Chicago Architecture Info

The Aon Center

Formerly known as Amoco Building
Standard Oil Building
200 East Randolph Street
Chicago, Illinois 60601
Basic Information
Designed by Edward Durell Stone & Associates and Perkins and Will Corporation
Cost $120,000,000
Type Skyscraper
Floors: 83
Maximum height 1,136 feet/341 meters
Neighborhood: The Loop
More Information
  • Stories above ground: 83
  • Stories below ground: 5
  • Rentable floor space: 2,700,000
  • At the time of its completion, this was the tallest building in Chicago.
  • At the time of its completion, this was the fourth-tallest building in the world.
  • The building's original marble facade was from Carrara, the same Italian quarry used by Michaelangelo for his masterpiece "David."
  • This building is connected to the city's underground pedestrian tunnel system.
  • This was one of the filming locations for the 2011 movie Transformers 3.
  • 1972: Construction completed.
  • 1973: The Sears Tower surpasseed this building as the tallest building in Chicago.
  • 1974: A slab of the marble facade came off the building and plunged through the roof of the Prudential Center Annex.
  • 1989-1992: All 43,000 marble panels comprising the building's facade were replaced with granite from North Carolina. The marble panels were buckling and coming loose because of the harsh Chicago winters. It cost between $60- and $80,000,000 to replace all the stone.
  • November, 1991: A routine inspection found that two steel columns in the building's lobby had to be reinforced. The Chicago Tribune reported that although building officials say there is no danger, additional steel plates are welded to the columns in question.
  • 1998: This building was sold. The exact price was never made public, but estimated to be between $430,000,000 and $440,000,000.
  • January 1, 2001: The building's name was changed to Aon Center.
  • May, 2003 : The Aon Center was sold for $465,000,000.00.
  • March, 2007: A plan emerged to convert the top 13 stories of this tower to residential apartments or condominiums.
  • September, 2010: This building was named #20 on Chicago Magazine's list of the Top 40 Buildings in Chicago.
  • July, 2015: This building was bought by Piedmont Office Realty Trust for $712 million.