"We brought the earth up around us," Lefevre said. "It works like a cave."
The solar mass block forms the floor of a solarium which is open to the sky. The solarium - which is separated by walls of glass from the rest of the home - is the only room in the house that has an expanse of uninsulated glass.
In the basement, Lefevre can adjust the pipes to control the water flow. Most of the time, only the pipe that runs under the floors in the open living room and kitchen area is on. It provides enough heat on a chilly fall day to keep the house comfortable.
In the winter, it can get so hot that the family will open vents in a cupola to release warm air. The dome-like structure also affords a 360-degree panorama of the surrounding woodlands.
Solar panels on the roof provide power for hot water. The home, with 52 windows to provide plenty of natural light, uses little electricity, Lefevre said.
"We're not short on any amenities," Lefevre said. "We're already living in the home of the future."
Green homes in Methuen
What: Six to eight new "advance solar technology" homes.
Where: Wingate Avenue subdivision called Pellegrino's Way.
How it works: Passive and active solar-powered features provide all the heating and cooling. A thermal mass of insulated concrete and steel keeps the temperatures constant and the air dry and comfortable.
Cost: About 15 percent more to build than a traditional home.
Projected market price: $440,000 to $480,000.
Construction: To start in late 2008, and takes about a year.
Designed by: Bob Lefevre, formerly of Methuen, now of Kingston N.H.
Developer: Robert Pellegrino of Pellegrino Construction.