The latest achievements of research into human induced climate change have led specialists to the conclusion that the World needs a fundamental reboot. Major measures are needed in all sectors to avoid global catastrophies. Although much has been done already to reduce the environmental impact of the built environment in the last twenty years, there is still a huge scope and a great need for further improvement in this field. Newly emerging technologies such as nanotechnologies, as well as a deeper insight into the metabolism of buildings and urban settlements are the keys to a wider use of renewable energies and a drastic reduction of buildings' dependence on fossil fuels.