Ball State University is greening its campus from the top on down with the installation of its first eco-friendly roof.About 7,000 square feet of a modular, maintenance-free plant system now covers the top of the two-story North District Energy Station, next to the Duck Pond on McKinley Avenue. Special Section: Going Green The green roof features pallets are made of 60 percent recycled plastic and are filled with low-growing vegetation such as sedum, grasses and other hearty, drought-resistant plants installed in 4 or 5 inches of soil.The plant growth will help insulate the building and reduce the amount of rainwater that flows into the local storm sewer system."This new green roof fits naturally into the university's long-standing commitment to the environment," said James Lowe, Ball State's director of engineering, construction and operations. "It sets the standard for the campus, since it will reduce energy needs for the new building as well as extend the life of the roof by eliminating exposure to ultraviolet light, which degrades roofing materials."The energy station is one of two facilities that will pump heated and chilled water through the much-touted closed loop geothermal energy system, which will be the largest in the nation.When the first phase of the geothermal project is finished this fall, the university will close two coal-fired boilers, saving more than $1 million in operating costs annually.Construction of a second energy station will begin in the fall.Lowe said he hopes the new green roof will lead to similar installations across campus."The Teachers College Building is going to get a hard look, even though it is 10 stories tall. Like the rest of the current buildings, we'll have to study whether it can support the system or has to be retrofitted to handle the additional weight," he said. "In future new buildings, we'll look at incorporating green roofs into our strategic construction plan."