Parkstone by Legend Homes

Parkstone achieved a HERS rating with and without solar of -36 and 36 respectively. Per this home’s HERS rating, it will save about $2,442 and 1.7 tons of carbon per year. This is great, but an even greater impact is made by combining solar production with an EV (or in this case, two). With gas prices hovering around $5/gal, charging the homeowner’s two EV’s saves a combined $4,800 in gasoline compared with their old Subaru Outbacks, as well as 12 tons of carbon per year. That is over $600 per month in savings. Not to mention, a net zero home means no electric bills, which helps with stabilizing monthly expenditure long-term. Moreover, since this home is not just net zero, but net positive energy, it is helping power other homes in the community with clean energy, reducing their carbon footprints too.

Without accounting for the solar, the home’s energy use is already about a third of the HERS reference home. Reducing the overall amount of electricity needed to run a home prior to adding solar, is a crucial step to sustainability and reducing the upfront cost of a solar array. Methods to do this were designing the home to have a south orientation with living rooms and kitchens on the south side, and bedrooms/bathrooms on the north side. This allows for the spaces to be lit naturally instead of relying on electricity. The windows are all shaded during peak summer hours by extended roof overhangs and porches or decks but allow sunlight during the winter, passively heating and cooling the home. Parkstone has a Chiltrix CX-65 air-to-water heatpump which is highly efficient and also heats the domestic hot water, furthering the home’s energy efficiency. Of course, building a highly insulated and air-tight envelope also helps reduce thermal bridging and increases energy efficiency. The envelope is made up of SIPs walls and roof, triple pane windows, an ICF foundation, and aerobarrier air sealed to an ACH of 0.49.

Additional benefits to going all electric are the health benefits. The home uses an induction range and electric heatpump which are not only more efficient but also reduce the VOC’s emitted compared to a gas range and gas boiler. Since solar is dependable, combining it with battery storage means you will still have heating and cooling in extreme weather events, which are becoming more frequent.

Since Parkstone achieved such a high level of energy efficiency and the solar array installed was oversized, it will be able to power two EVs, the entire home for a family of 5, a hot tub, and an electric sauna. These luxury items are not required, but this home has proven that you can still have an exceptional quality of living with a net zero energy home, all while reducing your carbon footprint!