One South Dearborn

Chicago, Illinois

Square Feet: 850,000

Chicago is a city of plazas that are uniquely organized on alternating blocks along Dearborn from the Daley Center to the Federal Plaza.  In that this building is similarly on the same street and is diagonally across the street from the central plaza created by the Bank One building, the design began with a concern about the spatial relationships created by these sequential plazas.  In creating a plaza at the front of One South Dearborn, another civic room is created but in this case unique in that the walls of the room are made up of the surrounding buildings as much as the new tower.  The Bank tower to the west is monolithic as an elevation in the east west direction and overwhelming to the pedestrian which this new plaza seeks to modify.  To the north is a former department store and to the south the celebrated Inland Steel building.  As an Architectural icon in the heart of Chicago, the Inland building was not only an apex of the mid century modern office buildings as well as the site of Mr. Keating's own early history in working for SOM.  Unique in both form and materials, with its shining stainless steel and solex glass, it remains an important building today.  Structurally cantilevered on both the north and the south, this new plaza will provide the northern facade a view and a role in the city for the first time.

The new One South Dearborn project creates a strong skyline image as well as a major plaza for the city.  The tower meets the skyline with an extended curtain-wall of textured glass that provides both a screen for the mechanical elements on the top of the building and a source of illumination through backlighting during the day.  Within this screen wall is an aperture consisting of a balcony for the two top floors of meeting rooms and a frosted glass screen above.  This aperture is aligned with the lobby entry on the plaza and is also inclusive of a refinement to the curtain-wall in the first 19 floors to visually align with the Inland Steel building. It is envisioned that the plaza, one of several along Dearborn Street, will feature cafe seating including 40 ft trees.

The design philosophy is rooted in the long history of Mr. Keating's partnership with SOM and his years in the Chicago office of that firm within the neighboring building, Inland Steel.  This and other buildings have created the City of Chicago as the paragon of structural expressionism which, in turn, is the primary urban fabric.  The next major tower was conceived to embrace and extend the language of this history.  Working within the strict budgetary confines of the developer, the design adapts the proportions and rhythm of the neighboring building while incorporating it as if it was always a part of the site in a two building complex.  Working with a new high performance glass and a sophisticated unitized curtain wall, the esthetic is achieved through the interplay of the building skins and is terminated by extending the skin beyond the roof line and manipulating it to become a major icon it the skyline.


The schedule of the construction was greatly enhanced to achieve the major tenants move-in needs within 24 months by building all the parking above ground.  This was achieved by the design response to incorporate the parking into the building base as a feature of glass and granite.

Because of the parking located within the tower, the design took advantage of the lack of basements and accommodated mature trees planted in earth rather than the usual trees in planters on a plaza.  This has become a very welcome addition to the city and the plaza.  The lobby glows to the street by a means of various glass elements that are internally lighted and extended as a concept both inside and outside the tower.