Two Prudential Plaza vs Grant Thornton Tower

Comparing the Two Prudential Plaza and the Grant Thornton Tower is interesting because they both stand in Chicago, IL, and were completed within 2 years of each other, but they were designed by different architects.

This offers a unique glimpse at how rival designers approached projects in the same city during the same era.

The Two Prudential Plaza is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 994ft (303m) with 64 floors above ground, while the Grant Thornton Tower reaches 755ft (230m) with 50 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 Two Prudential Plaza and the Grant Thornton Tower were designed in line with the aesthetic conventions of the Postmodernism style.

The Grant Thornton Tower was designed at a moment when the Postmodernism style was already in decline, making it more of a lingering expression of the movement. In contrast, the Two Prudential Plaza was built when the style still carried greater cultural weight.

Both the Two Prudential Plaza and the Grant Thornton Tower were designed to serve as commercial towers, and that has remained their main use since their completion, serving similar roles in the urban fabric.

The Two Prudential Plaza also provides 325 parking spaces.

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

The Two Prudential Plaza uses a Framed Tube In Tube structural system, which combines a strong central core with a perimeter tube of columns, while the Grant Thornton Tower uses a Frame system, that relies on a regular grid of columns and beams to sustain its weight.

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.