How did their journey begin? In 2014, they found a 107-year old Victorian home on a small city lot in Minneapolis. Serendipitously, Stewart had stopped by a Home and Garden Show, where he heard about the concept of a “net-zero energy” home. Having been intrigued by renewable energy since the energy crisis in 1973, he told me, “When I learned about Net Zero Energy homes, a light bulb went on.” Could they remodel an existing home such that it would not contribute to climate change? The next year of design and two years of construction proved that they could. 

Unique Features of the Home

Typical to most net-zero energy homes, this old Victorian was retrofitted with all LED lights, triple pane windows, and efficient, ENERGY STAR appliances. No gas appliances are in the house, eliminating the need for combustion venting and keeping the indoor air quality healthier (the code-required carbon monoxide detectors will never be triggered). What is not typical is that this home was a remodel—so several innovative ideas needed to be incorporated. Below, we share a few highlights, excerpted and slightly modified from Stewart’s “Innovations” Flyer he wrote himself to share his knowledge.

4.    Making a roof fit for solar panels. 

The original 1907 house had a “balloon” frame constructed of slender 2″x4″s—not suitable for solar photovoltaics (PV). The Hermans added a new roof of plywood I-beams on top of the old roof. The space between the I-beams was filled with 10 inches of foam insulation; combined with the 6 inches of fiberglass batting under the old roof, they were able to insulate the roof to R-80. The roof supports 42 solar collectors—weighing one ton in all. Supporting all this new construction is a massive laminated ridge beam, which workers installed by hand. They added another 12 solar collectors on the detached garage, resulting in a 17-kilowatt solar photovoltaic array that produces more electricity than the house consumes (hence, “Net Zero”).

5.    Getting hot water fast.

One lament of people who live in old homes is that they must run the faucet a long time to get truly hot water from their centrally located water heaters. A small pump was installed to recirculate a loop of hot water, in insulated (R-4) pipes, so that hot water is never more than a five-second wait in the bathroom faucets.

Being Part of the Solution

Looking at our homes as part of the solution to our planet’s issues is becoming a trend because, with newer technologies, we can do so much more with our homes. But what is so unique and important about this home is that it is a renovation of an existing house. As the building community is called upon to address climate change, new buildings can more easily be built to being at least net-zero ready. But the existing building stock—to the tune of over 70 million single-family owner-occupied homes in the United States—presents much more of a challenge.  Since most buildings are existing buildings, and they tend to last a long time, renovations are a necessity. For the Hermans, the overall results are quite satisfying. They estimate they offset carbon at a rate of 12 tons per year. Stewart wrote, “We have the daily, delicious experience of feeling that we are part of the solution rather than part of the problem.”