Book excerpt: This book explores how energy efficiency is a major component in the development of sustainable real estate. Efficiency is one of the most frequently-mentioned aspects of government policies for green building design in the United States and around the world. There has been a significant amount of effort devoted to the creation of green practices in real estate, including building construction, building assessment, city planning, investment, governmental regulation and policies, and industrial development. One of the key emphases of the above activities is energy efficiency, thus it is crucial for researchers and readers to have a comprehensive overview of the topic, as this book provides.