Residential buildings consume about a quarter of all energy (including electrical and thermal) in industrialized countries and emit around 20% of the carbon emissions there. Older and outdated heating and cooling technology causes high energy demand and, depending on building type, secondary causes can include ventilation and lighting. Technology is available to mitigate high energy consumption, and to enable the use of renewable or environmentally friendly energy, partly generated locally. This book, written by international experts from academia as well as industry, compiles and describes several key technologies available to reduce a residential building's energy consumption. Key themes include local energy generation, such as the use of sunlight to reduce heating needs, and photovoltaics for electricity. Case studies are included in most chapters to provide real-world context for the technologies described.