BMO Tower vs 155 North Wacker Building

Comparing the BMO Tower and the 155 North Wacker Building is particularly interesting because they share the same skyline in Chicago, IL, and were both designed by Goettsch Partners . However, they were completed more than 12 years apart.

This offers a unique perspective on how the architect's style and the city's architecture evolved over time.

The BMO Tower is clearly the larger tower of the two, both in terms of height and number of floors. It rises to 728ft (222m) with 51 floors above ground, while the 155 North Wacker Building reaches 640ft (195m) with 45 floors above ground.

BMO Tower also offers more total built-up area, a total fo 1,739,995 sqf (161,651m²), which is about 355,004 sqf (32,981m²) more than what the 155 North Wacker Building 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 BMO Tower 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 BMO Tower 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 BMO Tower offering 324 spaces and the 155 North Wacker Building offering 163.

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

The BMO Tower 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.