CS Associates, Inc.
CS Associates, Inc. ProjectsCS Associates, Inc. Projects


Hoffman Estates, Illinois

AT&T Center is a four-story corporate headquarters building located in Hoffman Estates, Illinois. The office building is the focal point of a large office campus designed for AT&T by Lohan Associates, Inc. The main building, with overall dimensions of approximately 1,150 feet by 550 feet, contains nearly 1.3 million square feet of office space and support facilities.

Accommodation of thermal movements is critical in buildings of this size. Four expansion joints create five building segments along the 1150 feet of length. Expansion joints are also employed at each end of the structure where supported walkways connect the office building to parking structures.

An expansive skylight system and a structurally unique suspended walkway system serve as a network to unify the structure. The third and fourth floor walkway systems are suspended from the building columns in lightwells by a series of stainless steel rods. Vibration was a primary concern in the design of the walkways and is dampened by a 9 1/4" concrete walkway deck.

The skylight system, including the main dining area (126 feet x 90 feet) is supported by architecturally exposed structural steel. The skylight system extends the full building length as well as connecting the north and south wings with the main building spine.

Variable depth built-up girders spanning 48 feet with 25-foot cantilevers support the floor and roof levels of the parking structure walkways. These architecturally exposed structural steel "bridges" connect the main building to adjacent parking structures.

C S Associates' services included structural planning, analysis and design, computer modeling, preparation of contract documents and specifications and field observation. The building's overall dimensions as well as several unique features presented a structural engineering challenge for the office of C S Associates, Inc.

Architect: Lohan Associates, Chicago, Illinois
Developer: LaSalle Partners