Located at the historic entrance to the Harry S. Truman Building at the U.S. Department of State Headquarters in Washington, DC, the U.S. Diplomacy Center (USDC) occupies 20,000 sf. Vanderweil provided mechanical, electrical, plumbing, and energy modeling design services for this two-story space designed to LEED Silver^®. The USDC hosts special events for the Department of State and includes three exhibition areas, a museum, a 60-seat theater, underground cafe, bookstore, and gift shop. A large skylight allows visitors to view the historic facade of the Truman Building from inside the pavilion, which required significant coordination with the architect to meet project energy design goals.