Energy question of the week: How can urban areas efficiently save energy?

Germany is a country of towns and cities. Almost 90 percent of the population lives and works in urban conurbations – from Aachen to Görlitz, from Flensburg to Friedrichshafen. The need for energy is obviously highest where these people are located, and that is the key to achieving a reduction in carbon dioxide emissions. However, what form should intelligent urban redevelopment take, from transport through residential accommodation to workplaces?