To explore how the University of Michigan might achieve carbon neutrality throughout the Ann Arbor, Dearborn and Flint campuses, the President’s Commission on Carbon Neutrality is examining ways to reduce emissions across three broad categories.
The categories include “Scope 1,” from energy generated on campus; “Scope 2,” generated from purchased power; and “Scope 3,” from indirect sources.
Campus buildings represent a critical area of analysis, having accounted for over 98 percent of Scope 1 and 2 emissions on the Ann Arbor campus during fiscal year 2019.
“If we can eliminate this high level of energy consumption in campus buildings through energy efficient and cost-effective retrofitting and new builds, the university’s emissions will be significantly reduced as a whole,” said Nicole Rusk, a graduate student at the Taubman College of Architecture and Urban Planning.
“We can bring U-M’s campus much closer to being carbon neutral through addressing the building sector.”
For the last year, Rusk has been part of a team examining opportunities to enable new and existing U-M buildings to demand less energy, while decreasing emissions and reducing operating costs. In her role with the team, Rusk, a Certified Passive House Consultant, analyzed the efficacy of different building codes and green certification programs, such as Leadership in Energy and Environmental Design and Passive House.
Staffed by undergraduate and graduate students, the team is one of many that assisted the commission, covering distinct topics critical toward U-M’s carbon neutrality push. A separate internal energy consumption policies team assessed university-wide policies that could nudge units toward energy conservation measures.
Though a given building’s energy use often correlates with its total emissions, team members are quick to point out that these variables need differentiating.
“It depends a lot on where that energy is coming from,” said Jen Maigret, associate professor of architecture at the A. Alfred Taubman College of Architecture and Urban Planning and co-faculty lead of the team. “If there are similar buildings, of a similar energy consumption, but one of them is being powered by a fuel mix that includes sources like coal, and the other one is being powered entirely by renewable sources, then their emissions are going to be quite different.”
Necessarily then, Maigret said building standards and the team’s work are linked to other efforts underway on campus. As part of its process, the commission engaged SmithGroup Inc. to assess existing U-M buildings and identify opportunities to reduce their respective energy use intensity.
The commission also hired Integral Group, an external consulting firm, to analyze ways to improve U-M’s energy network and move it away from emissions-intensive sources. At the same time, the team notes a myriad of ways to reduce a building’s potential carbon dioxide emissions.
For a new building, incorporating emissions-reducing systems is often easier.
“A simple thing is to have more internal thermal mass,” said Lars Junghans, associate professor of architecture at the Taubman College of Architecture and Urban Planning and co-faculty lead of the team.
“This involves controlling the temperature in the winter and summer time in such a way that, simply by having internal thermal mass, you can lower energy demand variables for heating and cooling. This is what we call a passive method.”
Existing buildings, however, require a multifaceted approach that considers upfront costs, return on investment, and the complex interplay between passive and active building improvements.
“The concepts in architecture are relatively simple,” Junghans said. “But because we have hundreds of different concepts that the architect and engineer have to work on, finding the right solution — the most technical, economic and feasible solution — is more complex.”
Under a traditional approach, architects weigh different renovation measures one at a time. Maigret and Junghans said, however, different active and passive systems often complement each other leading to added gains in emissions reduction. So Junghans developed software to analyze the nexus of potential renovation measures and choose the optimal solutions.
Shuhaib Nawawi, a recent Master of Engineering graduate, has been crucial to this effort, inputting data from 217 U-M buildings, spanning different categories pertaining to the buildings’ functions and energy performance.
“With buildings like hospitals or laboratories that consume a lot of energy, we cannot simply renovate them, because that might disrupt the operations of the buildings,” he said. “There are always patients in the hospitals, there are researchers who need to be in the labs. We needed to make sure that all of our proposals did not disrupt the university as a whole.”
“There are so many variables to respond to and every building is unique,” said Kay Wright, a recent Taubman graduate and team member. “You need to look at climatic, environmental and physical characteristics and all of these moving materials, which really require high sensitivity to context, place, but also the culture of how the building is used.”
Wright joined the team interested in learning about the integration of passive heating and cooling systems at an institutional level. Over the past several months, she analyzed how comparable universities were implementing their own building standards, with an eye in particular toward water conservation. Having reviewed 37 other universities, Wright notes that U-M has a tremendous opportunity to reduce its gallon-per-person water use.
Going forward, innovative buildings standards can accomplish even more.
“In the scope of a post-COVID world, an energy-efficient building, built well with a good air changer, is just a healthier building with healthier occupants,” Rusk said.
The building standards analysis team also includes Hannah Irish of LSA and McHugh Carroll and Mitch Mead of the Taubman College of Architecture and Urban Planning.
The carbon commission expects to make its draft recommendations available for public comment during the fall and deliver its final report by the end of the calendar year.