This document looks back at 50 years of energy efficiency policies in the European Union (EU) specifically focused on buildings. It shows how EU policies have evolved since the 1970s to reduce energy use in buildings. These policies include rules like the SAVE Directive and the updated Energy Performance of Buildings Directive. The review discusses how these policies have pushed for better energy use in new and existing buildings. It also talks about successes and where challenges still exist in making buildings more energy-efficient. The paper highlights how changing political goals have shaped the way the EU tackles energy efficiency in buildings. Through these policies, the EU has made progress in saving energy, but there's still more to be done to maximize energy efficiency in buildings.