PEOPLE: architectural/engineering firm of record, Seal Engineering Inc., Alexandria, Va.; landscape architect, American University, Washington; general contractor, Verrazano Contracting Inc., Worcester, Pa.; and installer, Vatica Contracting, Washington

GREEN POINTS: When designing the 880-square-foot (82-m2) roof, David Fyffe, P.E., a principal at Seal Engineering Inc., wanted to prove the desirability of installing a green roof as a retrofit. Because the sedum was only 4 inches (102 mm) deep, only shallow plants were used. Twelve sedum plant types were chosen for their low height, color, texture and variety, resulting in an overall look similar to a tapestry. The waterproofing assembly consisted of a 215-mil-thick rubberized asphalt membrane, polyester reinforcement, styrene-butadiene-styrene protection course, root barrier, drainage and water-retention mat, filter fabric and insulation.

PROJECT PROVIDED BY BARRETT CO. / MILLINGTON, N.J. / WWW.BARRETTROOFS.COM