Cities represent the places with the highest environmental and energy impact in the world. Transforming them in a sustainable way has the potential to reduce the pressures of these areas. The building stock could be the driving force behind the energy transition of cities. With this in mind, understanding the priorities of undertaking a massive green regeneration operation becomes crucial to optimizing the use of public funds such as those of the National Recovery and Resilience Plans (NRRPs) that EU Member States have at their disposal. For this purpose, a multi-criteria ELECTRE TRI-B (ELimination Et Choix Traduisant La REalité TRI-B) model was used to provide useful information in prioritizing intervention on the existing building stock to achieve the sustainability targets set at European and international levels. The model was tested on a real case study located in Turin (Italy) to improve the management process by classifying intervention on a building stock characterized by different typologies and construction periods. Looking at the results, the retrofit operations with the highest priority relate to the apartment building sector from 1946 to 1970 and the multifamily building sector from 1919 to 1960. Despite the high initial investment requirements, an ecological transformation of this stock would result in significant reductions in health impacts, more green jobs, and lower resources consumption. The model is useful for managing public policies in this area by providing guidance to the project manager on how to proceed in the provision of ad hoc funds and could optimize the process of local community energy generation.