The world's tallest building - Burj Dubai - reaches 2,257ft...and it's still growing

This is Burj Dubai and, once again, the editors of the Guinness Book Of Records have got to rewrite the chapter on buildings.

This is not simply the tallest structure in the world; it smashed the tallest-building record a year ago and, this April, it overtook the world's tallest antenna.

Tall mystery: Final height is a secret

World's tallest: Burj Dubai

Now it has gone one further. As of this week, Burj Dubai - meaning 'Dubai Tower' -  has officially become the tallest man-made thing ever.

From its 2,257ft (688m) peak, you do not merely view the entire Gulf state of Dubai. On a good day, you can see 100 miles away into sunny Iran. And the Burj Dubai has not stopped growing.

It already boasts 160 floors and the developer, Emaar, is adding new ones at the rate of around one per week. Its eventual height remains a secret in order to confuse any rival constructors.

'Only a handful of senior designers know the final idea,' says project director Greg Sang, adding that Dubai's ruler, Sheikh Mohammed al-Maktoum, is also in on the plot.

'But I can say that we will be going above 700m.'

When it is finished some time next year, Burj Dubai will accommodate up to 35,000 people in a mixture of hotels, offices and apartments and, doubtless, it will clock up a few more records en route.

For example, the swimming pool on the 76th floor will almost certainly be the highest of its kind in the world.

Visiting the site recently, my initial problem was absorbing the size of the thing without damaging my neck.

The answer was to lie down on the road and look up. There is no scaffolding and all the building work goes upwards from the inside.

Every tool is attached to its user by a lanyard and safety codes are rigidly enforced among all 5,000 construction workers. Thus far, the project has claimed two lives.

New Zealand-born Greg, 42, has built several skyscrapers, including an 88-storey tower in Hong Kong.

The key to this one, he says, is to use tried-and-tested techniques: 'There is no magic, no special invention. With a project like this, it's no time to start experimenting.'

I am afraid I cannot look at this without a bubble appearing over my head containing the words 'Twin Towers'.

But the developers point out that this building is made from heavy-duty concrete, whereas the World Trade Centre, which collapsed after the 9/11 attacks of 2001, was a steel frame.

Extreme: Once completed the tower will surpass 700m

Safety features include reinforced 'refuge rooms' on every 25 floors, complete with independent air supplies, plus extra staircases and luminous paint on all escape routes.

The supporting pillars have been designed with a 'long-wave' effect to absorb any earthquake activity along the Iran/Iraq faultline.

The foundations drop 150ft (46m) below ground and the three-pronged 'footprint' of the building replicates the design of a desert flower.

The first eight floors will consist of a hotel, restaurants, gyms and a nightclub.

Floors nine to 37 will be 'Armani residences' -  luxury flats designed by the Italian fashion house.

There are a few more floors of hotel around the 40-storey mark and then floors 42 to 108 will be more apartments.

From 112 to the top will be offices, and Emaar is still open to offers for the top floor (whatever number it may be).

Other features include an observation platform on the 124th floor, while the tallest restaurant in the world will be on the 122nd floor.

And linking the whole lot will be double-decker, 42-man elevators travelling at up to 40mph.

For all the superlatives, Greg acknowledges that, one day, his creation will be overtaken. But when?

Until April, the world's tallest structure was a 2,063ft (629m) television mast in North Dakota, U.S.

How the Burj Dubai compares to the tallest towers in the world

But the all-time tallest was an old communist radio mast in Poland which reached 2,121ft (647m) in 1974, and then fell down in 1991.

Now, Burj Dubai has officially - and comfortably - beaten that record, too.

Childish arguments about the world's tallest buildings - as opposed to masts - have been going on for years, as rival skyscrapers have claimed the record.

But Burj Dubai is now unassailable. The old squabble between Toronto's CN Tower, Chicago's Sears Tower and Taipei's '101' building is redundant.

Compared to Burj Dubai, they are midgets.

For the first time in centuries, the Middle East can again lay claim to the world's tallest building.

For thousands of years, the title belonged to the Great Pyramid of Giza (481ft or 147m); from 2570BC right up until 1311AD, when it was overtaken by Lincoln Cathedral.

Various European churches then claimed the record until the Eiffel Tower popped up in 1889, followed by a 20thcentury outburst of U.S. skyscrapers.

As I lie in the road, gawping at Greg's handiwork, another thought occurs: how will they clean the windows?

'Oh, we'll have gondolas which flip out on cantilevered arms,' he says nonchalantly. 'The guys can clean it in the usual way with a hose and a squeegee.'

If that sounds like the worst job in Dubai, then think again. There will be an aviation warning-light in a mast up on the roof. And, every now and then, one poor soul will have to get up there to change the bulb.