Willis Tower’s was designed by architectural firm Skidmore, Owings and Merrill.

2,000 construction workers took part in building Willis Tower.

The building features a steel-framed bundled-tube construction method.

Willis Tower was the world’s tallest building until 1998.

12th tallest building in the world.

2nd tallest building in North American.

1,450 feet high (443 meters) and 110 stories tall.

76,000 tons of steel was used.

Combined weight of the building is 222,500 tons.

Tower has 16,100 bronze-tinted windows

104 elevators moving 1,200 feet per minute.

The structure was completed in May 1973

The construction cost about US$150 million, equivalent to $870 million in 2022 dollars.

As part of the building's recycling program, tenants recently recycled over 2,103 tons of paper, aluminum, glass, & plastic and construction waste annually.