The Pentagon, U.S. Army Corps of Engineers
Washington DC
With no significant renovations in more than five decades, the historic Pentagon complex needed extensive rehabilitation to bring it into the 21st century.
South Terrace Addition
The new South Terrace is the first major addition to the historic Pentagon reservation. The addition was needed to provide safer access to the Pentagon for staff members. Located at the south facade, the structure consists of two elevated terraces. At the end of each bridge, stairs, escalators and elevators transport pedestrians from ground level to terrace level so that they can cross over loading dock traffic.
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HSMM designers selected building materials to match the existing Pentagon building. Portions of the terrace structure are clad in limestone, and architectural details from the Pentagon are repeated in the addition, including classical cornices, pilasters, lighting fixtures, and handrails. Because of the building's historic significance, the South Terrace design was reviewed by two key agencies in the National Capital Region: the National Capital Planning Commission and the Commission of Fine Arts. Both praised the design for meeting its design goal of improving accessibility while remaining sensitive to the existing architecture and historic character of the Pentagon.
Renovation of Wedge 1
HSMM designed the renovation of the first "wedge" of the building, encompassing 1.1 million SF on an accelerated schedule of 15 months. The $150 million renovation program created state-of-the-art office space and replaced all interior finishes and systems, including HVAC, electrical power, lighting, communications, and security systems. HSMM designers used 3D CADD technology to verify locations of the new systems in utility tunnels and service corridors. HSMM also designed the tenant fit-out for Wedge 1 office space.
Force protection and security improvements were key considerations, and HSMM designed blast-resistant upgrades for the building's exterior walls and windows. These design elements became extremely critical during the September 11 attack on the Pentagon and have been credited with saving many lives. The project received awards from the Washington Building Congress and from the Associated Builders and Contractors.
