Added by on 2017-03-20

Stay on top of the Greenroof & Greenwall World by subscribing here: In 2006, the American Society of Landscape Architects demonstrated their commitment to sustainable design by incorporating a greenroof atop their Washington, DC. Headquarters. Michael Van Valkenburgh Associates led the design process, collaborating with Conservation Design Forum to develop the design and specifications for the approximately 3,000 square-foot roof surface. The plan was to create a landmark demonstration project, and a primary focus was to make greenroofs more mainstream and demonstrate that landscape architects play a central role in green roof design and construction. The ASLA roof contains six distinct greenroof conditions, representing extensive, semi intensive, and intensive systems ranging in growing media depths of 3 to 21 inches. North and South “waves” dominate the design, with a central viewing platform with seating areas for the public, and a stairwell structure. The American Hydrotech Garden Roof® Assembly was chosen for the greenroof system, and to effectively confine and stabilize the growing media on the sloped waves, GardNet™ was installed. With plants and consulting provided by Emory Knoll Farms, the plant palette has evolved over the years. The South Wave now consists mostly of sedum and Prickly Pear cactus and the North Wave is covered with 50% sedum, with thread-leaf tickseeds, chives, nodding onions, black-eyed Susans, Virginia wild rye, silver king, and butterfly milkweed. Fragrant sumacs cover the new staircase, and sedums grow profusely under the grates. Monitored from July 2006 to May 2007, the living roof prevented 27,500 gallons of stormwater – or 77% of all precipitation – from flowing into D.C.’s overburdened sewer system, and it continues to keep the roof temperature as much as 43.5 degrees F cooler than neighboring conventional black roofs in the summer as well as reducing building energy use by 10% over […]

Leave a Reply

Your email address will not be published. Required fields are marked *