The Calhoun School celebrated the opening of its new Green Roof Learning Center on Tuesday, May 3, 2005. The Green Roof was part of a major expansion that added four floors to the school’s pre-existing building on the Upper West Side of Manhattan. The entire construction project spanned four years and was completed in September 2004; work on the Green Roof began in earnest shortly thereafter. Calhoun is the first institution in New York City to design an eco-friendly green roof that offers multiple environmental benefits while providing programmable space for outdoor science and environmental studies. Towards that end, the project received a $50,000 matching grant from the E.E. Ford Foundation, which supports innovative educational programs pioneered by independent secondary schools.

?The Green Roof Learning Center will greatly enhance the students? studies in all the scientific disciplines,? notes Steve Nelson, Calhoun?s Head of School. Chemistry curriculum will be enriched by the study of aquatic environments, and students will engage in hands-on experiments in plant biology. Physics students may investigate solar access as an energy alternative to fossil fuels. And we?re hoping to join a program underway at New York University to detect cosmic rays.? Mr. Nelson also notes that students will be planting and tending an herb garden, to support the school?s lunch program, which emphasizes health and nutrition.Calhoun?s faculty is collaborating on developing curriculum with a number of organizations with whom the school has relationships, including Rockefeller University, the Black Rock Forest Consortium, and the Earth Pledge Foundation.

“Calhoun?s is the first school project in which we?ve been involved,? notes Leslie Hoffman, executive director of the Earth Pledge Foundation, a leader in Green Roof design and education. ?Its effort fits into our overall effort to afford communities the benefits of Green Roofs.?

Green roof type: Semi-intensive (grass with planting beds); Total Size of ?green roof? (including paver area, sedum area and grass area): +/- 2,500 sf; The ?Turf System? ? ?Grass? roof area = 1200 sf was a hybrid grass system by the Motz Group; The 6? System-Sedum roof area 200 sf; Rubber pavers surround the grass; 35 Planter Boxes; Roof Accessibility: Accessible, ADA; (2) ramped walkways have been positioned running North/South along each side of the Turf System. Green Roof System is designed around the 50 pounds per square foot (psf) load requirement, a 10-inch deep green roof, with 5 inches of lightweight granular drainage media and 5 inches of light-weight. The drainage media is 100% mineral and the growth media is greater than 92% organic. This is to provide a durable and structurally stable substrate for the turf.

Green Roof System: Roofscapes; Roof Membrane type: Fluid applied modified bituminous membrane; Insulation: rigid insulation and isocyanurate board; Growing medium depth (inches): 10 Inches for grass; Plant selection: Assorted Grasses, Sedum Album, Sedum Spurium alba Whiteform, Sedum Spurium Fuldagluu, Sedum Cauticolar, Lidakense, Sedum Sexangulare, Allium Schoenprasm, Petrorhagia Saxifraga; Planting method: Grown in place; Drains: 4 roof drains in grass area; Irrigation System: Sub Irrigation; Accessories: Inset planting beds with drip irrigation.