Air sealing is the “must do” intervention before you perform any other insulation measure. It improves comfort, preserves building durability and can even save energy. Air sealing consists of sealing up cracks and holes between the interior and exterior of your home, including those pesky drafts around doors that are often the source of discomfort. While it is fine to do this as a single measure item, we typically encourage homeowners to do it in conjunction with insulation. The reason for this is we oftentimes find that when done as a single measure, air sealing can disrupt existing insulation. Compromising one efficiency measure to obtain gains with another negatively impacts a home’s comfort and energy efficiency.