You may not know that one of the main limiting factors in how tall skyscrapers can be is not wind sway, foundation depth or core strength - it's the weight of the elevator cable.
Steel cable like that currently used is so heavy at the 500-metre mark that the weight of it prevents hoisting systems from working.
A new type of cable could change all this.
Future towers could dwarf most of today's
UltraRope has a carbon fibre core surrounded by a special high-friction coating making it extremely light and very durable.
Five-hundred metres of UltraRope weighs 12,800kgs compared to 29,000kgs for the same length of steel cable.
It's makers, Kone, claim this will allow single elevators to reach heights up to 1,000, twice as high as the current limit.
Currently the only way for buildings to hope to reach this level is for people to switch lifts halfway up as happens in the 828-metre high Burj Khalifa in Dubai.
The technology could be used in China's bid to rob Dubai of the 'World's Tallest Building' crown when it erects the 838 metre high Sky City One - in just seven months.