John and Mindy Miner achieved LEED for Homes Gold Certification over a decade ago with their home in Rockford, Michigan, building above even today’s energy code. Yet they were still determined to go further by going all-electric: buying an electric car, adding solar panels, and recently achieving Zero Carbon Certification with the GreenHome Institute.
LEED certification looks at something called the five pillars of green building: energy, health, materials, water, and place. The home was built in 2009 and certified LEED Gold largely because of its geothermal heating and cooling. The geothermal units are about 400% efficient; no fossil fuels are used for heating, there is a desuperheater for hot water when the geothermal unit is running, and the HVAC system has two zones and programmable thermostats.
Back when the HVAC system was installed, the Miners got at 30% tax credit for geothermal, available to homeowners today via the Inflation Reduction Act tax credits.
Adding to the efficiency, the home was built to be extremely well-insulated and well-sealed. All the walls have spray foam insulation. The foundation has insulated concrete forms, which provides Styrofoam insulation inside and outside the concrete walls. The clerestory windows upstairs create passive solar heating — they let the sun shine in during winter but block it in the summer.
Although the home is extremely well sealed and insulated, there’s plenty of fresh air intake due to its energy recovery ventilator.
Of course, the home has efficiency features like Energy Star appliances, fluorescent or LED lighting, low-volume flush toilets and showerheads, and low-e, gas-filled windows throughout. The Miners had their builder use zero- or low-emission materials, and half the home’s exterior is made of corrugated galvanized steel, which was made out of recycled steel and is recyclable itself so whenever this house is dismantled, that can be reused.
The Miners are proof that even when achieving high-level green building standards, more can be
done to the house to improve sustainability. Their goal is now to have a zero carbon home.
Before their recent addition of solar, the home was using about 9,500 kwh/year. Now their 8.7 kW solar photovoltaic array provides almost all of that, throughout the year.
When they bought an electric car — the Nissan Leaf — instead of adding another row of solar panels, they chose to purchase 8 blocks of renewable energy credits from the Consumers Energy Solar Garden program. Each month they get a fee for using those blocks, but also a credit for how much they produce. Back in August 2020, their electric bill was actually minus $24.
All their energy comes from the sun, and they don’t sacrifice comfort. The Miners’ home was featured in the GreenHome Institute’s 2022 solar decathlon program, demonstrating that geothermal and solar do work to heat and cool a home in climates like Michigan with hot, muggy summers and freezing cold winters.
The home has a HERS index rating of 53, which is ahead of today’s energy codes. However, that score is from before they added solar, AND got rid of the home’s natural gas range and gas fireplace — so the home is now completely gas-free. Its updated score would be even better.
In addition to energy efficiency, another part of LEED is having a healthy home. The Miners’ house is zero-step, so they can age in place, and has lots of natural light. They planted a no-mow type of grass, and in the back yard, which backs up to a creek, they’ve planted almost all native plants to help with bioremediation, keep the water clean, provide habitat for birds and pollinators, as well as cut down on mowing. It also got them a LEED innovation point.
The home is located within walking distance to downtown Rockford, so the Miners can walk or bike to the restaurants, breweries, farmers market, and parks using no energy at all.
