A Freeport project looks for the most cost-effective ways to weatherize existing homes.
by Tux Turkel, staff writer
What would it take to slice consumption by half, or even three-quarters?
That’s a question being asked around the country in the building science field. Researchers say 80 percent of all homes are more than 30 years old and need major energy upgrades.
Some of the answers could come from an abandoned 1875 house that stands a boot’s throw from L.L. Bean. It could become Maine’s first example of what contractors call a “deep energy retrofit.”>/p>
Proponents have a $10,000 federal research grant to finance initial engineering for the Mallett Deep Energy Retrofit. Now they’re trying to find money to do the work.
“We can’t solve the building energy issue with new construction,” said Peter Troast, an energy-efficiency products retailer who’s helping to lead the project. “At some point, we’ll skim the cream to get that 25 percent reduction. Then the real energy savings will have to be done with a deep retrofit.”>/p>
By deep retrofit, Troast means insulating and sealing a home’s walls, foundation and ceiling to levels where very little warm air escapes in winter. That’s easier to do in new construction, but it’s time-consuming and expensive in an old home.
One goal of the Freeport project would be to help standardize methods that seriously tighten the building envelope. Troast and the job’s contractor, Warren Construction Group, plan to do that mainly by sheathing the home’s outside walls with a thick coat of rigid foam insulation.
Another goal is to develop techniques to help lower the cost of a deep energy retrofit, estimated at $30,000 for the project house. That doesn’t make financial sense at today’s energy prices.
That conclusion has been reached elsewhere in the country. A recent project in Tennessee that included solar hot water and electricity – and cut heat use by 65 percent – had a simple payback of 22 years.
But the equation could change, especially in Maine, which is highly dependent on fuel oil for heat.
“There will be a lot more of this work done when we get back to oil costing $4 a gallon,” said Peter Warren, the contractor.
The project house is along a row of historic buildings on Depot Street known as the Mallett houses. They’re named for E.B. Mallett Jr., the 19th-century entrepreneur who pioneered Freeport’s now-defunct shoe factories. He built homes for his mill managers along the street, two of which were renovated by Warren into a community center.
The vacant house is owned by Freeport Community Services and stands next door. It’s in sorry shape. A tarp over the roof keeps out rain. Windows are boarded up. It’s the perfect laboratory for a deep energy retrofit, in Troast’s view.
To tighten the building envelope, Troast and Warren first considered tearing out the plaster walls and creating more insulation space indoors. But that approach would encroach on staircases and not address the dilemma faced by the thousands of homeowners who won’t rip out their interior walls.
That led them outdoors, with plans to cover the house in 4 inches of poly foam, followed by plywood, house wrap and new shingle siding. Combined with cellulose insulation in the existing walls, the technique will create an exterior wall with a very high R-value of 40. (An insulation’s R-value measures its effectiveness.) A similar technique on the roof will bring the R-value to 50.
Broken glazing will be replaced with advanced, triple-glazed windows that attempt to honor the home’s architectural heritage. The stone-foundation cellar will be lined with foam insulation, and the entire house will be caulked and sealed to limit air and moisture movement.
The home would be heated by a high-efficiency propane furnace. To preserve indoor air quality, a special ventilation unit that recovers waste heat would be installed. Solar panels would provide some electricity.
Each retrofit measure has been examined by Building Science Corp., a consulting and architecture firm. The company has estimated the cost of each technique and the percentage of energy savings, compared with a benchmark home from the 1990s.
The Somerville, Mass., company led a similar project last year with a large older home in Concord, Mass. The goal was to cut energy use by 50 percent. The retrofit, which used many of the techniques being proposed in Freeport, cut natural gas costs from $2,400 to $858 a year, or about 64 percent.
Troast and Warren are still making decisions that will influence the eventual cost of the upgrades in Freeport, but they figure the $30,000 investment would take six years to pay for itself at current energy prices.
That’s still too much for the state’s pending weatherization program, which is being organized through Efficiency Maine, a program of the Maine Public Utilities Commission. The state wants to spread out the first blast of federal money to reach 4,000 homes. Efficiency Maine figures it can cut energy use in these homes by 30 percent or so, spending $4,000 to $10,000 per home.
“We have to look at how to reach a lot of homes and get them to a 25 to 30 percent level, which is still vastly better than where they are now,” said Evelyn deFrees, a PUC spokeswoman.
But the Mallet Deep Energy Retrofit proposal is important, deFrees said, because it could serve as a demonstration of what will be possible in the future.
That’s the thinking of Affordable Comfort Inc., a Waynesburg, Pa., nonprofit that is working on home building performance issues. The group is trying to organize the Thousand Home Challenge, which aims to launch 1,000 projects in the United States and Canada that will cut energy use by 75 percent to 90 percent.
Affordable Comfort is aware of the Mallet proposal and wants to include it. One variable: Troast may turn the house into office space for Energy Circle, the Freeport company for which he is chief executive officer.
“But the methods he’s using would be in line with what we’re trying to demonstrate,” said Linda Wigington, the group’s special projects director.
Just getting the Thousand Home Challenge under way will be a challenge. Affordable Comfort must sell the benefits of added comfort and resale value, for instance.
“We don’t have enough evidence yet to demonstrate the value,” Wigington said. “It’s not going to pencil out, if you just look at energy savings.”>/p>
In Freeport, Troast and Warren will need to raise nearly $300,000 to do the entire project. That would fund a total rehab of the house, in addition to energy-saving measures.
They’re looking at federal grants and other sources. If they’re successful, they plan to keep sections of the walls, roof and foundation open, so visitors can inspect the building techniques.
“This is a perfect example of the kind of Maine architecture we need to learn how to deal with, from an energy standpoint,” Troast said.