Q: Jonathan asks: We recently purchased a three-level townhome in Virginia, built about 15 years ago. The third floor, where the bedrooms are located, stays about 5º F colder than the main living area on the second level. There is only one heating zone with the thermostat on the second floor. A heating technician has balanced the ductwork, but said he cannot get more heat to the bedrooms.
A “home energy” company has proposed a solution that involves sealing air leaks in the bedroom ceilings/attic floor, sealing around the chimney, weatherizing the attic hatch, insulating a few roof areas that the builders missed, and adding cellulose to the rest of the attic to bring it up to R-60. They claim that their work should lower our heating bills and make the third floor more comfortable, but will not guarantee any specific energy savings.
They did look in the attic and used some type of infrared thermometer to find cold spots.
The job will cost about $3,000. Does this sound like a good deal to you?
Answer: One of the most common places for energy leaks in newer homes is, in fact, air leakage into the attic through gaps in the framing, holes around pipes and wires, and large openings or “chases” where chimneys, ducts, and other mechanical components enter the attic (see illustration).
Also, it is not uncommon for areas to be under-insulated or overlooked in complex roof shapes – for example, around dormers, level changes, or transitions that make it hard to maintain a continuous air and thermal barrier. Developers and typical insulation subs are rarely experts on building energy details.
So, in general, their proposal sounds reasonable. However, I would want additional information before proceeding:
1) Do they plan to remove the existing ceiling information to gain access to the ceiling. Otherwise it is difficult or impossible to seal all the gaps.
2) Will they use a blower door to locate the leaks? Without a blower door, weatherization is mostly guesswork, with no objective way to measure the results:?
3) Will they perform before and after blower-door tests to measure the change in house tightness? This is the gold standard for measuring the effectiveness of air sealing.
4) Why insulate to R-60 in Virginia. R-38 is the typical recommendation for attics in your area? Savings from additional insulation will be minor.
I would also ask for an estimate of the energy savings, even if they are not willing to provide a guarantee. If this is their business, then they should have energy modeling software as well as real-world experience with similar townhouses.
I wouldn’t expect a quick payback, since most of the “savings” will go toward keeping your bedrooms warmer (and cooler in the summer) rather than cutting back on fuel usage. In fact, it may take well over 10 years to recoup your money based on simple payback (total cost/annual savings).
If you have been turning up the thermostat on the second floor to warm the bedrooms, then you will have a faster payback. There are a lot of variables to consider in this type of calculation, so it is never more than an educated guess.
Also consider your increased comfort in a warmer space with fewer drafts — what is that worth to you? In addition, reducing air leakage into attics also lowers the chance of attic moisture problems and ice dams in cold climates. Some factors to consider are:
1) How long do you expect to remain in the home?
2) How might the weatherization work affect resale value?
3) Do you have a fireplace or a gas-fired furnace or water heater? If so, ask whether the air-sealing could possibly lead to spillage of flue gases or backdrafting. These are concerns mainly with traditional fireplaces and with gas appliances that vent “atmospherically” without fan-induced venting.
Finally, check references and talk to former clients. Were they happy with the results? And get a second bid – it never hurts and could save you a lot of money. Also energy work is often invisible to the homeowner and difficult to evaluate so a second opinion can be valuable.
Getting an opinion from someone that is not selling you anything can also be valuable. Many towns and cities offer free or subsidized energy audits that could provide you with unbiased recommendations.
For more information, download the EnergyStar Guide to Sealing Air Leaks and Attic Insulation.