The most effective way to save money on heating and to conserve fuel this winter may be something different than you think. (Hint: not new windows.)
Waterbury Local Energy Action Partnership recently spoke with Brad Cook, owner of Building Performance Services in Waitsfield, to find out what he has learned over 12 years advising homeowners. Cook’s company does energy audits, weatherization, and general repairs to homes and small businesses.
If you would like to learn more, Waterbury LEAP and Efficiency Vermont are co-hosting a free Button Up Weatherization and Home Heating Workshop on Thursday, Nov. 15, from 6 to 7:30 p.m. in the Steele Community Room of the Waterbury Municipal Building. Free pizza, beverages and energy-efficiency raffle prizes will be provided. No RSVP required.
This article is part of an occasional Waterbury LEAP series with local experts about energy-related topics. The interview was edited for length.
Q: What are people looking for when they call you?
A: Some people are motivated by saving money. But, more often, it is comfort: “The house is drafty.” Or “I can’t get the upstairs warm enough.”
Q: Where do you tell them to start?
A: Weatherization, but even before that, priority No. 1 is conservation. If no one is home all day, turn the thermostat down. People sometimes think that is not going to save much energy if you have a well-insulated house. But the amount of heat you lose is directly proportional to the heat difference between the inside and outside of the house. If you lower that difference by 20 percent, then you’ll save 20 percent of your fuel.
Also, when you get home and turn that thermostat up, the boiler and furnace are going to run longer, which is more efficient than short bursts.
The second step is weatherization, which is sealing air leaks and adding insulation. Then install a heat pump. If you don’t weatherize first, then a heat pump or new heating system could be oversized, decreasing its efficiency.
Q: How do you begin weatherization?
A: We do an energy audit, starting with a blower door test (for air leakage), which not only tells us how drafty the house is but also helps us find where those drafts are coming from. Air leakage typically accounts for 30 to 50 percent or more of the heat loss of the house. Doing the blower test is also the start of qualifying you for incentives from Efficiency Vermont.
It happens all the time that people call and say, “We replaced all of our windows and now we want to do an energy audit and see where we are.” Replacing windows is the lowest priority for a whole bunch of reasons.
Q: Why is that?
A: For the average house, 15 percent of the walls are windows. If you replace all the windows, say you go from a single pane with a storm to double pane, you might go from an R-value (heat flow resistance) of 2.5 to a 3.5. But your exterior walls are R-11 or R-19. You are not changing that much R-value over just 15 percent of the house and each window is going to cost you a lot.
Q: Where should people start instead?
A: Our first priority is to air seal the attic, then to add insulation to the roof. For a flat attic, that usually means sealing around the electrical wiring. If it’s a cathedral ceiling, it depends. If it’s a post-and-beam, we often find air leaks at every beam. You need some caulking around there. Tongue-and-groove ceilings are notorious for air leakage, and that is a different process to air-seal.
Q: What next?
A: The basement. Air pressure in the basement is typically negative, so it is sucking cold air in. Also, in the basement, you need to pay attention to moisture as you make the house tighter. If it’s a stone foundation, we need to cover that with a moisture barrier.
There is the old myth that “you want the house to breathe.” We say, “You want to make it tight and ventilate right.” By ventilating, you can filter the air, which improves the indoor air environment and mitigates problems like asthma or indoor allergy.
Q: Are there simple steps that homeowners can do themselves to tighten up their home?
A: Things like putting foam gaskets over your outlets or caulking around your window are really not going to save you a lot of energy. It will save a little bit, though, so if your labor is free and the caulking is cheap, then economically it will be worth it. Also, insulating your basement can help, particularly the band joist around the top of the basement wall. In older homes, the bulkhead door is often a huge leak. You could also do some weather-stripping around there.
The biggest mistake someone could make is adding insulation to a flat attic and not air-sealing it. At every ceiling light, at every interior wall, you need to pull back the insulation and seal around where the wiring and plumbing goes through. I recommend buying a foam gun and cans of one-part foam. It’s much easier to control than the throwaway cans. You can’t fill a huge void with it, though. That requires a two-part foam with two separate tanks that mix at a nozzle. You would want to leave that to the professionals.
I would also recommend that you wear a good-quality dust mask and gloves when you’re working around cellulose or fiberglass. Avoid an older type of insulation called vermiculite because it most likely contains asbestos. You don’t want to disturb that. Google it and you will find all sorts of images.
Q: Has the new statewide incentive program increased demand for heat pumps?
A: Yes, and the equipment costs are coming down. There are also a lot of other incentives for homes and small businesses if you do the energy audit first. Reducing air leakage by at least 10 percent and addressing health or safety issues, the incentive is $500 for a homeowner and $750 for a small business. If you seal more, you can get a higher incentive, up to $1,000.
Q: Is there any other advice you have?
A: I’m running into a lot of builders who either claim or actually don’t know that Vermont has an energy code that they are required to follow. I also see contractors building homes that follow the letter of the law of the code, but not the best practices. Vermont has an energy code. New construction or renovation of any home or business is required to meet it. I suggest that homeowners make sure that their contractor has the energy code. It is available on the internet or Efficiency Vermont can mail you a copy. They will offer you support on following the code and incentives if you want to build above the code.