The design of green roofs—and all of their stormwater filtering, energy efficiency enabling, heat island mitigating, and habitat providing features—is poised to improve following a two-year research partnership between Portland State University (PSU) and Walmart that will collect in-depth data on the largest green roof installation in Portland.
PSU’s Green Building Research Laboratory will lead the effort to deploy scores of sensors and a weather station on Walmart’s new Hayden Meadows store in North Portland, which will feature 40,000 square feet of vegetative roof installed in three separate sections—each devoted to testing different aspects of green roof design, such as materials and soil depth. The remaining 52,000 square feet of white membrane rooftop will also be monitored by sensors, providing an opportunity to deliver side-by-side comparisons on factors including surface temperature, water flow and building operations. Data collected from the Hayden Meadows roof will be compared to similar data collected on a Walmart green roof in Chicago, providing a comprehensive view of green roof performance in various conditions.
“The data we collect will help the green building industry improve upon the many benefits provided by green roofs—from reducing heat island effects to improving overall building performance,” said David Sailor, director of the PSU Green Building Research Laboratory and professor of mechanical engineering. “This research project will lead to better green roof design for buildings around the world.”
The PSU Green Building Research Laboratory, housed at the Maseeh College of Engineering and Computer Science and funded in part by the Institute for Sustainable Solutions, will lead the two-year research project working with students and community partners. The city of Portland’s Bureau of Environmental Services will measure stormwater runoff; the Cadmus Group, an environmental consulting firm, will monitor the performance of the rooftop air conditioning units; and the Audubon Society of Portland will conduct bird count surveys to contribute to the habitat monitoring portion of the study.
The Walmart Haden Meadows research project builds on PSU’s growing expertise in green roof design and monitoring that has been funded by organizations including the National Science Foundation, the U.S. Environmental Protection Agency and the Oregon Built Environment and Sustainable Technologies Center.