As part of the renovation and expansion of the Potomac Center building, the southern half of the existing concrete-framed structure was completed as Phase I of two phases. Potomac Center South houses the U.S. Department of Education and has eight levels above-grade and three levels of parking below. The existing space totaled approximately 250,000 gsf of occupied area plus 150,000 gsf of below grade parking. The project also included the addition of 220,000 sf of new office space.
The horizontal expansion added reinforced concrete bays to floors two through eight. The flat plate design of the expansion was similar to the original structure in order to allow for proper ceiling heights. The building was also expanded vertically by adding three steel-framed levels above the original roof level, plus a new roof and penthouse, bringing the building to its new size of 11 stories.
The new upper levels were designed of composite steel, using 12-inch deep beams and girders in 20-ft. bays in order to minimize the dead load added to the existing columns and foundations. Foundations were upgraded using mini-pile underpinning. The entire facade was replaced and the core re-worked to accommodate new MEP systems. Structural security features were also added to meet tenant and GSA requirements.