After the oil crisis in the 70s energy regulation codes were implemented, but a great portion of existing dwellings have not been retrofitted to current requirements. To face this issue several actions were taken in the European Union (EU), among these, the implementation of Energy Performance Certificates (EPC), which include a Recommendation List of Measures (RLMs) to retrofit buildings. Some concerns exist about the lack of confidence on these recommendations. The main objective of this study is to analyze the usefulness of the EPC, answering if it is possible to deliver a realistic financial assessment about renovation strategies using these tools. The study is based on three indicators: Consumption, energy saving variations and profitability. The study is based on a renovation project case study, where simulations and Life Cycle Cost Assessment (LCCA) were performed, in order to identify the different results that EPC's and an energy efficiency assessment could lead to. The results show important differences in all the concepts evaluated.