Super-Insulated, Energy-Efficient Modular 

The Treats 2,400-square-foot house was built at the Keiser Homes factory in Oxford, Maine. As promised, says Treat, "The house arrived in four boxes on flatbed trucks. It was done all the way to the plaster on the walls. The electric was in, and the plumbing was roughed in."

"We use double stud wall assembly with a three-inch thermal bridge and dense-pack cellulose insulation," explains Meyer. "The windows are triple-pane. The doors are high-performance and insulated. Because the home is modular, it requires a four-inch crawl space or basement that's fully insulated and integrated with the thermal envelope of the house."

The air-tight construction resulted in R-40 walls, an R-60 roof, the slab at R-20, and the foundation walls at R-10. While assembling the home, the construction team sited the house for maximum solar gain - an 8.83 kW system by SunBug Solar powers the all-electric home. The project payback was projected at four to five years, with savings of $82,364 over 30 years, while producing 104% of electricity needs a year.

"We got our payback in a little more than four years," Treat says. She also wrote a blog on the family's energy use. In 2016, she wrote, "The total for our home energy use? $433.74! For a year! That's heating, cooling, hot water, cooking, appliances, even plugging in our Chevy Volt each night. Wow."

The Treats looked at electric options for heating and cooling that would work in conjunction with the home's rooftop solar array. Natalie was set on electric heat pumps, given her work with Northeast Energy Efficiency Partnerships, as the works on market strategies to advance energy efficiency. They decided electric heat pumps would provide more efficiency at less cost than a ground-source heat pump.

Nonetheless, the couple's home was selected as Boston Magazine's Design Home in 2014. "We enjoy making our house available for people to learn from," Treat says, "and have opened up our home for tours with BrightBuilt. With our input, BrightBuilt's process has become much better."

Adds Meyer, "The house continues to serve as a vehicle for promoting the idea of high-performance homes and what that entails. It's also certainly indicative of what BrightBuilt does and how we serve clients." Moreover, "We live in a beautiful, comfortable, net-zero home," says Treat. "We're so pleased."