This book is great.....the author covers soo much information not just zero energy design, that is why the book is so long. He talks about the history and evolution of how we use energy and build homes. He talks about how alot of houses that claim to be green are really not. He talks just about everything from politics, to technology, our pending energy crisis and more. I can tell he is very passionate and knowledgeable in this field. He built a zero energy house in the 70s and lived in it. Even though the book is extremely long..about 800pages...I liked reading it because it talked about topics that interested me. It did provide lots of information also on zero energy design. However...even after reading this book I think most people would still need his help or an experts help to ensure the house is built the way he describes it. However it provides so much valuable information and tips and ideas ...I definetly reccommend it.