Burj Khalifa known as Burj Dubai prior to its inauguration, is a skyscraper in Dubai, United Arab Emirates, and the tallest man-made structure ever built, at 828 m (2,717 ft). Construction began on 21 September 2004, with the exterior of the structure completed on 1 October 2009. The building officially opened on 4 January 2010, and is part of the new 2 km2 (490-acre) flagship development called Downtown Dubai at the 'First Interchange' along Sheikh Zayed Road, near Dubai's main business district.
The tower's architecture and engineering were performed by Skidmore, Owings, and Merrill of Chicago, with Adrian Smith as chief architect, and Bill Baker as chief structural engineer. The primary contractor was Samsung C&T of South Korea.In June 2010, Burj Khalifa was the recipient of the 2010 Best Tall Building Middle East & Africa award by the Council on Tall Buildings and Urban Habitat.
The total cost for the project was about US$1.5 billion; and for the entire 'Downtown Dubai', US$20 billion. In March 2009, Mohamed Ali Alabbar, Chairman of the project's developer, Emaar Properties, said office space pricing at Burj Khalifa reached US$4,000 per sq ft (over US$43,000 per m2) and the Armani Residences, also in Burj Khalifa, sold for US$3,500 per sq ft (over US$37,500 per m2).
The project's completion coincided with the global financial crisis of 2007–2010, and with vast overbuilding in the country, led to high vacancies and foreclosures. With Dubai mired in debt from its huge ambitions, the government was forced to seek multi-billion dollar bailouts from its oil-rich neighbor Abu Dhabi. Subsequently, in a surprise move at its opening ceremony, the tower was renamed Burj Khalifa, said to honor the UAE President, Khalifa bin Zayed Al Nahyan for his crucial support.
Burj Khalifa has been designed to be the centrepiece of a large-scale, mixed-use development that will include 30,000 homes, nine hotels such as The Address Downtown Dubai, 3 hectares (7.4 acres) of parkland, at least 19 residential towers, the Dubai Mall, and the 12-hectare (30-acre) man-made Burj Khalifa Lake.
The building has returned the location of Earth's tallest free-standing structure to the Middle East — where the Great Pyramid of Giza claimed this achievement for almost four millennia before being surpassed in 1311 by Lincoln Cathedral in England.
The decision to build Burj Khalifa is reportedly based on the government's decision to diversify from an oil-based economy to one that is service- and tourism-oriented. According to officials, it is necessary for projects like Burj Khalifa to be built in the city to garner more international recognition, and hence investment. "He (Sheikh Mohammed bin Rashid Al Maktoum) wanted to put Dubai on the map with something really sensational," said Jacqui Josephson, a tourism and VIP delegations executive at Nakheel Properties.
Burj Khalifa compared to some other well-known tall structures.
There are unconfirmed reports of several planned height increases since its inception. Originally proposed as a virtual clone of the 560 m (1,837 ft) Grollo Tower proposal for Melbourne, Australia's Docklands waterfront development, the tower was redesigned with an original design by Skidmore, Owings and Merrill (SOM) discussed below. Marshall Strabala, an SOM architect who worked on the project until 2006, late 2008 said that Burj Khalifa was designed to be 808 m (2,651 ft) tall.
The design architect, Adrian Smith, felt that the uppermost 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 current 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.
Emaar Properties announced on 9 June 2008 that construction of Burj Khalifa was delayed by upgraded finishes and would be completed only in September 2009. An Emaar spokesperson said "The luxury finishes that were decided on in 2004, when the tower was initially conceptualized, is now being replaced by upgraded finishes. The design of the apartments has also been enhanced to make them more aesthetically attractive and functionally superior." A revised completion date of 2 December 2009 was then announced. However, Burj Khalifa was opened on 4 January 2010.
A Hymenocallis flower showing six spokes, as pattern for the three-lobed design
The tower is designed by Skidmore, Owings and Merrill, which also designed the Willis Tower (formerly the Sears Tower) in Chicago, Illinois and 1 World Trade Center in New York City, among numerous other famous high-rises. The building resembles the bundled tube form of the Willis Tower, but is not a bundle tube structure. Its design is reminiscent of Frank Lloyd Wright's vision for The Illinois, a mile-high skyscraper designed for Chicago. According to Marshall Strabala, an SOM architect who worked on the building's design team, Burj Khalifa was designed based on the 73-floor Tower Palace Three, an all-residential building in Seoul, South Korea. In its early planning, Burj Khalifa was intended to be entirely residential.
Subsequent to the original design by Skidmore, Owings and Merrill, Emaar Properties chose Hyder Consulting to be the supervising engineer. Hyder was selected for its expertise in structural and MEP (mechanical, electrical and plumbing) engineering. Hyder Consulting's role was to supervise construction, certify SOM's design, and be the engineer and architect of record to the UAE authorities. Emaar Properties also engaged GHD, an international multidisciplinary consulting firm, to act as an independent verification and testing authority for concrete and steelwork.
The design of Burj Khalifa is derived from patterning systems embodied in Islamic architecture. According to the structural engineer, Bill Baker of SOM, the building's design incorporates cultural and historical elements particular to the region. The Y-shaped plan is ideal for residential and hotel usage, with the wings allowing maximum outward views and inward natural light. The design architect, Adrian Smith, has said the triple-lobed footprint of the building was inspired by 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. There are 27 terraces in Burj Khalifa. 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. At its tallest point, the tower sways a total of 1.5 m (4.9 ft).
To support the unprecedented height of the building, the engineers developed a new structural system called the buttressed core, which consists of a hexagonal core reinforced by three buttresses that form the ‘Y' shape. This structural system enables the building to support itself laterally and keeps it from twisting.
The spire of Burj Khalifa is composed of more than 4,000 tonnes (4,400 ST; 3,900 LT) of structural steel. The central pinnacle pipe weighing 350 tonnes (390 ST; 340 LT) was constructed from inside the building and jacked to its full height of over 200 m (660 ft) using a strand jack system. The spire also houses communications equipment.
More than 1,000 pieces of art will adorn the interiors of Burj Khalifa, while the residential lobby of Burj Khalifa will display the work of Jaume Plensa, featuring 196 bronze and brass alloy cymbals representing the 196 countries of the world. The visitors in this lobby will be able to hear a distinct timbre as the cymbals, plated with 18-carat gold, are struck by dripping water, intended to mimic the sound of water falling on leaves.
The exterior cladding of Burj Khalifa consists of 142,000 m2 (1,528,000 sq ft) 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. Additionally, the exterior temperature at the top of the building is thought to be 6°C (11°F) cooler than at its base. Over 26,000 glass panels were used in the exterior cladding of Burj Khalifa. Over 300 cladding specialists from China were brought in for the cladding work on the tower.
An Armani Hotel, the first of four by Armani, occupies 15 of the lower 39 floors. The hotel was supposed to open on 18 March 2010 but after several delays the hotel finally opened the public on 27 April 2010. The corporate suites and offices were also supposed to open from March onwards but the hotel and observation deck remain the only parts of the building which are open.
The sky lobbies on the 43rd and 76th floors will house swimming pools. Floors through to 108 will have 900 private residential apartments (which, according to the developer, sold out within eight hours of being on the market). An outdoor zero-entry swimming pool will be located on the 76th floor of the tower. Corporate offices and suites fill most of the remaining floors, except for a 122nd, 123rd and 124th floor where the At.mosphere restaurant, sky lobby and an indoor and outdoor observation deck is located respectively. Burj Khalifa will receive its first residents from February 2010. They will be among the first of 25,000 people who will live there.
Burj Khalifa is expected to hold up to 35,000 people at any one time. A total of 57 elevators and 8 escalators are installed. The elevators have a capacity of 12 to 14 people per cabin, the fastest rising and descending at up to 18 m/s (59 ft/s). Engineers had considered installing the world's first triple-deck elevators, but the final design calls for double-deck elevators. The double-deck elevators are equipped with entertainment features such as LCD displays to serve visitors during their travel to the observation deck. The building has 2,909 stairs from the ground floor to the 160th floor.
The graphic design identity work for Burj Khalifa is the responsibility of Brash Brands, who are based in Dubai. Design of the global launch events, communications, and visitors centers for Burj Khalifa have also been created by Brash Brands as well as the roadshow exhibition for the Armani Residences, which are part of the Armani Hotel within Burj Khalifa, which toured Milan, London, Jeddah, Moscow and Delhi.