The built environment in Europe accounts for around half of all energy use across the community. Therefore, drives to improve the sustainability of Europe and its member states have contained numerous initiatives and mechanisms through which energy use and carbon emissions can be reduced. It is important to remember that the built environment is far from homogenous, though, and that the buildings and structures already existing require a variety of approaches. It can also be argued that energy used through the constructed environment is driven by the people inhabiting and using buildings. Therefore, significant efforts have been made to explore and influence human behaviour with regard to sustainable lifestyles. It is also true that buildings exist as part of a wider landscape, rather than in detached isolation. Therefore, various initiatives have attempted to identify such connectivity, and to explore how emerging technologies can begin to drive sustainable changes. This chapter presents an overview of strategies which have developed across Europe, and discusses the responses which can be witnessed at the national and local levels.