Energy audits save renovation headaches

By Tom Gocze, BDN Staff
Posted Nov. 19, 2010, at 11:45 p.m.

Last week someone told me about their old house. It has been an ongoing project for the past 20 years or so. The focus of the work was to cut the heating costs. It has been insulated, had new roofs and windows installed, and it still eats a lot of wood and the roof leaks.

The question posed to me was whether they could give it up and if they could build a new energy-efficient house for under $55,000. The answer to that question is yes. But the longer, less expensive answer is to fix the broken house that they are living in.

Twenty-six years ago, oil was only 80 cents a gallon when I got my energy auditor’s license, and there were not many auditors.

Today with oil pushing $3 a gallon and tax credits all over the place, we are awash with energy auditors. My first suggestion is to get an energy audit. There is no reason to avoid this minimal investment that will help diagnose all the problem areas.

For the benefit of our readers, we can probably get to the root of much of the problem without even looking at the house. This is not because of any great gift or knowledge, other than experience and understanding of what many people miss when doing renovation work.

It is likely that the walls were opened up and were filled with fiberglass batts. Fiberglass is a decent insulation, but it also is used as an air filter. Air will pass right through it if given the opportunity. A wall insulated with fiberglass must be airtight.

Many people miss this point. A fix that I like is simple but not inexpensive: Wrap the exterior of the house with a minimum of 2 inches of foam insulation. This requires removing the siding, installing the foam and re-siding over it. It will require moving the windows out 2 inches to be even with the new exterior surface, but this will afford you the opportunity to seal the windows properly, which I suspect was not done. For years, replacement window installers would tuck in fiberglass to seal the gap between the window and the window opening. This has to be done with foam or caulk.

Air leakage can kill any energy renovation project. An energy auditor can demonstrate this with a simple blower door test. It will show you the holes in the house, and they can then be sealed.

Another educated guess is that the attic is riddled with holes. More specifically, the ceiling below the attic is probably full of holes. There are always penetrations for lights, plumbing vents, chimneys, attic hatches and wiring inside the walls that are under the attic. All these holes open a sizable path for warm air to escape. That escaping warm air will take moisture from the house and deposit it on the inside of the roof. This moisture can freeze during winter and thaw on warmer days, leading the inhabitants of the house to think they have a roof leak. This is simple to fix, especially if there is not much insulation in the attic. You move the existing insulation out of the way and seal the holes with canned foam, spray foam or caulk if the holes are small enough. There are always gaps around chimneys that must be sealed. These can be very large holes. Here, we need to pay attention to the fact that chimneys can get hot. They must be sealed, but we must maintain a 2-inch clearance to any combustible materials.

Did I mention that roof insulation should be around R-50 and walls should be a minimum of R-30?

All this work should be way less expensive than building a new house. The same procedures should be followed when building a new home. There is no guarantee that this will be done right with a new house, even though it should be. Codes are only slowly recognizing the true costs of poor energy design.

If you are having a new home built or are purchasing one, it is not a bad idea to have an energy audit done as part of the purchase agreement.

Questions for Tom Gocze should be mailed to The Home Front, Bangor Daily News, P.O. Box 1329, Bangor 04402-1329.

http://bangordailynews.com/2010/11/19/living/energy-audits-save-renovation-headaches/ printed on September 22, 2014