Accenture Tower/ Chicago, Illinois/ 1987
Type: Infrastructure, Mixed-Use, Office, Transportation
Size: 1,600,000 sq ft / 148,640 sq m
Height: 38 floors
Status: Completed 1987
Previously Named: Citigroup Center, Northwestern Atrium Center
Recognition: Structural Engineering Association of Illinois; BOMA Chicago Chapter Building of the Year Award
Northwestern Atrium Center incorporates a street-level retail arcade and a 38-floor office tower atop a major commuter train hub at the edge of Chicago’s Loop. Reinforcing urban connectivity through a sequence of multi-story atriums, which enhance the commuter traffic flow to the train platforms, the building is full of light and spatial excitement in which the office floors also share.
On the street and track levels, 85,000 square feet of terminal facilities serve the requirements of a modern-day commuter terminal. The atriums create a public amenity of 30,000 square feet of open space, with ceilings rising to heights of 80 feet. The office tower is served from a sky lobby one floor above the track level.
Floor sizes within the tower vary from 50,000 square feet in the lower levels to 30,000 square feet at the upper extents. This formal concept is driven by passive strategies for energy efficiency; the atrium spaces bring light deep within the building without the penalty of added exterior heat loss or gain by reducing the exterior exposure.
The form of the tower reflects the symmetry of the scheme and the varying floor sizes. Composed of three extruded shapes shifting against each other, these forms come together at the base and separate at the top. The smooth, streamlined curves create a formal relationship to the trains beneath and evoke machine-like associations.
