Park Tower at Transbay vs 155 North Wacker Building

Comparing the Park Tower at Transbay and the 155 North Wacker Building is compelling because they were both designed by Goettsch Partners , yet they stand in different cities (San Francisco, CA and Chicago, IL), and were completed more than 9 years apart.

What this will allow us to see, is how the same firm's approach adapted to different places at roughly the same time (9 years isn't that much time when it comes to urban context and architecture).

The 155 North Wacker Building is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 640ft (195m) with 45 floors above ground, while the Park Tower at Transbay reaches 604ft (184m) with 43 floors above ground.

155 North Wacker Building also offers more total built-up area, a total fo 1,384,991 sqf (128,670m²), which is about 581,294 sqf (54,004m²) more than what the Park Tower at Transbay offers.

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 Park Tower at Transbay and the 155 North Wacker 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 both Goettsch Partners and Goettsch Partners followed what was in many ways expected of them, producing designs that fit comfortably within contemporary architectural norms, rather than breaking with convention.

Both the Park Tower at Transbay and the 155 North Wacker 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.

Both towers provide significant parking capacity, with Park Tower at Transbay offering 117 spaces and the 155 North Wacker Building offering 163.

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

The Park Tower at Transbay uses a Frame structural system, which relies on a regular grid of columns and beams to sustain its weight, while the 155 North Wacker 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.