Burj Dubai (برج دبي "Dubai Tower") is a skyscraper under construction in the Business Bay district of Dubai, United Arab Emirates, and is the tallest man-made structure ever built, despite being incomplete. Construction began on September 21, 2004 and is expected to be completed and ready for occupation in September 2009.
The building is part of the development called "Downtown Dubai", at the "First Interchange" (aka "Defence Roundabout") along Sheikh Zayed Road at Doha Street. The tower's architect is Adrian Smith who worked with Skidmore, Owings and Merrill (SOM) until 2006. The architecture and engineering firm SOM is in charge of the project. The primary builders are Samsung Engineering & Construction and Besix along with Arabtec. Turner Construction Company was chosen as the construction manager.
The total budget for the Burj Dubai project is about US$4.1 billion and for the entire new 'Downtown Dubai', US$20 billion. Mohamed Ali Alabbar, the CEO of Emaar Properties, speaking at the Council on Tall Buildings and Urban Habitat 8th World Congress, said that the price of office space at Burj Dubai had reached $4,000 per sq ft (over $43,000 per sq m) and that the Armani Residences, also in Burj Dubai, were selling for $3,500 per sq ft (over $37,500 per sq m).
Note: Additional records for tallest skyscraper are considered unofficial. On July 20, 2007, the head of the Council on Tall Buildings and Urban Habitat (CTBUH), Antony Wood, said "We will not classify it as a building until it is complete, clad and at least partially open for business to avoid things like the Ryungyong project. Taipei 101 is thus officially the world's tallest until that happens."
The projected final height of Burj Dubai is officially being kept a secret due to competition from other buildings under construction or proposed; however, figures released by a contractor on the project have suggested a height of around . Based on this height, the total number of habitable floors is expected to be around 162. However, Burj Dubai's construction manager, Greg Sang, has said only that the final height would be greater than , and that it would be the world's tallest free-standing structure when completed.
Though unconfirmed, Burj Dubai has been rumoured to have undergone several planned height increases since its inception. Originally proposed as a virtual clone of the Grollo Tower proposal for Melbourne, Australia's Docklands waterfront development, the tower was redesigned with an original design by Skidmore Owings and Merrill seen above and discussed below. Contradictory information abounds regarding the official height of the building, which is to be expected, considering the building seeks to acquire the designation as the world's tallest structure upon completion in 2009.
The design architect, Adrian Smith, felt that the upper-most section of the building did not culminate elegantly with the rest of the structure, so he sought and received approval to increase it to the currently planned height. It has been explicitly stated that this change did not include any added floors, which is fitting with Smith's attempts to make the crown more slender. However, the top of the tower has a steel frame structure, unlike the lower portion's reinforced concrete. The developer, Emaar, has stated this steel section may be extended to beat any other tower to the title of tallest; however, once the tower is complete, height increases will not be recognised.
The design of Burj Dubai is derived from patterning systems embodied in Islamic architecture, with the triple-lobed footprint of the building based on an abstracted version of the flower hymenocallis. The tower is composed of three elements arranged around a central core. As the tower rises from the flat desert base, setbacks occur at each element in an upward spiralling pattern, decreasing the cross section of the tower as it reaches toward the sky. At the top, the central core emerges and is sculpted to form a finishing spire. A Y-shaped floor plan maximizes views of the Persian Gulf. Viewed from above or from the base, the form also evokes the onion domes of Islamic architecture. During the design process, engineers rotated the building 120 degrees from its original layout to reduce stress from prevailing winds. The tower, at its tallest point, sways a total of .
The exterior cladding of Burj Dubai will consist of of reflective glazing, and aluminium and textured stainless steel spandrel panels with vertical tubular fins. The cladding system is designed to withstand Dubai's extreme summer temperatures.
The interior will be decorated by Giorgio Armani. An Armani Hotel, the first of four by Armani, will occupy the lower 37 floors. Floors 45 through 108 will have 700 private apartments on 64 floors (which, according to the developer, sold out within eight hours of going on sale). An outdoor zero-entry swimming pool will be located on the 78th floor of the tower. Corporate offices and suites will fill most of the remaining floors, except for a 123rd floor lobby and 124th floor (about ) indoor/outdoor observation deck. The spire—itself over tall—will hold communications equipment.
It will also feature the world's fastest elevator, rising and descending at . The world's current fastest elevator (in the Taipei 101) travels at . Engineers had considered installing the world's first triple-decker elevators, but the final design calls for double-deck elevators. A total of 56 elevators will be installed that can each carry 42 people at a time.
Outside, and at a cost of Dh 800 million (US $ 217 m), a record setting fountain system is to be designed by WET Design, the California-based company responsible for the fountains at the Bellagio Hotel Lake in Las Vegas. Illuminated by 6,600 lights and 50 colored projectors, it will be long and will shoot water into the air, accompanied by a range of classical to contemporary Arabic and world music.
The tower is being constructed by a South Korean company, Samsung Engineering & Construction which also built the Petronas Twin Towers and the Taipei 101. Samsung Engineering & Construction is building the tower in a joint venture with Besix from Belgium and Arabtec from UAE. Turner is the Project Manager on the main construction contract.
The primary structural system of Burj Dubai is reinforced concrete. Over of concrete, weighing more than were used to construct the concrete and steel foundation, which features 192 piles buried more than deep. When completed, Burj Dubai's construction will have used of concrete and of steel rebar (enough to extend over a quarter of the way around the world if laid end-to-end); and construction will have taken 22 million man hours.
As construction of the tower progresses, it becomes increasingly difficult to vertically pump the thousands of cubic metres of concrete that are required. The previous record for pumping concrete on any project was set during the extension of the Riva del Garda Hydroelectric Power Plant in Italy in 1994, when concrete was pumped to a height of . Burj Dubai now holds this record as of August 19, 2007, as it has a height of , to hold the record for concrete pumping on any project; and as of November 8, 2007 concrete was pumped to a delivery height of .
Special mixes of concrete are made to withstand the extreme pressures of the massive weight of the tower; as typical with reinforced concrete construction, each batch of concrete is tested and checked to see whether it can withstand certain pressures. The head of Concrete Quality Checking on the Burj Dubai project is Alam Feroze, who is in charge of concrete on the whole project. The concrete pumps, pipelines and booms are provided by Putzmeister, of Aichtal, Germany.
The consistency of the concrete on the project is essential. It was difficult to create a concrete that could withstand the thousands of tonnes bearing down on it and also withstand Gulf temperatures that can reach . To combat this problem, the concrete is not poured during the day. Instead, ice is added to the mixture and it is poured at night when it is cooler and the humidity is higher. A cooler concrete mixture cures evenly throughout and therefore is less likely to set too quickly and crack. Any significant cracks could put the whole project in jeopardy.
The unique design and engineering challenges of building Burj Dubai have been featured in a number of TV documentaries, including the Big, Bigger, Biggest series on the National Geographic Channel in the USA, and Five in the United Kingdom, and the Mega Builders series on the Discovery Channel.
The United Arab Emirates dirham's being pegged with the low US Dollar, and the increased cost-of-living in the region, has made it increasingly difficult for immigrant construction workers to survive on their wages. An offer by the UAE government in June 2007 to fly home illegal immigrant workers free-of-charge, with no questions asked, was met with overwhelming demand, further threatening the supply of workers on Burj Dubai and other Dubai construction projects. As of June 17, 2008 there are 7,500 skilled workers employed in the construction of Burj Dubai.
The silvery glass-sheathed concrete building will give the title of Earth's tallest free-standing structure to the Middle East—a title not held by the region since 1311 AD when Lincoln Cathedral in England surpassed the height of the Great Pyramid of Giza, which had held the title for almost four millennia.
The decision to build Burj Dubai is reportedly based on the government's decision to diversify from a trade-based economy to one that is service- and tourism-oriented. According to officials, it is necessary for projects like Burj Dubai to be built in the city to garner more international recognition, and hence investment. "He wanted to put Dubai on the map with something really sensational," said Jacqui Josephson, a tourism and VIP delegations executive at Nakheel Properties.