Winnipeg has a building with a very rare and unique design. The Canadian Grain Commission Building on Main near Portage has a bulge that makes the top floors wider than the bottom floors. According to Wikipedia it is called “Setfront design.”

Ernest J. Smith of Smith Carter was the principal architect of the Grain Commission’s current headquarters, nicknamed the “mushroom building”, the structure itself is a notable example of a Canadian skyscraper displaying Brutalist elements. The building’s “extended cap” was designed because of a space needed between the upper and lower floors for specialized mechanical equipment used to transport grain to an upper-level flour mill and test brewery. Smith remarked on the challenges involved:

Mixing two different functions in a vertical building is difficult. Normally construction would be separated horizontally. In this case, we worked out two separate modules for offices and lab space, [and] found we needed greater depth in the lab and rationalized the present form.

I surf tall building websites quite often. Mainly Skyscraperpage.com. In searching cities across North America and the world I have found only one other building with this setfront design. 

It’s in Denver, 707-17th street. It has 42 stories compared to the Grain Commission at 17. Grain Commission is 220 feet tall while 707-17th is 550 feet. Only two buildings. And one in The Peg.

707-17th: