When we had our local utility representative visit a few weeks ago to explore switching from oil to gas heat, he told us that one of the best energy-efficiency investments we could make was home insulation. So, in my seemingly endless quest for comfort and economy, I decided to call a nearby insulation specialist see what he had to say. I learned a lot.
Most heartening for our pocketbook was the news that we would save 30-50% on our heating bill if our house were properly insulated. Based on our 2007-2008 heating oil expenses, that would have been an $800-$1,300 annual savings.
Our house was built in 1924, so there are several inches of space with no insulation between the inside and outside walls. It's amazing that we stay as warm as we do. Our visitor told us that we have an R rating of 2, and that with proper insulation our R rating would be 16. I learned that when you're talking insulation, an R rating has nothing to do with movies; rather it's a measure of thermal resistance. The higher the R rating, the better an insulation's effectiveness.
So, I needed to know what the best insulation would be for our three-story, roughly 2,400 square foot, Dutch Colonial house. Our visitor installs fiberglass, cellulose or foam insulation, so he was an experienced, seemingly impartial source of information. He told us that foam wouldn't be appropriate for the first or second floors or the office room on the third floor. It's used to spray onto surfaces, not to spray between walls. Foam, if sprayed between walls can actually make a wall bow out—not a desirable look!
Fiberglass is another option, but not for us. We were told that fiberglass insulation is great to use when a house is being constructed, but not so good to use in a house already standing. The fiberglass tends to stick to the nails and clump up when it's applied after the house is built.
That left us with cellulose insulation for the main body of the house. It's basically old shredded newspaper (make sure they use recycled paper) that is treated with fire retardant. Our installer said cellulose provides excellent heat retention. I also like this option because recycled paper requires much less energy to produce than fiberglass or foam.
The workmen put 1 ½ inch holes in the walls on the outside of the house where possible and on the inside when they can't get proper access from the outside. Then, they blow in the insulation. They plug any exterior holes, so you cannot see any signs of their handiwork. Interior holes have to be spackled and painted or papered over by the homeowner. Insulating the first and second floors of our house, which is a total living space of 1,800 square feet, would cost us $4,875.
Insulating and cleaning our cinderblock basement crawl space (it's under a powder room on the main floor that gets very cold) with foam would cost $1,395. Fiberglass was the choice for the third floor attic space, and that would add another $2,875 to the bill. The total is over $9,000. We think this year we may forgo the attic, but we need to decide if we should go ahead with the second and third floor living space, or the crawl space which affects the temperature in the bathroom directly above it. The $4,875 for the living space still sounds like a lot, but it hurts a lot less when we think of the money we'll save on next year's heating bills.
There may be another way to save some money. We were told that for an additional cost of about $250 we could have a professional energy audit. In New Jersey the cost of the audit is currently refunded by the NJ Clean Energy Program. The insulation work also could entitle us to a significant rebate from the NJ Clean Energy Program of between 10% and 50% of the total cost, as long as we spend at least $2,500. Sounds great. But, that's another story for another day.
If you want to learn more about home insulation, there are many good websites. In New Jersey, www.njcleanenergy.com is very informative. Another useful site regarding mostly fiberglass insulation is the North American Insulation Manufacturers Association's site.