This study aims to evaluate the relationship between the carbon footprint produced by the energy improvement of the building envelope, assumed as the technological component that most affects the over-all energy performance of the building, and that embedded in the materials of which it is assembled. The purpose of this research is to observe the relationship between the reduction of impacts due to the operational phase and the variation of impacts incorporated in the materials and components used to obtain these benefits, including the effects induced in the overall environmental performance of the entire process