The tallest building in the world and still growing

It is the tallest man-made structure in the world – and it is still growing.

When complete next year the Burj Dubai will stretch half a mile into the sky over the United Arab Emirates, taller than three Canary Wharf towers balanced on top of each other.

Already 2,200ft tall, and the result of 22million man hours of labour, the Burj is the pinnacle of skyscraper engineering. This £2 billion marvel, designed by American architect Adrian Smith, is packed with technological innovations, including double-decker lifts that can carry 42 people at a record-breaking 40mph to the observation platforms, robotic window-cleaning platforms and a system of pipes to collect condensation from the windows.

It will provide about 15million gallons of water per year – equivalent to nearly 20 Olympic-sized swimming pools. The water will be pumped into the site's irrigation system for use on the landscaped areas. Because of its size – more than 6,000 miles of girders, enough to stretch a quarter of the way round the world, have gone into making its 160 floors – evacuation in a fire could be too slow.

Therefore pressurised air-conditioned refuges to allow heat or fumes to escape are situated on every 25th floor, the stairwells are fireproofed and there is a special lift for firefighting equipment. The Burj will be the height of luxury. Some of the space will be used for offices but the lower 37 floors will house the world's first Armani Hotel.

There are also 700 private apartments, and residents will be able to swim in an outdoor pool on the side roof of the 78th floor. The Y-shape plan of the tower, copied from Islamic designs on mosque roofs, maximises views of the Persian Gulf.