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Green Roofs

Mitigating Runoff with Green Roofs at SIUE

Sustainability and living green are important at SIUE. As part of our value of citizenship, we support projects that promote social, civic and political responsibility, and environmental stewardship. We engage in partnerships and foster a climate of collaboration and cooperation.

One of these important partnerships is with Ittner, a St. Louis-based architectural firm. The firm recently completed a green roof project on the balcony of SIUE's Rendleman Hall, which is now being used by the building's employees as a daily retreat for breaks and lunch. This modular block system, like the one that rests o n SIUE's Student Success Center roof, will be tested by SIUE's biological sciences and civil engineering departments for green benefits.

Susan Morgan, professor of civil engineering and chair of that department at SIUE, works closely with students to study green roofs and the quantity and quality of storm water runoff associated with them. She has said their use has proven to show "a significant reduction in the amount of runoff from green roofs compared to traditional roofs."

What is Green Roof Technology?

Growing in popularity in the U.S. because of their many environmental advantages, according to the 2008 School of Engineering Dean's Report, SIUE engineers and scientists are evaluating the environmental benefits of green roof technology and the performance of various green roof materials and techniques. The research, which is part of the University's Green Roof Environmental Evaluation Network (GREEN), is taking place on top of the School of Engineering Building, as well as at a ground-level field site. Research conducted by SIUE students and faculty has the potential to influence green technology and future environmental trends.

G.R.E.E.N. is a collaborative initiative lead by the School of Engineering and the Department of Environmental Sciences. The effort involves local St. Louis companies Green Roof Blocks and Jost Greenhouses and other environmental industry leaders and universities. Susan Morgan, professor of civil engineering and chair of that department, works closely with students to study the quantity and quality of the storm water runoff. "While there is the potential for green roofs to add pollutants from the growth media and fertilizer, our data so far shows little contamination," she said. "There is, however, a significant reduction in the amount of runoff from green roofs compared to traditional roofs."

Serdar Celik, SIUE assistant professor of mechanical engineering, studies the thermal benefits of having a green roof. "The green roof acts as insulation," he said. "By having a green roof, the plants promote less building heat gain in summer and less building heat loss in winter." Celik is quantifying the R-values, or thermal resistance, of different growth media-vegetation-fertilizer combinations. According to Bill Retzlaff, associate professor of biological sciences and chair of that department, a green roof on the SIUE Engineering Building lowers the roof temperature in the summertime as much as 70 degrees. "The cost savings from green roofs can be significant," Retzlaff said. "The city of Toronto, Canada, has estimated that they could reduce annual heating and cooling costs by $1 billion if six percent of the rooftops were green roofs."