Poor heat and moisture management are the enemies of durable, comfortable, and efficient housing, and good building design and construction starts with a solid understanding of good building science. Essential Building Science provides a highly visual and accessible introduction to the fundamentals of building science for residential construction. Part one covers the rationale behind high-performance design and the fundamentals of building physics, including thermal dynamics, moisture transfer, and hygro-thermal dynamics such as vapor drive and condensation. Part two teaches the vital critical thinking skills needed to consider buildings as whole systems and to develop thermal and moisture control strategies regardless of the specifics of the design. Case studies and examples from across North American climatic zones illuminate real-life problems and offer builders, designers, and DIYers the insights and tools required for creating better new buildings and dramatically improving old ones. Good science plus critical thinking equals high performance buildings. Jacob Deva Racusin is a sustainable and natural building designer, builder, and educator. He is co-author of The Natural Building Companion, contributor to The Art of Natural Building, and Systems Director of New Frameworks Construction. A Building Performance Institute-certified Envelope Professional and Building Analyst, Jacob is the program director of the Building Science and Net Zero Design Certificate Program at the Yestermorrow Design/Build School. He and his family live in a two thousand square foot high-performance, natural home in the mountains of northern Vermont, where they run a small-scale Permaculture-inspired homestead.