The need to define new methods and tools for rehabilitation projects is influenced by several factors regarding current housing units. These factors include: their temporary nature due to increasingly fragile and inadequate techniques and technologies; rapid changes in the distribution of their functions and the nature of those functions; the end of rapid urban growth; the need to redefine the current fabric and make it more cohesive and, finally, their outdated appearance and lack of general urban quality. The proposed study is a technologically innovative research involving the energy-efficient and environmentally-friendly rehabilitation of the housing units focusing on the relationship between technical/plant requirements, energy and the functional and economic aspects inherent in public residential housing. In particular, a study system was developed based on the principles, tools and actions required to establish guidelines for the requalification of existing buildings. The system was further divided into topic fields and specific proposals. The general technical and operational model developed for the eco-compatible rehabilitation of public residential housing was based on the study and definition of the intervention methods required to improve environmental and energy performance and comfort, especially as regards the techniques, methods and tools used to ensure project control and management.