The issue of public policies relating to changes in sustainable consumption has recently been raised in France and was a point of focus during the "Grenelle de l'Environnement", a consultancy and decisionmaking system bringing together, for the first time, environmental NGOs, companies, trade unions, members of parliament and government officials1. However, since the 1970s, France has been faced with the issue of behavioural changes in energy consumption. This chapter proposes to examine the question of the behavioural changes driven by energy-saving policies in France. In particular, the recent history of energy-saving policies has led to the emergence of the "consumer citizen" in relation to market-framed policy devices. Yet analysis of certain public policies (using energy-saving light bulbs for lighting, thermal renovation via the sustainable development tax credit) shows that whilst frameworks for consumption behaviour can be quite effective when it comes to designing policy, there are shifts and "spill-over effects" in the interlinking and confrontation between the figure of the "consumer citizen" and the actual practices of households and of all the actors involved. Finally, energy practices in French households demonstrate a multitude of social logics either favouring or restricting energy-saving practices, both within "concerned" social groups and amongst the "general public", where the environmental argument is far from being a pertinent indicator of "energy care". A better understanding of the social mechanisms at work in energy practices and norms would provide new fulcra for public policies, which are too often based on a conception of homo economicus/ecologicus, designed to maximise his financial and environmental utility, with no consideration for the contradictory imperative embedded therein.