Everett McKinley Dirksen U.S. Courthouse vs Aon Center

Comparing the Everett McKinley Dirksen U.S. Courthouse and the Aon Center is interesting because they both rise in Chicago, IL, yet they were conceived by two different design teams, Mies van der Rohe and Edward Durell Stone, and were completed at different points in time. They were finished more than 9 years apart.

This contrast within the same city allows us to see how different creative minds interpreted the evolving needs of Chicago across time.

Let's take a closer look!

The Aon Center is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 1135ft (346m) with 83 floors above ground, while the Everett McKinley Dirksen U.S. Courthouse reaches 384ft (117m) with 27 floors above ground.

Of course, each project may have faced different briefs or regulatory constraints, which we don't really know about and could also explain the outcome.

Both the Everett McKinley Dirksen U.S. Courthouse and the Aon Center were designed in line with the aesthetic conventions of the International Style style.

The Aon Center was designed at a moment when the International Style style was already in decline, making it more of a lingering expression of the movement. In contrast, the Everett McKinley Dirksen U.S. Courthouse was built when the style still carried greater cultural weight.

The Everett McKinley Dirksen U.S. Courthouse is primarily governmental, while the Aon Center is primarily commercial.

The Aon Center also provides 679 parking spaces.

The two towers rely on different structural systems, reflecting distinct engineering strategies.

The Everett McKinley Dirksen U.S. Courthouse uses a Frame structural system, which relies on a regular grid of columns and beams to sustain its weight, while the Aon Center uses a Framed Tube In Tube system, that combines a strong central core with a perimeter tube of columns.

Yet, when it comes to their facade, they both employed the same solution, a Curtain Wall facade.

A curtain wall is a non-load-bearing facade hung from the structural frame. It is anchored to floor slabs and transfers only its own weight and wind loads, allowing for sleek, glassy exteriors.