Within a three-week period, Adrian Smith sketched out the original designs that would eventually become the tallest building in the world, the Burj Khalifa. In the early 2000s, he was approached by Emaar Properties, the real estate company that developed the skyscraper. “They wanted to ask us about our experience with supertalls,” Smith tells AD. At the time, he was working at Skidmore, Owings & Merrill (SOM) and had designed…