World's tallest skyscraper

Blazing fireworks and dazzling lights marked the inauguration of the world's tallest tower, Burj Dubai.

The needle-shaped concrete, steel and glass tower, described by its developer as a "vertical city" as it dwarfs existing skyscrapers, boasts new limits in design and construction.

Emaar Properties, the partly government-owned developer, has maintained the suspense over the final height of the skyscraper, saying only that it exceeds 800 metres (2,625 feet).

But it revealed on that the tower will have over 200 floors, only 160 of which will be inhabited, while the remaining floors will be for services.

Burj Dubai has a total built-up area of 5.67 million square feet, including 1.85 million square feet of residential space and over 300,000 square feet of prime office space, Emaar said. Related article: History of Dubai mega projects

This amounts to 1,044 apartments and 49 floors of office space, served by 57 lifts.

A hotel carrying the Georgio Armani logo will also occupy part of the tower.

Bill Baker, a structural and civil engineer and partner in Chicago-based Skidmore, Owings and Merrill (SOM), which designed the tower, said Burj Dubai has set a new benchmark.

"We thought that it would be slightly taller than the existing tallest tower of Taipei 101. (Emaar) kept on asking us to go higher but we didn't know how high we could go," he said.

"We were able to tune the building like we tune a music instrument. As we went higher and higher and higher, we discovered that by doing that process... we were able to reach heights much higher than we ever thought we could.

"We learned quite a bit from Burj Dubai. I would think we could easily do a one kilometre (tower). We are optimistic about the ability to go even higher."

A spiralling Y-shaped design by SOM architect Adrian Smith was used to support the structural core of the tower, which narrows as it ascends. Higher up it becomes a steel structure topped with a huge spire. Related article: The world's highest towers.

To reach the final stages, concrete was propelled to a height of 605 metres (1,996 feet) -- a world record.