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When the term “green” is applied to buildings, it typically refers to features that reduce energy consumption—effective insulation, efficient heating and cooling systems, electricity-saving lighting setups. And the University of Illinois College of Business’s new instructional facility nearing completion at the corner of Sixth and Gregory in Champaign has all of these things. In fact, the Business Instructional Facility will even generate some of its own electricity with solar panels, and it is set to earn one of the highest certification levels recognized by the U.S. Green Building Council.
But the Business Instructional Facility also incorporates a “green” feature that is literally green, its roof. (Or parts of its roof, anyway.)
One 1200-square foot section on the 4th floor of the building and one smaller section over the auditorium will feature this innovation, which is gaining momentum worldwide as an alternative to conventional flat roofing. Unlike a conventional flat roof, which is designed to move water off the top of a building as quickly as possible, a green roof features a layer of substrate that detains water, and in which low-maintenance plants are grown. Beyond discharging less water than a conventional roof, green roofs are said to discharge cleaner water, thanks to the filtering effect of the substrate and the fact that runoff doesn’t pick up additional pollutants from the roof itself.
A green roof also benefits the immediate environment by remaining cool in warm weather, rather than storing and radiating heat the way a conventional roof does. At the same time, it also insulates the top of the building as or more effectively than a conventional roof.
The green roof on the U of I’s Business Instructional Facility will differ from other green roofs around the country in an important way. Faculty and students from the Department of Civil and Environmental Engineering will be studying it to quantify how well it performs compared to an adjacent conventional roof.
With support from the University of Illinois Environmental Council and the College of Engineering, professors Arthur Schmidt and Charles Werth and a team of students are currently installing monitoring equipment on both roofs.
[Photo: Professor of Civil and Environmental Engineering Arthur Schmidt and students attach the solar panel that will power their monitoring equipment on top of the Business Instructional Facility's green roof.] They will measure how much precipitation falls on each roof, how much of that precipitation runs off into the storm drain system, and how much water is stored in the soil of the green roof. Sensors in that soil will allow the researchers to track how moisture migrates across the green roof and how quickly it returns to the atmosphere. Schmidt and Werth and their team will also compare the quality of the water that drains from both the green roof and the conventional roof by means of automated samplers that will test for pollutants. In addition, researchers will assess how the insulating capacity of the green roof compares to the insulating capacity of the conventional roof by monitoring air temperatures above and below them.
The data gathered in the process of this research will be used as material for study in current civil engineering classes, where students are learning about sustainable building and water-management practices. The knowledge that comes from this research also will help architects and engineers working on future projects--on campus, where all large new construction projects must meet green building standards, and in the world at large--know more precisely the benefits a green roof can provide.
