This book will guide you through the process of becoming fluent with using the PHPP as a design tool. And even once you are fluent with the PHPP, this book is still a handy reference and well illustrated guide. The PHPP is a key to how the Passivhaus Standard has, in effect, eliminated the performance gap of buildings. So while industry bodies (and individuals) continue to ask why there is a performance gap and how to address it, here is one solution. And it works.