Thornton Tomasetti performed structural design for the modernization of a historic building and the addition of 120,000 square feet of office space that will serve as internal swing space during the renovation. The building, constructed between 1927 and 1932, is listed on the National Register of Historic Places and houses the Department of Commerce Headquarters, the White House Visitor’s Center, and the National Aquarium.
New courtyard infill structures will feature green roofs, advancing the project goal of LEED Silver certification. The 1.8-million-square-foot, $600 million project is programmed in eight phases – subject to congressional funding – with an estimated completion date of 2020. Design included structural modifications to support new mechanical equipment, shafts, stairs and elevators. The project also involved analysis and design for seismic bracing of roof parapets.
Preliminary design was performed for a relocation of the National Aquarium to the building’s south side where a new sunken entrance facing Constitution Avenue will feature a large salt-water tank visible from the National Mall.
Thornton Tomasetti completed structural design for all phases and construction administration for phases one and two.