Try Superinsulation For a Tight House, Maine Builder Says
Though cost is higher, energy savings swiftly add up
NO one would have jumped at the chance to live at 47 Essex Street in this old mill city in central Maine, despite a nice view of the Penobscot River from that address. The upper story of the old triple-decker located there was gutted by fire last July, and the building was damaged throughout.
In the next couple of months, however, the attractiveness of this piece of real estate will climb as a work crew rips out charred wood, remodels the interior, and - most important to builder Neal Carter - tightly sheaths the whole structure, from the ground to the roof line, in a new 4-1/2- to-6-inch skin of rigid foam insulation sandwiched between wafer board. When it is completed, the Essex Street address will be home to three families, who should have no problem with the cold winds that whistle throug h this part of Maine much of the year.
In the basement, a boiler unit that is a fraction the size of the old one will heat the house, using less than half the amount of fuel oil. The plumber working on the project, who is familiar with Mr. Carter's superinsulating techniques, is willing to guarantee that the upper unit will stay comfortable without heating elements of its own, the builder says.
Carter is one of a small corps of builders around the country who are sold on the benefits of superinsulation. Many are in the northern tier of states, but a few are located in the South and Southwest as well, where cooling costs can be higher than heating costs up north.
Superinsulators install a thickness of insulation, either blown in or rigid, that creates an * value - a measure of how many British thermal units (Btus) of heat go through a square foot of wall area per hour - that is far higher than the value built into ordinary houses. The higher the * value, the lower the heat loss. Carter's standard is R-40 for walls and R-60 for ceilings. A conventional insulated suburban home might have corresponding * values of R-11 and R-19.
Does the extra insulation pay off? Carter is convinced that it does, though he realizes that people tend to shy away from the added initial cost - whether in a "retrofit" like the Bangor triple-decker or in a new building. The concern about the cost of insulating sometimes obscures other savings, he says. "We're often able to build a superinsulated house for close to the same cost as conventional construction, because you can downsize the heating system - maybe a $2,000 unit [will be sufficient] instead of a $5,000 one."
Half the cost of the rigid insulation applied to the Essex Street building is being offset by the savings from a smaller furnace, he says. And for every eight feet of baseboard heating that is not needed, he saves $135.
Carter has kept detailed records of the costs of remodeling and operating the several apartment buildings he owns in the Bangor area. He asserts that the monthly costs of the buildings - mortgage plus heating and utilities - is lower than it would be in conventionally constructed units.
Bill Lemke, executive director of the Energy Efficient Building Association in Wausau, Wis., explains that the kind of retrofitting practiced by Carter migrated down from Canada in the mid-1970s. He says it has yet to catch on as much as it should in the United States. Mr. Lemke contends, though, that superinsulation is not a major addition to the reroofing and re-siding costs buyers of older builders often face anyway - and the payoff is significant. (In addition, Carter will be able to reuse most of th e old siding from his building.)
Lemke also notes that the outer skin of rigid insulation chosen by Carter for his fire-damaged property in Bangor is just one option. Another - usually less expensive - choice, Lemke says, is to suspend a new outer wall made from two-by-fours from the roof and fill it with fiberglass insulation.
A persistent concern about superinsulated houses is that they don't allow air to circulate, thus creating stale, perhaps polluted indoor air. "I always try to uncouple the idea that superinsulation is `too tight,' " Carter says.
He acknowledges that tightness is a must. He regularly employs a heavy plastic "house wrap" inside the insulated outer skin of his retrofits in order to ensure a uniform block to moisture. Any seam or chink in the new skin is filled with sprayed-in foam. He also uses argon-filled multipane windows, with a much higher insulating value than single panes.
The result is a house so tight that the whole structure can be heated from one point because, as Carter explains, "the heat loss is greater from room to room than to the outside."
The need for ventilation is crucial, Carter readily agrees, but he says it can be adequately met through a combination of standard exhaust fans in kitchens and bathrooms plus "high-tech holes" - vents cut through walls that can be operated either manually or automatically. During winter, these vents allow in fresh air, which is directed toward the ceiling so it can warm up before it circulates.
Carter mentions that experimentation also is under way to use the "stack effect," by which air moves vertically through a structure, as a means of controlled ventilation in superinsulated homes. That could eliminate the need for electric fans.
Many of Carter's retrofitted buildings incorporate solar technology along with superinsulation. One multifamily unit, also on the bluffs overlooking the river, has solar panels placed inconspicuously between windows on its mansard roof. The builder says he always tries to counter the perception that solar panels are usually "ugly" afterthoughts on buildings.
His own home in nearby Charleston, Maine, has a wide, treeless view to the east and south. It includes both passive-solar-design and active-solar systems for hot water. Until recently, when new state regulations stopped the local phone company from selling its used batteries, the wind generator rising behind Carter's house supplied much of the household electricity needs for Carter, his wife, and their two small children. Now that he has no way of easily storing the electricity, the propeller is rarely u sed.
Carter has roots in the back-to-the-land movement that brought many young people to rural Maine in the 1970s, when he settled here after graduating from Bates College in Lewiston, Maine, and started his business. He maintains the environmental ideals of that movement, but he also has a firm grip on economic pragmatism, as one might expect from a third-generation home builder. His father and grandfather ran construction firms in Connecticut.
According to Carter, his experience has shown that radical energy-saving steps can benefit homeowners, landlords, and tenants. The builder emphasizes that superinsulating technology also has applications in warmer climates, where energy costs for cooling are steep.
"I want people to start realizing that this stuff [superinsulation] makes economic sense," he says.