The Burj Dubai, set to open in January 2010, is regarded as currently being the world's tallest building, however a change in the 'tall buildings criteria' from the Council on Tall Buildings and Urban Habitat (CTBUH) could change that.
The CTBUH is an international body that decides on tall building height and determines the title of 'The World's Tallest Building', but yesterday the organisation announced a change to its height criteria.
Now, a building's height will be "measured from the level of the lowest, significant, open-air, pedestrian entrance" allowing, the body said in a statement, "for the recognition of the increasing numbers of multi-use tall buildings with often several different entrances at different levels, while also accommodating buildings constructed in non-traditional urban or suburban locations."
Before the change, the CTBUH measured the height of a building from the sidewalk outside the main entrance to the top, but they have now determined that this is no longer sufficient.
Overall, there are three revised height categories:
Height to architectural top
It is measured to the topmost architectural feature of the building including spires, but not including antennae, signage, flag poles or other technical equipment.
Height to highest occupied floor in a tower
It is measured to the level of the highest, consistently occupied floor in the building (thus not including service or mechanical areas which experience occasional maintenance access)
Height to tip
This is measured to the highest point of the building, irrespective of material or function of the highest element.
Burj Dubai affected?
So, could the Burj Dubai lose its title after just claiming it a few months ago? David Scott, ex-chairman at CTBUH and Principal at Arup doesn't think so.
"Throughout the process, we have been talking to them to define where the entrance is [the new criteria]. I do not think that it will have an impact on the current status of Burj Dubai."
"There is awareness within the Burj team of what we are talking about," he said.
"The developer Emaar is still confidential about the height of the building and we don't mind it being confidential. But if they open the Burj and don't release the height, then we will measure the height of the building. During construction it is fine, but after construction we want to know and our people want to know its final height.
"This new criteria is to solve instances where a tall building had no sidewalk and the connection to the building is through an open air shopping centre. We did not want to change the heights of all the buildings in the world, of course. But this decision has been taken to really clarify how to measure the heights for different buildings."
The Burj Dubai is said to be approximately 818m (2,684ft) tall making it the largest building in the world. However, other projects being constructed could be affected by the new rules.
The Trump International Hotel and Towers in Chicago will see 27 feet added to its height, as it will now be measured from its lower, publicly accessible Chicago Riverwalk. This means it will over take the Jin Mao Tower in Shanghai to become the world's sixth tallest building.
The Burj Dubai - still the tallest