Clark renovated the Harry S. Truman Building in Washington, DC as part of the GSA's Phase 1C Modernization project. The Harry S. Truman Building is home to the U.S. Department of State.

Clark demolished the interior of the building and complete hazardous material abatement. The building’s historic façade was reinforced with structural steel and existing windows was replaced with blast-resistant glass. Working with the GSA, as well as architect and engineer, Westlake Reed Leskosky, the team also provided progressive collapse mitigation, improved the core architectural finishes, and upgraded all mechanical, electrical, plumbing, communication, fire protection, circulation, and security systems.

Clark’s scope of work also included a 300,000 square-foot interior tenant fit-out of the space. Office areas were constructed based on the State Department’s criteria and included collaborative space with demountable partitions. The team also constructed ADA compliant corridors and restrooms.