A group of students recently took a trip to the top of the PECO skyscraper, where they learned about advancing sustainability in an urban area.
Students in a fundamentals of horticulture class on Main Campus recently took a tour of the PECO Building’s green roof at 23rd and Market streets to learn about sustainable design and incorporating plants into architecture.
After an introduction around a model in the lobby that demonstrated layers that support the rooftop plants, students took the elevator up to the eighth floor and walked onto the roof. Like a sky-high field of turf, the plants stretched to the edges of the building. Skyscrapers from Center City climbed from behind the rosy tinge of fall color on the plants’ leaves.
Based in Philadelphia, PECO is an electric and natural gas utility subsidiary of Exelon Corporation. This past September, after a half a year of work, the company unveiled this 45,000-square-foot green roof on the top of its headquarters. The green roof is part of PECO’s commitment to reduce its energy use through a comprehensive environmental strategy, and the green roof is now the largest ever installed on an existing building in an urban area in Pennsylvania.
The green roof will help reduce storm water runoff by absorbing 60 to 70 percent of the approximate 1.5 million gallons of annual rainwater that falls on the PECO building and will cut down on temperature regulating costs by reducing the summertime peak roof temperature by 60 to 80 degrees. The vegetation also will absorb air pollution and particulates.
The roof surface consists of a mat of different plants ranging from 4 to 8 inches in thickness. Professor Julie Regnier squatted on the spongy bed of plants and described the importance of using succulent vegetation in this type of architectural design because it holds a great deal of water and is able to withstand harsh conditions.
“A roof top is very much like a large, windy mesa in the desert Southwest,” she said to the class. “The sun is relentless, the wind is scouring. Plus, succulents don’t shed a great deal of organic matter [that] adds up in weight quickly and would be difficult for the building structure to withstand.”
Students kneeled down to sink their fingers into the dense carpet of living vegetation.
“I didn’t think that it would decrease the heat level of the top floors, but it makes sense with all the heat and light the roof absorbs,” said Christopher Babcock, a freshman journalism major.
“I hope more buildings take this into consideration because it’s a novel idea and a rewarding investment.”
Dr. Julie Regnier explained that in a class like the fundamentals of horticulture, where the majority of students come from diverse backgrounds, fieldtrips like this demonstrate how horticulture can be integrated into different careers and offer a survey of what possibilities lie in the field of horticulture. Not to mention, students attend class on the roof, while learning about green initiatives in their city’s backyard.
Sierra Gladfelter can be reached at firstname.lastname@example.org.