When Dennis Alex and his wife Tina decided to build their family dream house, they set out to create an energy-efficient home for their future. Says Dennis, “Once we decided to build, we wanted a home for tomorrow’s standards, built to 2030 or 2040 standards, not the code minimum. Otherwise, your home is old as soon as it’s built.” Their new home meets net zero standards, with solar panels that address 100% of their electricity usage, geothermal heating and cooling, and an insulated foundation.
But to get there took research, analysis and planning. The first challenge was finding a builder. Says Dennis, “A lot of people claim to build green houses but what they deliver is minimal.” Realizing that his builder didn’t have the net zero experience he’d hoped for, Alex turned to the National Green Building Standard (NGBS) scoring to guide the entire building process.
Another guiding principle was to invest where it matters in the long run. Says Dennis, “Most houses are sold based on finishes like countertops, but those are eventually replaced. We decided to invest in the bones of the house, the things that are more expensive to add later, like foundation insulation.”
In the Lewiston, New York, area where the Alexes planned to build, many homes rely on big propane tanks for heating during the cold northern winters near Lake Ontario. Although natural gas was available in their neighborhood, the Alexes decided on a geothermal system for heating, cooling, and hot water, a choice that added about $30,000 to the overall cost. But between federal tax breaks and state incentives, the cost was reduced by $20,000, so the incremental cost was $10,000, and when Dennis crunched the numbers, he saw that the ROI would take just six years.
The geothermal system (a Waterfurnace 7) exchanges heat at almost 500% efficiency, compared to the most efficient natural gas furnace at 98%. Since geothermal systems last about twice as long as standard systems and the pipes drilled into the lawn carry an 80-year warranty, Dennis knew that it was a smart investment in their home’s future. When the HVAC system was installed, all the vents were carefully sealed to stop air leaks and the NGBS scoring helped to guide best installation practices that keep the system running efficiently. Says Dennis, “The house is insanely comfortable, a huge difference from our old house. The air handler is a variable speed pump so it’s not a hot then cold cycle, just always warm.”
The choice of an insulated foundation was a hard decision, too, because it’s another very expensive investment that can’t be changed later. He chose foundations made of dense, high-pressure concrete, that’s poured and cured in the factory, using strict quality control. The precast concrete foundation walls are so dense they resist moisture penetration, and the insulation is bonded to the wall, reducing energy loss. The pre-studded walls allow added insulation and basement finishes. The entire foundation was trucked on site, put into place and waterproofed.
The house walls were continuously insulated with Zipwall sheeting to control air leakage and achieve an R6 rating. While triple insulated windows offer the highest performance, they’re very expensive, so the couple chose double-paned windows to stay within budget, having decided on the tradeoff of investing in the geothermal system. All the lighting uses LEDs and tier-one appliances minimize energy use.
To address electricity costs, the couple decided to add a 14.4 kW solar array that essentially eliminated their utility bills. In the winter, the solar panels produce 20-40 kW daily, which jumps to 60-80 kilowatts daily in the summer. Dennis expects that the summer production will give them enough utility rebates to cover their electricity bills in the winter. In New York State, utilities use net metering, which means the home’s meter turns backward when they have excess solar production, giving them an annual credit on their bill.
Once the solar system was hooked up, Dennis used the Sense app to see the solar production and energy usage in real-time. He says: “It was eye opening knowing how much we were using. In retrospect, if we had installed Sense earlier, I would have used it to size our solar system more accurately, but as our family grows, it may turn out to be perfectly sized.”
In Sense, he sees how little energy they need to use on a day-to-day basis and can track all their data. Their goal is to keep energy usage under control so their solar power can offset it.
He likes getting notifications when the home’s energy usage peaks, which typically coincides with a visit from family.
And when they installed a mini gym in their garage and brought in a space heater in the winter, the Sense monitor quickly recognized it so Dennis was able to estimate the yearly cost.
With a little one on the way, Dennis and Tina are looking forward to family life in their comfortable, net zero home. Along with no utility costs, their home’s carbon emissions are minimal–a contribution to the planet’s future.
Thank you, Dennis and Tina, for sharing your net zero home story with Sense!