Insulation and Energy Efficiency
For mid-Atlantic regions, the U.S. Department of Energy recommends insulating to an R-value of 38. The R-value is the measure of the thermal performance of the insulation material; the higher the R-value, the less thermal energy the material will give up per square inch. Materials can lose R-value as they age, but, especially in newer insulation materials such as foam insulations, the loss is minimal.
Homes built prior to the 1980’s almost always require additional and updated insulation. New insulation can easily be added on top of old insulation, provided that the old insulation is not, or has not previously been, wet. Damp areas around insulation encourage mold and/or mildew growth, most particularly in cases where cellulose-based insulating materials have been used. If necessary, a professional insulation contractor can also handle the removal of old insulation in addition to the installation of the new, but a homeowner should make sure that this service has been written into the negotiated work contract.
In addition to a cost benefit and comfort, adding insulation can make a home quieter by reducing the amount of sound carried both within the house through interior floors and walls and from outside the house through exterior-facing walls.