According to the directive on energy end-use efficiency and energy services (ESD), the European Member States shall adopt a national indicative energy savings target of 9% (or beyond) in 2016. The issue of the energy savings evaluation is crucial for its implementation. The French White Certificates (FWC) scheme is one of the important measures for France to fulfill its ESD target. However, the accountings of energy savings in the FWC scheme and in the ESD are different. Therefore, an analysis of the consistency of the two systems is needed. A concrete example of actions on residential buildings is used to illustrate the challenges for policy marker and stakeholders to set harmonized evaluation rules. The FWC and ESD calculations appear to be consistent from a physics point of view, as long as calculations are well-documented. But due to differences in the policy objectives, calculation routines may be necessary to convert national energy savings unit (e.g., kWh cumac) into supranational energy savings unit (e.g., ESD kWh). Finally, the work done to establish a transparent evaluation system brings additional benefits (e.g., increased visibility and quality of the actions), which will improve the results of the energy efficiency policies on long term.