Tropical plants have claimed their spot in improving indoor air quality; trees, shrubs and flowers enhance outdoor landscapes; and now green roofs are stepping up as environmentally friendly ways to cut energy bills, decrease runoff, and filter rainwater.
While common in Europe, we increasingly see and hear of buildings with green roofs, even in Fort Wayne. The Peggy F. Murphy Community Grief Center has an ‘extensive’ system, planted with hardy, drought resistant perennials, mostly succulents. After the first year, it requires virtually no watering or special care, save for an annual trim and light fertilization.
At the Ash Skyline Plaza, Indiana’s largest rooftop green space includes trees, shrubs, and walkways and is an ‘intensive’ style roof garden, requiring some watering, fertilizing and mowing, but still providing the same environmental benefits.
Both styles absorb pollutants, soak up rainwater, and keep the rooftop 8 – 20 degrees cooler in summer and warmer in the winter. These numbers translate into reduced costs, fewer fossil fuels wasted, and a healthier environment. Additionally, the life of the roof membrane can be doubled or tripled.
The American Society of Landscape Architects recently reported that their green roof project reduced wintertime building energy use by 10% from before the green roof. In its first year, the roof kept 27,500 gallons of storm water runoff out of the Washington, DC sewer system, and for rain events less than one inch, the roof typically retained 100% of the rainwater that fell. The green roof also removed high levels of pollutants and all nitrogen from the water that did run off. In Fort Wayne, numbers like these could reduce stormwater runoff that carries pollutants into storm sewers and our rivers.
The earliest green roofs may have been sod houses, so the concept is not new. Systems vary, but the elements are similar. First and foremost, the roof must be capable of carrying the load. Various layers that protect the roof, provide drainage, and hold the often soilless, engineered growing medium are used, along with drought resistant perennials or other plants. Multiple companies specialize in green roof systems and recently kits have become available for the do-it-yourselfer.
Of their green roof, Grief Center Chief Operating Officer, Laura Ankenbruck, says, "Our initial interest was to offer a place of comfort and peace for our clients and any adult in the community who has experienced the loss of a loved one. The garden has also helped us grow as environmental stewards."
by Greta M. Ivanovic