The EC has defined the 2030 climate and energy framework and a target of at least 32.5% was defined for the improvement in energy efficiency. Part of this percentage will be naturally achieved through equipment replacement and buildings refurbishment, but the other part will be more challenging: it will require a change in the way users use energy in their daily routines, both at work and at home. Several projects have addressed this issue and results are more or less unanimous: a temporary change in users’ habits is fairly easy to achieve, but they regress to the initial behaviour just after a few months. It is a case to say that “old habits die hard”. This presentation will be focused on a project that targeted behavioural change in offices and residential buildings in 3 EU member states. It will outline the solutions developed and the main results achieved.