My husband and I looked at this book, among other, when we were investigating improving our home’s energy usage and found this book to be the most helpful. At the time we were confused about the different options that were available to us and this book broke everything down and explained what it was and what its use was. This book was invaluable to us when we were making our decisions about what to do. Anytime we had a question we went to the book. This is a good resource for someone wanting to make changes in energy use to their home.