The Burj Khalifa is a megatall skyscraper in Dubai, United Arab Emirates. Designed by Skidmore, Owings & Merrill, it is the world's tallest structure, with a total height of 829.8 m and a roof height of 828 m (2,717 ft). It has also been the tallest building in the world since its topping out in 2009, surpassing Taipei 101, which had held the record since 2004.