formerly burj dubai. renamed burj khalifa in honor of sheikh khalifa bin zayed bin sultan al nahyan, president of the united arab emirates (UAE). the building officially opened january 4, 2010.
above: from the spire, mid 2008
above: The tower is being constructed by a South Korean company, Samsung Engineering & Construction  which built the Petronas Twin Towers and the Taipei 101. The tower is designed by Skidmore, Owings and Merrill, who also designed the Sears Tower in Chicago and the Freedom Tower in New York City, among numerous other famous high-rises. The building resembles the bundled tube form of the Sears Tower, but is not a tube structure.
The design of Burj Dubai is ostensibly derived from the patterning systems embodied in Islamic architecture, with the triple-lobed footprint of the building based on an abstracted version of the desert flower hymenocallis native to the region. 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.
The renamed Burj Khalifa marks the first time since the Middle Ages, when Europe’s Gothic cathedrals rose taller than the Great Pyramid of Egypt, that the world’s tallest building has been located in the Middle East.
* Tallest skyscraper to top of spire: 828 m (2,717 ft) (previously Taipei 101 – 509.2 m (1,671 ft))
* Tallest structure ever built: 828 m (2,717 ft) (previously Warsaw radio mast – 646.38 m (2,121 ft))
* Tallest extant structure: 828 m (2,717 ft) (previously KVLY-TV mast – 628.8 m (2,063 ft))
* Tallest freestanding structure: 828 m (2,717 ft) (previously CN Tower – 553.3 m (1,815 ft))
* Building with most floors: 160 (previously Willis Tower – 108)
* World’s highest elevator installation
* World’s fastest elevators at speed of 64 km/h (40 mph) or 18 m/s (59 ft/s) (previously Taipei 101 – 16.83 m/s)
* Highest vertical concrete pumping (for a building): 606 m (1,988 ft) (previously Taipei 101 – 449.2 m (1,474 ft))
* Highest vertical concrete pumping (for any construction): 606 m (1,988 ft) (previously Riva del Garda Hydroelectric Power Plant – 532 m (1,745 ft))
* The first world’s tallest structure in history to include residential space
* Highest outdoor observation deck in the world (124th floor)
* World’s highest mosque (located on the 154th floor)
* World’s highest installation of an aluminium and glass façade, at a height of 512 m (1,680 ft)
* World’s highest swimming pool (76th floor)