Photo by Atlantic Archives
Project team erected the Savannah, Ga., building atop an existing underground parking garage.

Initiated by the General Services Administration's need for new space for the Office of the United States Attorney, Southern District, the biggest challenge facing the contractors erecting Savannah's Cay Building was to overcome the downtown site's development history.

Prior to this project, the owners of the site, John Cay and Whitaker Street Associates, had granted the city of Savannah the right to construct and operate a 1,000-space, below-ground parking garage, with the requirement the structure be engineered to support a future building.

Despite that requirement, the garage presented weight limitations to the team building the six-story, 65,000-sq-ft office facility. Since the new building could not bear on the garage, the new structure rests on 32 columns extending into the subterranean parking vault. A series of steel angles and large cantilevered sections of slab support the building veneer, transferring structural load to the columns.

In an effort to keep weight off the slab, crews with New South Construction Co. installed structural foam—sometimes 2 ft thick—below the slabs. Construction of one 30-ft x 30-ft bay required that its slab span four columns on its corners and not sit on the slab just inches below. To achieve that goal, crews formed the slab atop a bed of sand, and, after the concrete hardened, pressure-washed the sand out.

Additionally, the team worked closely with the Savannah Historic Board of Review to ensure the project complied with the city's historic preservation guidelines. The building meets federal standards and includes blast-resistant windows. The building's coastal location mandated that the windows comply with hurricane specifications.

Project Team

Project Developer: Holder Properties, Atlanta

Owner: General Services Administration, Atlanta

Architect: Sottile & Sottile, Savannah, Ga.

General Contractor: New South Construction Co., Atlanta

Structural Engineer: Thomas & Hutton, Savannah