Acting with delegated authority from GSA as the Historic Preservation Officer, KCCT preserved the most architecturally and historically significant spaces of the landmark building and modernized other parts of the remaining portions, renovating about 80% of the space for new office use. The preservation design restored the original finishes and fixtures of the East Entrance lobby, Art Deco-style elevator lobbies, a reception room and high-ceiling executive offices, including the historic office of Secretary of State George C. Marshall. We also converted a former mechanical courtyard into a state-of-the-art auditorium and conferencing center, and added a new computer center, while integrating perimeter and technical security features throughout the facility.