The world’s tallest building opens in DubaiAT 828 metres (2,717 feet), the Burj Khalifa, which opened on Monday January 4th, dwarfs Taipei 101, which was previously the tallest tower anywhere, by 320 metres. The tower has more than 160 floors and cost some $1.5 billion. It is in danger, however, of being seen as the height of folly.