PSU and Walmart Collaborate on Green Roof

Look for Portland State University students climbing on the Walmart roof, the green roof, that is. Under a two-year research partnership between the Oregon school and the retail giant, PSU is building a green roof research site on Walmart’s new North Portland store.

Designing green roofs is not just about slapping huge solar panels on large rooftops. It’s also about using the space to filter storm water, enable energy efficiency, mitigate heat islands and provide habitat. The partnership will enable the collection of in-depth, real-time data on the largest green installation in Portland.

PSU’s Green Building Research Laboratory will deploy scores of sensors and a weather station on Walmart’s new Hayden Meadows store. It 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, thus providing a comprehensive view of green roof performance under various conditions, PSU says.

“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 lab is located at the Maseeh College of Engineering and Computer Science and is funded in part by the Institute for Sustainable Solutions at PSU.

In addition to student involvement, the project has community partners, such as the city of Portland’s Bureau of Environmental Services, which will measure stormwater runoff. The Cadmus Group, an environmental consulting firm, will monitor 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.

PSU’s green roof design and monitoring initiatives also receive funds from the National Science Foundation, the Environmental Protection Agency and the Oregon Built Environment and Sustainable Technologies Center.

With 30,000 undergraduate and graduate students and a motto that says, “Let Knowledge Serve the City,” PSU is serving the green roof cause for all cities.

Image: Roof_Wide_Web from the PSU website