This guide will help contractors and homeowners identify ways to make their homes more comfortable, more energy efficient, and healthier to live in. It also identifies the steps to take, with the help of a qualified home performance contractor, to increase their home’s insulation, ensure healthy levels of ventilation, and prevent moisture problems. Contractors can use this document to explain the value of these insulation measures to their customers. The references in this document provide further explanation of insulation techniques and technologies.