Earlier this morning Environmental Entrepreneurs (E2), Massachusetts Governor Deval Patrick and representatives from Maclay Architects were gathered in Newton to provide tours of the “house of the future.” The residence, home to E2 Director David Miller, is the first net-zero energy, LEED platinum home within walking distance of Boston’s T. What, exactly, does that mean? Bill Maclay, principal at Maclay Architects, the Waitsfield, Vermont company that designed the house, explained.
A net-zero house or building is a structure that produces as much energy as it consumes. To achieve this architects reduce the amount of energy the home needs and design the building with its own means of generating energy. Over a year, the result is a net-zero energy calculation (this is figured over 12 months because in New England, more solar energy is produced during the summer months than in the winter).
Generally speaking, net-zero buildings feature higher-quality insulation and enhanced mechanical and ventilation systems (to reduce energy needs) and solar panels (to produce energy.)
The Miller home features several categories of material that provide higher levels of insulation than traditional materials, including R5 windows, R40 walls, an R20 basement and an R60 roof, says Maclay. “In an R40 wall, for example, the walls are around 12” thick, versus 6” thick in a traditional home,” he explains, “and that thicker wall may use different insulation than is typically used.” The home also features very energy-efficient appliances (for heating and cooling) and energy-efficient lighting, further reducing the home’s energy needs.
On the flip side, the home uses solar panels to produce both electricity and hot water. The placement of the solar panels is critical, however. “You gain the most solar energy when a home faces due south,” Maclay says. But the challenge with this house, as with any house, is the location of the street. How do you orient a home to both face due south and face the street? “We solved this dilemma by having the garage and part of the house face the street, but the major segment of the house goes off on an angle so it faces due south,” he says. The home also has fewer windows on the north side of the house, and very limited east- or west-facing windows, as the position of the sun doesn’t provide direct sunlight from the north and may produce overheating from the east and west.
In addition to the solar panels, the Miller home features an air source heat pump that “extracts energy from the air. It’s 2 ½ times more efficient than direct electrical use,” Maclay notes. When a home is as tightly sealed at this one, however, it also requires a source of fresh air, so Maclay added an energy recovery ventilation system that brings fresh air into the house and extracts energy from air going out.
The result of all this work? A home that is not only beautiful and highly energy efficient, but also “more comfortable and that has fewer headaches than a traditional home,” says Maclay. “You don’t get frozen pipes, for example, and you can sit comfortably by the windows, as the glass stays warmer. With more fresh air and natural light, it’s a healthier way to live. You actually get a better quality of life with this type of house.”
Living healthier? Reducing reliance on energy derived from fossil fuels? Fewer homeowner headaches? Sounds like a dream house of the future to me.
Barbara Call is director of content for Greenough. She can be reached at firstname.lastname@example.org or follow her on Twitter @BarbaraCall1