According to the website Utility Bill Busters, as many as one in every three homes in the USA may be underinsulated in at least one area. And that number actually increases with the age of your home.
Older homes, in particular, may be a problem because the insulation used may be less efficient than modern materials, insulation standards were lower or the material may have degraded over time.
Attics are a common problem area, but actually one of the easiest to correct.
Keeping your attic well-insulated will pay off both winter and summer. Heating and cooling make up half to 70 percent of the average home’s energy bill. But adding insulation to the attic is relatively easy and very cost effective.
Insulation is measured in R-values—the higher the R-value, the better your walls and roof will resist the transfer of heat. According to figures from the U.S. Department of Energy, if you have less than 11 inches of fiberglass or rock wool, or eight inches of cellulose, you could probably benefit by adding more.
SLEMCO’s Robert Mitchell recommends insulation values of at least R-30, with R-38 the Design One recommendation for new construction. His recommendations are equivalent to approximately one foot to 15 inches of fiberglass insulation. If you’re a do-it-yourselfer, your building materials supplier can recommend brands that eliminate the itchiness that sometimes made fiberglass insulation so unpleasant to install in the past.