One central aim of climate change mitigation in the European Union is to reduce energy consumption in the housing sector. In order to ensure effectiveness of policies targeting household energy conservation, it is important to investigate existing energy practices of different social groups. This article describes and explains energy practices in three leading states in environmental politics, technological innovation, and support for renewable energy production: Denmark, Austria, and the United Kingdom. Based on a longitudinal analysis of housing utility costs from the European Community Statistics on Income and Living Conditions we show that income plays a central role in households’ energy practices. While high-income households have higher overall energy consumption, low-income groups spend a larger share of their income on utility costs. The variation of energy consumption across income groups is related to household characteristics, characteristics of the dwellings, and cross-national differences in the housing sector.