Sustainable construction requires an integrated planning process, as energy efficiency, indoor climate (temperature, air quality, light, and acoustics), resource utilization, and durability must be optimized. To meet these challenges, the laws of building physics within and around the building must be understood and applied, often using approximation solutions. Optimal use of our resources with minimal energy consumption and minimal environmental impact is crucial to achieving the best possible comfort and maximum safety for the residents or users of buildings. This book addresses the interactions between buildings and heat, moisture, air flows, light, and sound. The following topics are covered: outdoor climate, indoor climate, steady-state heat transfer, sun protection, and thermal bridges.