Revealed: Plans to build the world's tallest building at 1km high

High times: An artist's impression of a new sky scraper in Dubai that, when built, could become the world's tallest building
Plans to construct what could become the world's tallest building, at more than 1km high, were unveiled today.

Dubai developer Nakheel - the company that created man-made islands in the shapes of a palm tree and the world - said the structure will be the centre-piece of an inner-city harbour set to become the emirate's new, unofficial capital.

It would not comment on exactly how high or how expensive the Islamic design-inspired Nakheel Tower will be. The building will have "more than 200 floors" and be part of "a multi-billion pound development", the company said.

But "tallest building" claims are notoriously difficult to make. Debates about what counts as a candidate include whether buildings under construction should be considered and whether roof-top antennas count.

What is certain is that the tower will climb above what is said to be current holder of the "world's tallest building" position - the emirate's own Burj Dubai.
Speaking at a press conference today, a cautious Nakheel chief executive officer, Christopher O'Donnell, said: "From our perspective, we are building a tower that's going to be over 1km in height. This is a complete iconic development. It may be the tallest. Someone may build something taller."
Hollywood power couple Catherine Zeta-Jones and Michael Douglas also attended the press conference.

The Nakheel Tower will have around 150 lifts and be built with some 500,000m3 of concrete. If the reinforcing bars planned were laid end to end, they would stretch from Dubai to New York.
The building will have enough cooling capacity to air-condition more than 14,000 modern homes.
It will be so tall that it experiences five different microclimatic conditions over its height. The temperature in the atmosphere at the top of the building could be as much as 10 degrees cooler than the bottom.
Planned high speed shuttle lifts will allow people to see the sunset twice - from the bottom and again from the top of the building.

The Burj Dubai was, until the new plans were announced, the world's tallest building. It will have ten years to enjoy the title before the Nakheel tower is completed