Ordinarily, a 2.4-million-sq-ft, highly complex construction project would be hard to overlook. As it nears completion in September, the new National Geospatial-Intelligence Agency’s East Campus at Ft. Belvoir, Va., has stayed largely under the radar, as its owner prefers.

The 2.4-million-sq-ft U.S. spy-agency complex is 90% done.

Within the U.S. Defense Dept., NGA provides geospatial images and data for national security, including the May 2 Osama Bin Laden raid. From site selection to operations, managing the 98-acre project in four years challenged the Corps of Engineers. “Given the tight schedule and NGA’s need to be closely engaged with every stage of the project, neither design-bid-build nor design-build would have worked,” says Corps program manager Michael Rogers. He says those approaches could have cost NGA the expertise of its design team, led by RTKL and KlingStubbins, which was well-versed in agency requirements.

Early contractor involvement—in this case, construction was advertised with a 15% design and awarded to a joint venture of Clark Construction Group and Balfour Beatty Construction at 35% in 2007—was the solution. Rogers says having builder input as design progressed “ensured we had good market-based information about cost implications of design choices.” Structural steel for the 2.2-million-sq-ft centerpiece building’s two 900 x 1300-ft wings was erected in eight vertical increments, speeding turnover of spaces for complex internal systems, including a chilled-beam heating-and-cooling system—one of the largest in the U.S. The exterior facade features curtain-wall and pre-cast elements with punched windows, a nod to NGA employees who did not want total isolation. Also included are a 150,000-sq-ft IT support center, a 100,000-sq-ft central utility plant and a 5,000-space garage. Security underscored all, from site access and material inspections to construction-activity monitoring.