Mendoza’s new roof: It’s alive!

Mendoza’s green roof begins installation. (Photo by Matt Cashore/University of Notre Dame)

Amid the shingles, gutters and concrete on the new roof of the Mendoza College of Business building lives more than half an acre of vegetation. Specifically 31,100 square feet, or 9,075 plant trays, of 11 different varieties of sedum and allium — succulent-like plants that are easy to maintain and tolerate drought.

This latest green roof is part of the University of Notre Dame’s broader mission to contribute to a more sustainable world. Since 2008, all new on-campus construction has been Leadership in Energy and Environmental Design (LEED) certified, which signifies compliance with key sustainability standards from the U.S. Green Building Council.

The Morris Inn became home to Notre Dame’s first green roof in 2009. The Joyce Center later received what was then the largest green roof in Indiana, followed soon after by Notre Dame Stadium. Since those early projects, every new roof constructed on campus is considered to include a green roof, including the Morris Inn (‘09), Joyce Center (‘18), Corbett Family Hall (‘21), O’Neill Hall (‘21), Duncan Student Center (‘21), Alumni Hall Addition (‘23), Eck Hall of Law (‘23), Rockne Memorial (‘24), South Dining Hall (‘25) and now the Mendoza College of Business.

Mendoza College’s Green roof installation. (Photo by Matt Cashore/University of Notre Dame)

As Mendoza was due for a roof replacement, the building’s structural design made it an especially good fit for a green roof. The North Addition construction project also provides an ideal opportunity for one, which is scheduled to be installed in Spring 2026.

“The University is leading the industry in sustainable measures and in reducing our carbon footprint,” said Ron Grisoli, Mendoza’s facilities director. “Green roofs are one of the many things that the University is doing to achieve that. We were really blessed to be selected for this initiative.”

A green roof protects the surface from UV rays, mechanical damage and thermal shock, which is the contracting and expanding of roofs triggered by rapid shifts from hot to cold temperatures. The insulation the roofs provide saves on energy costs. The system absorbs rainwater, helping to divert rain from the storm sewer system. Green roofs are projected to last 40 years, which is nearly twice as long as a normal roof.

Tony Polotto, Notre Dame’s director of construction and quality assurance, has been leading the green roof initiative on campus, teaming up with the College of Engineering to gather cost-savings data. The engineering students are also researching how much rainwater is being diverted from the storm sewers and how a green roof impacts the “heat island effect,” which refers to the reflection of heat back into the atmosphere.

The roofs come with a heavy upfront investment, but require minimal maintenance. They have to be weeded about three times a year to stave off the infiltration of invasive species and they require annual fertilization to promote plant growth and health. The plants themselves are drought-resistant, but to maintain plant health, they will occasionally be irrigated. Given the longevity and benefits of the roofs, Polotto and Grisoli both feel the upfront cost and maintenance are entirely worth it.

Polotto’s favorite attribute of green roofs is their aesthetic appeal. “There’s so much value in what it does to us as humans to look outside and see a nice green roof or surface instead of looking out and seeing something dirty or dry; they truly are amazing transformations.”

Grisoli appreciates how these roofs create natural habitats for birds, insects and other wildlife in urban areas.

Students are at the core of Polotto’s passion for these roofs. “The students are the most important thing to the University. I hope they appreciate it, because at the end of the day, this is really for them, for the betterment of the world and to know we are striving to do the right thing.”