NMU professor, husband build energy-efficient home
Net-zero house the goal
MARQUETTE — Sarah Mittlefehldt is one of Northern Michigan University’s most prominent sustainability advocates.
As an associate professor, she teaches students about environmental stewardship. As co-chair of the NMU Sustainability Advisory Council, she promotes initiatives and guiding principles that will help the university fulfill its core values, according to an NMU press release.
Mittlefehldt’s commitment also extends to her personal life. She and her husband, John Gillette, set out to build a net-zero home employing renewable technologies and local materials.
“The idea of a net-zero home is that it produces as much energy as it consumes over a year by being super energy-efficient and employing renewable technologies,” Mittlefehldt said in the release. “Residential and commercial buildings consume about 40 percent of all energy used in the U.S. John and I realized this was something we could do on our own to lessen the impact. Gutting an old house to get it up to the energy performance level we wanted was expensive enough that we decided to build a new house instead. We haven’t quite achieved net zero yet; ideally, the next phase will take us there. But our goal is to reduce energy demand overall and to use renewable fuels.”
The house is located at the end of Albert Street near Lake Superior. It is oriented 180 degrees due south, so the low winter sun shines through the windows and warms the concrete floor. When the sun is positioned high in the summer, it is blocked from heating the inside by an exterior overhang of local white pine timber.
The house also features the following: 14-inch thick walls; dense-packed cellulose insulation that is inert and environmentally friendlier than foam; a wood stove complemented by a hydronic heating system that cycles hot water through tubing beneath the concrete floor; and a tankless, on-demand hot water heater. They plan to install solar roof panels at some point.
Third Coast Builders completed framing for the house. Co-owned by NMU alumnus Mike Kantola, the business specializes in timber construction. Kantola graduated from NMU with a double major in environmental conservation and English, then worked for the National Park Service.
Disillusioned by the “governmental bureaucracy,” he returned to his native Upper Peninsula and started his own business with friend and former Ignorant Mob bandmate Ian Zender. The trailer that used to transport their band gear now holds their construction tools.
“We try to do our part to design smartly when we can, and to think about the origin of the products we’re using and their impact,” Kantola said. “That’s the niche we’re carving out. We’re also eager to work with clients who share that same vision. I was excited to be involved in Sarah and John’s project because it’s a forward-thinking approach that I appreciate.
“The goal wasn’t using cheap materials to get bigger things and more space; it was making their relatively modest 1,500-square foot home as environmentally friendly as possible.”
Mittlefehldt uses her new home as a teaching tool. She engaged a group of students in a scavenger hunt to identify energy-efficient characteristics.
“Although the house isn’t perfect, students were able to see firsthand many green design principles that differ from conventional building,” she said. “We’re going to track data over time on energy usage. According to the Marquette Board of Light and Power, the average customer uses 640-650 kilowatt-hours per month. Our highest so far was 200. And our highest gas bill was $20.”
Mittlefehldt and Gillette began working on the project in May, moved into the home with their young daughter in September and continue with some of the finishing work.