71 South Wacker Building vs One Dalton Building

Comparing the 71 South Wacker Building and the One Dalton Building is compelling because they were both designed by Pei Cobb Freed & Partners, yet they stand in different cities (Chicago, IL and Boston, MA), and were completed a decade apart.

What this will allow us to see, is how the same firm's approach adapted to different places in different periods of time.

The One Dalton Building is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 748ft (228m) with 61 floors above ground, while the 71 South Wacker Building reaches 679ft (207.1m) with 48 floors above ground.

Despite being taller and having more floors, One Dalton Building has less total built-up area than 71 South Wacker Building.

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 71 South Wacker Building and the One Dalton 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 Pei Cobb Freed & 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.

The One Dalton Building follows a mixed-use model, combining residential and hotel. In contrast, the 71 South Wacker Building has remained primarily commercial.

The One Dalton Building incorporates a 5-star hotel with 215 rooms. More information is available at the official website.

The One Dalton Building offers 160 residential units.

The 71 South Wacker Building also provides 163 parking spaces.

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

The 71 South Wacker Building uses a Framed Tube In Tube structural system, which combines a strong central core with a perimeter tube of columns, while the One Dalton Building 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.