About Burj khalifa 

Dubai's Burj Khalifa was formerly known as the Burj Dubai before its inauguration in 2010. At 829.8 meters (2,722 feet, a little over half a mile) in height, and with a roof height (including a 244 meter spire) of 828 meters (2,717 feet), this has been the world's tallest structure and building since it was completed in 2009, surpassing Taipei 101 in the standings.

The exterior of the Burj Khalifa was completed in 2009, five years after its construction began. Most of the building's structure is made of reinforced concrete, though some structural steel comes from the Palace of the Republic in East Berlin, the former East German parliament. As part of a new development called Downtown Dubai, the building was opened in 2010.

As the centerpiece of a mixed-use development of vast dimensions, it is designed to stand out. Dubai's government decided to build the building in order to diversify its economy away from oil, as well as gain international recognition. The Burj Dubai was initially named Burj Dubai but was renamed in honour of the ruler of Abu Dhabi and president of the United Arab Emirates, H.H Sheikh Khalifa bin Zayed Al Nahyan. In addition to being the tallest building in the world, the building broke numerous height records.

Adrian Smith, whose firm designed the Willis Tower and One World Trade Center, designed the Burj Khalifa. The architect was supervised by NORR Group Consultants International Limited and the engineer was from Hyderabad Consulting. In the Great Mosque of Samarra, for example, the design is based on Islamic architecture. Y-shaped tripartite floor geometry is designed to optimize hotel and residential space. Buildings with wings and a buttressed central core are supported at their height. Although this design was inspired by Tower Palace III, Burj Khalifa utilizes vertical transportation with the exception of egress stairs in each of its wings. Furthermore, the structure is protected with a cladding system that will withstand the hot summer temperatures in Dubai. It contains a total of 57 elevators and 8 escalators.

It is the centerpiece of a large-scale, mixed-use development which includes 30,000 homes, 9 hotels, 3 hectares of parkland, 19 residential skyscrapers, the Dubai Mall, and the 12-hectare artificial Burj Khalifa Lake.

world records :

• Tallest existing structure: 829.8 m (2,722 ft) (previously KVLY-TV mast – 628.8 m or 2,063 ft)
• Tallest structure ever built: 829.8 m (2,722 ft) (previously Warsaw radio mast – 646.38 m or 2,121 ft)
• Tallest freestanding structure: 829.8 m (2,722 ft) (previously CN Tower – 553.3 m or 1,815 ft)
• Tallest skyscraper (to top of spire ): 828 m (2,717 ft) (previously Taipei 101 – 509.2 m or 1,671 ft)^[20]
• Tallest skyscraper to top of antenna: 829.8 m (2,722 ft) (previously the Willis (formerly Sears) Tower – 527 m or 1,729 ft)
• Building with most floors: 163 (previously world trade center – 110)
• World's highest elevator installation (situated inside a rod at the very top of the building)^[
• World's longest travel distance elevators: 504 m (1,654 ft)
• Highest vertical concrete pumping (for a building): 606 m (1,988 ft)
• world's tallest structure  that includes residential space
• World's highest installation of an Aluminium and glass façade: 512 m (1,680 ft)
• World's highest nightclub : 144th floor
• World's highest resturant (At mosphere): 122nd floor at 442 m (1,450 ft) (previously 360, at a height of 350 m (1,148 ft) in CN Tower)
• World's highest New year display of fireworks 
• World's largest light and sound show staged on a single building.