Air sealing is a priority for Sage Builders. For the carriage house project, it used a blower door to find leaks and sealed them before the home was boarded and plastered. “We also like to use at least 1-inch polyisocyanurate rigid insulation, seams taped, on the exterior side of the exterior frame to act as both an air barrier and continuous thermal break across the framing,” says company principal Jonathan Kantar.
Tom Lingner, The Able Lense, courtesy Sage Builders Air sealing is a priority for Sage Builders. For the carriage house project, it used a blower door to find leaks and sealed them before the home was boarded and plastered. “We also like to use at least 1-inch polyisocyanurate rigid insulation, seams taped, on the exterior side of the exterior frame to act as both an air barrier and continuous thermal break across the framing,” says company principal Jonathan Kantar.

Sage Builders, a design/build company in Newton, Mass., encourages homeowners to build green but must weigh its viewpoint with the client’s needs and budget. As an example, take the 1,200-square-foot dilapidated carriage house it recently converted to an accessory apartment.

“While energy efficiency wasn’t a focus of these owners, we introduced it in a very sensible way, thickening the walls with low-density foam insulation plus closed-cell urethane insulation for certain spots,” says principal Jonathan Kantar, who formed Sage Builders with Scott Mario, another veteran remodeler, in October 2000. “We also used high-efficiency ductless heat pumps for heating and cooling, a propane-powered tankless water heater, and a direct-vented propane fireplace that is a heating source as well as an amenity,” Kantar says.

The project was Energy Star certified and earned a HERS (Home Energy Rating System) rating of 70, meaning that it’s 30% more efficient than a standard building. The air-tight continuous thermal envelope system substantially reduces peak heating and cooling loads.

“We try to make each project as energy efficient as possible, but it’s a compromise between what the clients are focused on and what I’m trying to accomplish from an energy standpoint,” Kantar says. “The pull between a home theater system and extra insulation is always a battle.”

It’s a Stretch

But a recent code development might tip the scales toward more green projects. Newton was the first city in the Commonwealth to adopt the Stretch Energy Code, an amendment to the Massachusetts building code that’s designed to be about 20% more energy efficient than the base code in effect elsewhere in the state. Under stretch-code guidelines, renovations over 2,000 square feet will need to earn a HERS rating of 80; those under 2,000 square feet will have to hit 85.

Kantar worked with a group of local citizens and community leaders to push Newton to the forefront of performance standards. He is also a member of Gov. Deval Patrick’s Zero Net Energy Buildings Advisory Council (see sidebar). “The same kind of issues we face when we try to convince a client to use a more energy-efficient light bulb ... we face when we discuss policy,” he says. “We’re trying to develop a path to some rather rigorous goals.”

—Kathleen Stanley is a freelance writer in Washington, D.C.