Older homes often have minimal insulation. This is a cost-effective upgrade in homes with accessible attic spaces. Where accessible, R-44 or more insulation can be installed to reduce heating and cooling energy use. Plan: remove any existing insulation, sanitize the attic and reinstall new insulation to a minimum depth of 16 inches equal to an R-44 rating.
Air sealing of the attic/ceiling areas has a significant benefit and is recommended to be done in conjunction with the attic insulation retrofitting.