Green buildings and energy efficiency have become a very prominent part of civil engineering and architecture. The main objective behind these innovations is to encourage the design and construction of buildings that comply with environmental sustainability and energy efficiency measures. This book discusses the fundamental as well as modern approaches for energy efficiency, environmental quality enhancement, use of renewable energy technologies, and sustainable architecture and designs, etc. From theories to research to practical applications, case studies related to all contemporary topics of relevance to this field have been included in this book. As this field is emerging at a fast pace, this book will help the readers to better understand the concepts of green building and energy efficiency.