The Calhoun School celebrated the opening of its new Green Roof Learning Center with a ribbon cutting ceremony on Tuesday, May 3, 2005.

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,” noted 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 added 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.”

Calhoun’s Green Roof was designed by Fox & Fowle Architects, the firm that also designed the school’s recent four-story building expansion. At the unveiling ceremony in May, Bruce Fowle, senior principal of the firm, explained that the Green Roof not only provides an aesthetic and educational element to the school, but it will also provide real environmental benefits: it will reduce storm water runoff by 40 percent (an average of almost 26,000 gallons of water every year); provide insulation to reduce heating and cooling needs; help filter the air by absorbing carbon dioxide and giving off oxygen; and provide a food source for wildlife.

Founded in 1896, the Calhoun School is a coeducational, independent school on Manhattan’s Upper West Side educating 670 children from preschool through 12th grade. The school is housed in two buildings, one on West 81st Street and a second on West 74th Street. As a leader in progressive education, the school prides itself on its innovative, academically challenging curriculum, its commitment to diversity and community, and its dedication to nurturing the whole child—intellectually, creatively and ethically.

Calhoun Green Roof Specifications
Project Team

Architect: Fox & Fowle Architects P.C.

Structural Engineer: Anastos Engineering

Construction Manager: Sciame

Roofing Contractor: Eagle

Landscape Contractor: Town and Garden

Green Roof Consultant: Roofscapes Inc.

Plant Supplier: Town and Gardens

Green Roof System Manufacturer: Carlisle

Roof Membrane Manufacturer: Carlisle

Growing medium Manufacturer: Big River Industries

Growing Medium Distributor: Town and Gardens

Accessory Supplier- Stabilized Grass Roof Supplier: The Motz Group

Green Roof Type

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 Sq. Ft.
The ‘6” System’-Sedum roof area 200 Sq. Ft.
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 Details:

System 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 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: Drip Irrigation
Accessories: Inset planting beds
Maintenance: Weekly mowing, irrigation, occasional weeding and fertilizing.

Warranty — 20 years from Carlisle

For information, contact: Beth Krieger, Calhoun School, Director of Communications;
beth.krieger@calhoun.org
The Calhoun School, 433 West End Avenue, New York, NY 10024, 212-497-6500