The global skyline may be in for some radical changes as developers set their goals higher in a fresh race to the top.
The Saudi billionaire Prince Alwaleed bin Talal, who owns the Savoy hotel in London, reportedly plans to build a 1,600-metre skyscraper, and one of the cities he is looking at is Shanghai, together with London, Moscow and New York.
If built, the tower would be double the height of the world's current tallest building, the Burj Khalifa in Dubai, which is 828 metres high, and three times as tall as Hong Kong's tallest building, the International Commerce Centre in Kowloon, which is 484 metres tall.
The prince's dream project would also be taller than the 1,000-metre Kingdom Tower, itself almost twice as high as Hong Kong's Victoria Peak (552m), now being built by Kingdom Holding in the Saudi Arabian city of Jeddah, which will unseat the Burj Khalifa from its perch when completed.
Closer to home, the Hunan-based developer Broad Group, known for making giant air-conditioning systems, has drawn up plans to build a 838-metre building, Sky City, in Changsha, capital of Hunan province.
Though Sky City cannot hope to take the top slot in high-rise rankings, Broad Group is aiming for a different crown - speed. In November, the group announced that it would complete the 220-storey building in just 90 days.
Property experts, however, are not particularly impressed by this global high-rise competition.
Richard Kirke, managing director of Colliers International Hong Kong, said: "Extremely high office towers require so much additional structural reinforcements that over a certain height, the returns become uneconomic. The motivation is typically not economic.
"My belief is that this desire to build ever-higher buildings by a small number of global developers is a reflection of their wealth."
Building these needle towers is no small feat, as they involve serious technical and design challenges.
"It could be very dangerous in times of earthquakes or typhoons," said Bernard Lim Wan-fung, a professor at Chinese University's school of architecture.
"It's not practical. Would you want to move into one of those? I definitely won't."
In a report called Skyscraper Index , the investment bank Barclays Capital found an ominous link between the pursuit of the tallest and financial crises. It cited the examples of New York in 1930, Chicago in 1974, Kuala Lumpur in 1997 and Dubai in 2010, when competition to build the tallest tower coincided with economic meltdown.
Barclays said the completion of the current tallest, the Burj Khalifa, in 2010 coincided with the global financial crisis. It said that such building booms reflect widespread misallocation of capital and an impending economic correction.
However, Kirke said the latest construction boom was not a reflection of the current market conditions.
"The impact of a few exceptionally tall buildings to the office market will doubtlessly have a significant impact on local supply levels, but will not be significant in a macro level," he said.