The SINFONIA project in Bolzano impressively shows how sustainable urban development can be achieved through the combination of technological innovations, citizen-oriented planning and holistic concepts. The project’s goals and vision go far beyond the technical aspects of energy conservation and the promotion of renewable energy, and seek a comprehensive change in the way we plan, build and live our cities. The focus on partnership and co-creation makes an important contribution to the development of sustainable and liveable cities in Europe. The SINFONIA project is a pioneering initiative to implement large-scale, integrated and scalable energy solutions in medium-sized European cities. With a duration of five years, the project aims to meet the challenges of urbanisation and climate change while improving the quality of life of citizens (European Commission, *Smart Cities and Communities: The European Way*, EU publications, Brussels, 2020).