Every Web Page About the Aon Center is About to Become Wrong

If you’re a fan of Wikipedia, the wannabe encyclopedia that’s the equivalent of asking a bunch of strangers at a bus stop to do your homework, it will soon need to be updated.  Along with the 8,643 other web sites that catalog skyscraper heights.

Aon Center from the ground up.

Right now, the Aon Center’s “architectural height” is 1,136 feet.  That means to the top of the mechanical room that hides all of the HVAC equipment.  That space is going to be altered to make way for a new “observatory ride,” which according to city documents, will raise the height of the building 34 feet to 1,170 feet and six inches.

Measuring the height of a skyscraper is like inviting your drunk uncle to Thanksgiving dinner: There’s always going to be an argument.  Some people may not want to measure to the top of the HVAC room.  They may want to go with the height of the new glass elevator, which goes all the way down to the same height as the main entrance.  OK, if that’s how you roll, then you’re talking about a 48-foot height increase to 1,184 feet.

Aon Center expected measurements (Base image courtesy of 601W Companies)

Aon Center expected measurements (Base image courtesy of 601W Companies)

Either way, this is a good test to see if the web site where you get your information is on the ball, or has been sold to a guy in California who thought he was going to make a million bucks in “passive income” off of it but then just let it rot until it finally was taken over by hackers and everything you worked on for ten years disappeared into the ether.  Not that I’m bitter.

Diagram of the Aon Center renovation

Diagram of the Aon Center renovation

The part that the web sites won’t have to update is the number of floors in the Aon Center.  Unless your drunk uncle stumbles about of the bathroom with one of the good towels and points out that while the top floor of the stately skyscraper is still labeled “83,” there is a curious floor 82.5 in the renovation plans drawn up by SCB, and he’s been counting since he was five years old and knows that 81… 82… 82.5… 83 means there will actually be 84 floors at the Aon Center.

It’s at this point that you refill your uncle’s dinner plate with more Thanksgiving turkey, refill his tumbler with Wild Turkey, sit him in front of the Redskins/Cowboys game, and let Captain Tryptophan enforce domestic harmony.

Meanwhile, you head back to the kitchen and “accidentally” knock the green bean casserole into the trash can because you were daydreaming about these other interesting facts from the Aon Center filing:

  • There will be a new reflecting pool on the east side of the building.
  • Harry Bertoia’s sound sculpture honoring the Illinois prairie has to be moved to make way for the visitor’s pavilion.  In the SCB diagram, it appears to be moving to the same location as the new reflecting pool, which would actually be pretty cool, if we’re reading the diagrams right.
  • There are spaces set aside in the visitor pavilion’s LL1 and LL3 for “future attractions.”
  • There will be a bus lobby on LL3.
  • Mechanical penthouse roof height: 1,170 ½ feet.
  • Elevator tower height: 1,184 feet, 2 ½ inches.
  • Pavilion height: 23 to 28 feet.  It slopes.

Location: 200 East Randolph Street, The Loop

Author: Editor

Editor founded the Chicago Architecture Blog in 2003, after a long career in journalism. He can be reached at chicagoarchitectureinfo@gmail.com.

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