In the Framework of commitments for the cities' transition to a Circular Economy, the term regeneration has many meanings. The most used interpretation of regeneration focuses on the assignment of resources to future generations, preserving and enhancing them through the regeneration and maintenance of physical, environmental, cultural, economic and social systems. Urban regeneration is the process aimed at improving the quality of settlement systems and creating the conditions for sustainable and socially inclusive growth. According to the EU vision, regeneration intertwines architectural and urban dynamics with economic development, social inclusion and environmental protection. It represents a collective opportunity to increase both community cohesion and the capacity to produce innovation. Cities, as complex settlement systems, represent the privileged places of many innovation and experimentation processes for energy transition and improvement of the quality of community life. The paper pursues the objective to contribute and improve the energy transition in the built environment, individuating an implemented approach based on two principles: regenerate established buildings and reduce soil consumption, returning twelve actions of interventions. In the challenge of the energy transition of cities, development strategies aim to combine the relationships between the cycles of nature and the built environment, the cultural system and the social system. Due to the established characteristics and the huge architectural heritage present in Italian cities, inclusive processes of urban regeneration have been introduced in recent decades. They combine the principles of structural strategies of nature with the material culture of the local heritage, highlighting the innovation of cutting-edge energy transition approach.