Living Roof Aims to Cut Energy Costs

In a few decades, gardens sprouting a rainbow of flowers might cover the roofs of Carnegie Mellon University's buildings, cutting energy costs and minimizing the campus's environmental impact.

The project began four years ago when three undergraduate students received a small grant to study green roofs. After discovering that Hamerschlag Hall needed a new roof, they enlisted the help of CMU faculty and staff. The students got $96,750 from the state Department of Environmental Protection and $25,250 from 3 Rivers Wet Weather, a nonprofit environmental group, to pay the additional cost of planting a garden atop the building. The pair hope that when skeptics see the roof doesn't leak or collapse, green roofs will become common on campus and throughout the city.

Water runoff will be used by the plants and absorbed by the soil. The garden will insulate the building from the summer sun and winter cold, reducing cooling and heating costs. Rainwater runoff  from two large gardens in the center of the roof will be measured against that collected from a neighboring control roof, which is covered only in stones. A small, 3-foot-by-4-foot pond fed by water collected in gutters and logs with insect holes drilled in them will encourage birds and bats to frequent the area, creating an ecological system. http://www.cmu.edu/greenpractices/green_initiatives/lr_hamerschlag.html

For more information on green roof design, contact F. X, Browne, Inc. at info@fxbrowne.com.

Tribune-Review, May 30, 2005