311 South Wacker Drive, the tallest concrete structure in the world at the time of its completion, connects office space with the public realm through its iconic winter garden.
The building was conceived as the first phase in a three-tower development on a South Wacker Drive site adjacent to the Sears Tower. A two-level, 85 ft glass-ceilinged winter garden provides a grand entrance for visitors. The cathedral-like space is supported by a steel structure influenced by the Chicago “L” tracks and bridges. A fountain and Raymond Kaskey’s bronze sculpture, “Gem of the Lakes,” are eye-catching centerpieces for the lobby and winter garden. The lower level of the winter garden was designed to connect via underground passageway to Union Station.
The façade of flamed Texas red granite, with polished strapping at the edges, serves as a visual expression of the structural frame. This pattern is denser at the lower three levels where it creates a distinctive base and anchor for the pedestrian. Horizontal strapping at the base along Franklin Street and the 13th and 46th floors joins the lower levels to the octagonal tower that rises out of the base of the building. At the top, the frame breaks away from the building, creating a Gothic framework of columns and beams. At the 51st floor, the tower breaks free to become a geometrically pure object; a large translucent glass cylinder and four surrounding glass cylinders glow at night and are recognizable from all directions on the skyline.
