UNIVERSITY PARK, Pa. -- With the installation of three more green roofs on Penn State buildings, the university is reinforcing its position as an ecological leader among institutions worldwide.

Last year, green roofs were installed on the new Forest Resources Building (4,700 square feet) and on the top of a horticultural facility known as "The Root Cellar" (4,500 square feet) not far from Eisenhower Parking Garage. Over the next couple of years, green roofs will be installed on three buildings under construction -- the Dickinson School of Law at University Park (10,360 square feet), the Dickinson Law School in Carlisle (11,687 square feet) and the new health center on the University Park campus (12,500 square feet on two separate roofs).

"That will give us close to an acre of green roof space here at Penn State," says Robert Berghage, director of the Center for Green Roof Research in the university's College of Agricultural Sciences. "When they are all done, we will have one of the highest concentrations -- and perhaps the highest concentration -- of green roofs on any campus in North America.

"The notable thing is that we are applying our own research," Berghage added. "Penn State is practicing what we preach. If we believe in green roof technology and benefits enough to invest in them and put them on our new buildings, then obviously we have full faith in them."

Each spring semester, Berghage teaches a class called Ecological Roof and Living Wall Technology in which students get to work on the green roofs and monitor the associated changes in water runoff and temperature. "The living wall aspect is new this year," Berghage explains. "Basically, living walls are sort of green roofs, but vertical. They are mostly built indoors. The growing medium is held by mesh or containers. Living walls have water trickling behind them.

"Our class project will be to put up a green wall in a greenhouse on campus."

Around the world, green roofs are receiving a lot of attention. In addition to the stormwater management and thermal benefits they offer, according to Berghage, one of the hot topics for green roofs is that they provide habitat for ground-nesting birds. "And some people are even investigating growing food on roofs," he says. "That is interesting, but it probably doesn't have large-scale application for commercial production."

Penn State's green roofs have low-growing perennial plants such as sedums and grasses that spread and don't require much maintenance. "They survive the winters -- we may lose a few plants the way you do in any landscaping, but they are spreading plants and they fill in the gaps," Berghage says. "On some of our green roofs, students plant and maintain them; on others it's a classroom situation where they help to monitor runoff and temperatures and do vegetative survey work.

"Penn State is definitely out in front on green roofs, and the more of these things that we build, the further out in front we get," he adds. "We have made a commitment to green certification of our buildings, and that contributes to an attractive environment and a reduction of the buildings' ecological footprints."

Because they offer protection from temperature extremes and ultraviolet radiation, green roofs actually last at least twice as long as conventional roofs, which typically are expected to endure 17 to 20 years, Berghage notes. "A bunch of things happen with a green roof," he says. "You provide attractive surroundings and habitat for birds and insects, and reduce stormwater runoff and air-conditioning demand. No wonder they are starting to attract so much attention."

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EDITORS: Contact Robert Berghage at 814-863-2190 or by e-mail at rdb4@psu.edu.

Writer/editor Jeff Mulhollem: 814-863-2719 jjm29@psu.edu