What is the architectural height of Chicago's Willis Tower?
Answer
442.1 metres
Chicago’s Willis Tower has an architectural height of 442.1 metres.
Completed in 1973, the tower was designed by architect Bruce Graham and structural engineer Fazlur Rahman Khan for Sears, Roebuck & Co. Its bundled-tube structural system groups nine square tubes, allowing the building to withstand Chicago’s strong winds while using less material than a conventional frame.
The tower was originally called the Sears Tower and kept that name in common usage for decades. It was officially renamed Willis Tower in 2009 after the insurance company Willis Group Holdings moved into the building.
The 442.1-metre figure is the architectural height, measured to the top of the roof. Antennas extend higher, which is why sources may quote a different overall height. The tower’s Skydeck includes glass balconies projecting from the 103rd floor.