Zero emission during operation - this has to be the target for buildings in the near future. This book approaches this goal with the application of the thermodynamic concept of exergy to the built environment, allowing new design and technology concepts that go beyond mere 'energy saving'. This approach reopens rigid passive design paradigms and offers more architectural freedom while ensuring the high performance of buildings. By introducing new approaches for the understanding and analysis of building systems and the dynamic interaction between the active and passive elements of a building, it describes key components required for LowEx building systems. The building cases analysed cover climates as different as the moderate climate of Europe and the hothumid tropics of SouthEast Asia and provide detailed investigation of both the conceptual and deployment details.