crown for world's tallest, but it's only fifth when it comes to world's most expensive. The building's 163 storeys require double-decker elevators that move at up to 600 metres per minute. The building is so huge the condensation from its AC system could fill 20 swimming pools every year, and is used to water the building's grounds. Completed in 2010.
This building was briefly the world's tallest, and its unqiue design is based on the number eight, a lucky number in Chinese culture. It was built according to the principles of Feng Shui, and, like the Burj Khalifa that replaced it as the world's tallest building, it features double-decker elevators. Completed in 2004.
Eric Smerling via Emporis
London's latest recognizable landmark has a hotel, offices and the city's highest residential apartments, which occupy the top floors. Plenty of eco-innovations in this building, including energy-saving amterials that cut power consumption by 30 per cent. This was Europe's first building to exceed 1,000 feet in height.
Completed in 2013.
It's hard to believe that Las Vegas, where any hotel can expect to be torn down within a generation or two, would build one of the world's most expensive buildings, but here's the proof -- a luxurious, 53-storey hotel that is now the tallest building in Vegas.
Completed in 2007.
This is the building that replaced the twin towers destroyed on 9/11, so it's understandable that New Yorkers would want it to be something special. And special it is, to the tune of $3.9 billion, more than twice as expensive as the second-most expensive building on this list.
The building features numerous safety measures, including refuge areas on each floor, enhanced fire-proofing and a separate staircase for firefighters. The elevators are located within a central "core" building inside the building, that also contains the building's life-safety systems, such as sprinklers and communications. Better safe than sorry.
Completed November, 2014.
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