The U.S. General Services Administration on Aug. 14 let its largest stimulus-funded project so far, a $435.4-million design-build contract for the new U.S. Coast Guard headquarters building in Washington, D.C. Clark Construction Group of Bethesda, Md., led the winning team, joined by St. Louis-based HOK, which will provide interior designs, landscape architecture, construction documents and administration. The Washington office of WDG Architecture is architect-of-record. Chicago-based Perkins+Will created preliminary designs and bridging documents for the 1.2 million-sq-ft building, which will aim for a LEED Silver rating. The headquarters, along with a 1,000-car parking garage, will be built on the new 4.5 million-sq-ft Homeland Security campus at the former St. Elizabeth’s Hospital site. Project funding includes $162 million from the American Recovery and Reinvestment Act. Groundbreaking is scheduled for September, with completion in 2013.