Beyond LEED: Why Colleges & Universities Need Green Roofs

Design Collaborative’s Higher Education studio has completed over 3 acres of green roofs in the past five years alone. Green roofs have grown from a fashion statement to become a key pillar of many institutions’ strategic plans.

To better understand why we have seen this recent widespread adoption of vegetated roofs among higher education clients, we’ll take a deeper dive into our work with the University of Notre Dame—one year after the completion of an 85,000-sf roof atop the Joyce Center. The Joyce Center’s vegetated roof is the campus’ fifth, and the largest green roof among all U.S. colleges and universities. It also represents a key milestone in the University’s commitment to cut its carbon footprint in half by 2030.
A High-Performance Building
The Joyce Center green roof provides the University both local and campus-wide benefits. In addition to providing lasting and significant bottom line impact, the green roof improves air quality, reduces noise transfer, and demonstrates the University’s commitment to creating a sustainable future.
The green roof assembly includes a protective barrier for the roof membrane. This protective barrier extends the life of the Joyce Center membrane by 200%-300%. As Tony Polotto, Director of Construction and Quality Assurance for the University of Notre notes, ““We’ve put a roof system on this building that should last 40 years.” This increased lifespan minimizes the disruptions and downtimes associated with construction and repairs, eliminates waste that would end up in a landfill, and decreases the roof assembly’s life-cycle cost by as much as 60% compared to a standard single-ply membrane roof. The vegetated barrier provides natural insulation for the Joyce Center, helping keep indoor temperatures lower during warm months and higher during cold months. This enhanced insulation has created an immediate impact on the heating and cooling loads for the building.
A High-Performance Campus
Notre Dame’s green roofs have an enormous impact on the campus’ infrastructure. Decreased energy consumption means a decreased demand on the University’s power generation; a key component to eliminating the use of coal completely by 2020. Additionally, the soil in a green roof system acts like a sponge, absorbing excess rainwater and decreasing the amount of rainwater run-off from the roof by up to 90%. What run-off remains will occur hours after peak flows and will be filtered and detoxified by the roof’s vegetation. This delayed run-off decreases demand on existing campus infrastructure and returns cleaner water to the downstream collection facilities. Less demand on campus infrastructure means savings in money, disruption, and waste by eliminating otherwise necessary infrastructure upgrades to meet the increasing demands created by new construction on campus.
In addition to the positive impact on energy use and infrastructure, green roofs can achieve a variety of design goals. Some clients want to make underutilized spaces more functional, for example creating a new outdoor amenity atop a parking garage. Others are maximizing campus square footage by placing athletic fields over parking garages.
Going Green
Whether it’s creating less infrastructure-intensive facilities or activating formerly under-used spaces, the common theme for all clients is the demand for new ways to stand out and operate efficiently in a changing world and evermore competitive environment. Green roofs are an increasingly popular component of college’s and university’s strategic visions because they serve so many important purposes. What was once a fashion statement is now a credible tool in the higher education leader’s approach to differentiation and value-generation.

Nathan Woods, RA
Design Collaborative