The objective of the urban development project POLYCITY supported by theEU-programme Concerto is to reduce the consumption of fossil fuel through49,50energy-efficient buildings and the increased use of renewable energies. Thescientific research conducted within the framework of this project focuseson innovative energy saving technologies.The findings of the POLYCITY project are published in this book which thusoffers a wide range of practical experiences and comprehensive informationabout innovative energy concepts and performances.The POLYCITY project supports different aspects of urban development inthree European cities: new buildings in the peripheral area of Barcelona,Spain; the renewal of an old discrict in Turin, Italy; and a mixture ofredevelopment and new building in Scharnhauser Park, a former military areaclose to Stuttgart, Germany.This best practice book about sustainable urban energy concepts is worthreading for architects, engineers and urban planners.