The complexity of contemporary society – increasingly a “global village” – can only be addressed through an integrated approach between the different disciplines. Integrated sustainability and engineering represent the key points of the ongoing transformations for the creation of smart cities where urban infrastructures merge with technological and social ones. The need for new interconnections is emerging, which must be sought, recognized and infra-structured through innovation and new technologies, with a view to a 4.0, economically sustainable and energy self-sufficient reality.