Specialty Building

Several innovations in sustainable, lean construction techniques have been gaining broad adoption. A recent example the new, four-story legal office building and courtroom at Fort Belvoir, Virginia, spearheaded by the U.S. Army Corps of Engineers for its client, the U.S. Army Legal Service Agency Administration. Aiming for LEED Gold, the project's design/build team led by architects at Perkins+Will and BCRA Inc. and the contractor Suffolk Construction focused on methods for achieving a high-quality, durable building that could be constructed within a short, 12-month fast-track schedule.

On a design level, the building – called the BRAC 132 Army Administrative Facility – had to "express the permanency of the court system and the high ideals to which the military legal system adheres," according to Andrew Rashid, Perkins+Will’s science and technology market leader, Washington, D.C. Conceived in a brick finish to match the base’s buildings. At the same time, the team looked at ways to boost productivity and reduce waste while ensuring a high level of workmanship and quality, according to Chris Seveney of Suffolk Construction. "A project like this would typically carry a delivery schedule of 24 months, but it was given a congressionally mandated completion date of one year," says Seveney. "It was essential that the team use as many lean design-and-construction practices as possible."

Taking time to compare a variety of building approaches, the team considered using the novel composite system, SlenderWall, which combines a precast exterior panel with an integrated perimeter stud-wall system. The cladding could match the local brick finish and had punched window openings, with sections up to 26 feet wide to minimize visible joints. Filled with closed-cell foam insulation at 3.5 inches deep, the 169 discrete panels would also deliver high thermal performance of R-21 with a continuous air and moisture barrier.

SlenderWall also already had approvals for meeting the strict anti-terrorism criteria for security and blast-resistance as required for all new government buildings by the federal departments of Defense and Homeland Security.

It took only 14 days to enclose both buildings with the 10-foot-tall panels, according to Suffolk Construction, helping telescope the schedule. The use of the SlenderWall system further saved time by eliminating the need for an insulation contractor and carpenters for perimeter wall framing. This compares to the eight to 10 weeks normally for traditional brick veneer masonry, with two more weeks for the interior framing, and five days for closed-cell foam application.

The exterior, which combines a brick veneer finish with buff-colored banding and windowsills, matches the brick finishes used throughout the Virginia military base, yet projects the image of a modern office structure. The exposed precast concrete resists moisture intrusion thanks to an integral concrete admixture employed in the manufacturing process of all SlenderWall panels. "This project shows how the federal sector can think lean and smart in future projects," says Heidi Perham, NCARB, AICP, managing director with BCRA, which designed the interiors and later presented the project at the 2012 Design-Build Institute of America Federal Sector Conference in Arlington, Va.