Salesforce Tower vs One Congress Building

Comparing the Salesforce Tower and the One Congress Building is an interesting exercise, because even though they are located in different cities (Chicago, IL and Boston, MA), both were designed by Pelli Clark & Partners and finished within in the same year. This gives us the chance to see how the same architect's ideas were expressed in different urban contexts almost simultaneously.

The Salesforce Tower is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 817ft (249m) with 57 floors above ground, while the One Congress Building reaches 646ft (197m) with 43 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 Salesforce Tower and the One Congress Building were designed in line with the aesthetic conventions of the Contemporary style.

At the time, this style was at the height of its popularity. So Pelli Clark & Partners followed what was in many ways expected at the time, producing designs that fit comfortably within contemporary architectural norms rather, than breaking with convention.

Both the Salesforce Tower and the One Congress Building 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 One Congress Building also provides 1160 parking spaces.

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

The Salesforce Tower uses a Frame structural system, which relies on a regular grid of columns and beams to sustain its weight, while the One Congress Building 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.