A few weeks ago, my wife and I went on a short hike with our college-age son. As the three of us drove to the trailhead in Norwich, Vermont, we passed a construction site. “Looks like a zero-energy house,” I observed. The sign out front read, “Prudent Living Homes.” I decided to get more information on the house and return later to try to talk with the builder.
I called up Prudent Living Homes, and the owner of the company, Paul Biebel, agreed to meet me at the site. When I showed up a few days later, two carpenters, Gary Castellini and Maynard White, were working on exterior details.
The house in Norwich is a custom three-bedroom home measuring 2,500 square feet. The home’s 13-kW photovoltaic (PV) array should produce enough electricity on an annual basis to more than meet the home’s electrical needs.
The foundation consists of perimeter stemwalls surrounding a slab on grade. (The design originally called for a basement; however, once the excavator started digging the foundation hole, a natural spring bubbled up — one that no amount of drainage pipe was likely to defeat. The team decided to switch gears and build on a slab.) Insulated concrete forms (ICFs) from Nudura were used for the stemwalls; additional rigid foam installed on the exterior side of the ICFs increased the R-value of the walls to R-22. A 4-inch-thick horizontal layer XPS (rated at R-20) was installed under the slab. (See Image #2 at the bottom of the page.)
The R-45 double-stud walls are 12 inches thick, and are insulated with dense-packed cellulose. (See Images #3 and #6 at the bottom of the page.) The roof is insulated to R-60.
Paul Biebel, owner of Prudent Living Homes in Windsor, Vermont, has been building homes since 1976. “I’ve…