Epstein's Top 100 Projects: #55: 300 South Wacker

Today’s feature in our Top 100 Projects countdown is 300 South Wacker, a 35-story, 600,000-square-foot office building located in Chicago.

Coming in at no. 55 and completed in 1972, this 440-foot-tall Epstein-designed high-rise, which was an ode to Mies van der Rohe, was comprised of reinforced concrete and clad in bronze aluminum curtainwall with bronze tinted glass. The plaza level column, lobby walls and promenade was trimmed in Coldspring granite.

300 South Wacker’s unusually narrow site dictated a thin building that was only 69’ wide but 230’ long, presenting rather serious wind load problems. There were resolved through the careful placement of concrete shear walls between the elevator shafts.

The structure is a flat slab design and rests on concrete caissons extending to the hard-pan, approximately 70 feet below street level. 300 South Wacker was topped-out after one year of construction, making it one of Chicago's most rapidly constructed reinforced concrete buildings at the time. A typical 16,300-square-foot office floor was poured at the rate of a floor every three days!

Furthermore, the mechanical equipment was not only located in the penthouse, but also in the 19^th floor, which provided HVAC for the lower levels. This was a somewhat unique approach for the late 60s/early 70s design. In many cases, mechanical equipment was located in the basement and penthouse of a high-rise of this size. The placement of this equipment on the 19^th floor was dictated by a request for the basement to be used for underground parking for 300 South Wacker executives.