Energy efficiency delivers energy savings and therefore energy cost savings, as well as direct environmental benefits. Besides, as an indirect effect, it has smaller or larger consequences on other economic values. This report reviews current knowledge about the impact of energy efficiency improvements on the value of buildings. In particular, the methodology that can be applied to quantify the increase or decrease of property value linked to the energy performance and sustainability components is explained and different methods are compared. Secondly, the report demonstrates the impact of energy efficiency on the payment default risk namely the link between energy efficiency investment and ability of borrowers to repay their loans.