The aim of this report is to provide insight into past developments for energy use, energy efficiency trends for households and tertiary sectors in EU countries. This should help policy makers and other parties involved in energy efficiency and CO2 emission reduction in adapting present policy and formulating new effective policy measures. The main issues in the analysis are energy efficiency improvement and the effect of various policy measures. However, energy trends including autonomous energy savings and the effect of other factors, such as the impact of economic growth, energy prices and behaviour, are also part of the analysis. This publication relies on data contained in the ODYSSEE database on energy efficiency indicators, with data on energy trends, drivers for energy use, explanatory variables and energy-related CO2 emissions.