151 North Franklin vs BMO Tower

Comparing the 151 North Franklin and the BMO Tower is interesting because they both stand in Chicago, IL, and were completed within 3 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 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 151 North Franklin reaches 600ft (183m) with 36 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 151 North Franklin and the BMO Tower 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 John Ronan Architects 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 151 North Franklin and the BMO 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.

Both towers provide significant parking capacity, with 151 North Franklin offering 34 spaces and the BMO Tower offering 324.

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

The 151 North Franklin uses a Framed Tube In Tube structural system, which combines a strong central core with a perimeter tube of columns, while the BMO 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.