Burj Khalifa with Smith's attempts to make the crown more slender. The building opened on 4 January 2010. The tower was designed by Skidmore, Owings and Merrill (SOM), which also designed the Willis Tower (formerly the Sears Tower) in Chicago and the One World Trade Center in New York City. Burj Khalifa uses the bundled tube design of the Willis Tower, invented by Fazlur Rahman Khan. Due to its tubular system, proportionally only half the amount of steel was used in the construction, compared to the Empire State Building. Khan's contributions to the design of tall buildings have had a profound impact
Grant Thornton Tower and Exchange Commission filings. Grant Thornton Tower Grant Thornton Tower (formerly Chicago Title & Trust Center, 161 North Clark and sometimes Chicago Title Tower) is an office tower located in Chicago designed by the firm Kohn Pedersen Fox Associates. Before completion in 1990 the twin tower design was awarded The Chicago Athenaeum's "Best Building" Architecture Award, the award was received by one of the lead designers Kevin Flanagan. (view PLP Architects). The fifty-storey building rises 756 feet (230 m) in the Loop and was completed in 1992, on the site of Chicago's Greyhound Bus Station. Previously, a structure at 111