DUBAI (AFP) - Sheikh Mohammad bin Rashed al-Maktoum, the ruler of Dubai, on Monday officially opened the worlds tallest building, which stands more than 800 metres high. Sheikh Mohammad unveiled a plaque and gave a brief speech during which he renamed the building the Burj Khalifa, after the United Arab Emirates president, Sheikh Khalifa bin Zayed al-Nahayan. 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 Monday that the tower 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. 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. Dubais ruler Sheikh Mohammed bin Rashed al-Maktoum will inaugurate the tower at 1600 GMT, in a ceremony that is set to feature dazzling laser lights and a fireworks show, in addition to choreographed water display by the Dubai Fountain that stretches 275 metres-long at the feet 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 didnt 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. (Photo by Daily Mail) 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. (Photo by Daily Mail) 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. To reach the final stages, concrete was propelled to a height of 605 metres (1,996 feet) a world record. The inauguration of the Burj Dubai comes, however, after the once-booming real estate sector of the emirate has crashed, halving the value of most Dubai properties in comparison with peak prices recorded in the summer of 2008. It also comes as Dubai battles a serious debt crisis, resulting from the heavy borrowing by some of its state corporates to finance grandiose real estate projects. The emirate had narrowly escaped a financial catastrophe last month as neighbouring deep-pocketed Abu Dbabi threw it a last-minute lifeline worth 10 billion dollars to pay imminent debt owed by its group Dubai World. The group began last month negotiations with its creditors with the hope of reaching an agreement over restructuring an accumulated debt of 22 billion dollars amassed by its troubled subsidiaries. Dubais total debt, mostly that of its state-owned companies, amounts to 100 billion dollars. Abu Dhabi, and the Abu Dhabi-based central bank of the United Arab Emirates, have already extended financial aid of 25 billion dollars to Dubai since it announced early in 2009 that it needed to sort the debt problem of its firms. Dubais economy was hard hit by the global financial crisis, which turned off the tap on vital foreign financing badly needed for its breakneck-speed growth.