There is increasing concern regarding current energy feedback approaches as they focus on the individual level, and mostly on household electricity, while the bulk of energy use often lies in heating and cooling. The aim is typically to change user routines, which does not bring a long-lasting impact. In our case study, we address these concerns for apartment buildings by looking at housing cooperatives, the dominant form of apartment ownership in the Nordic countries. These cooperatives manage the heating costs in common and therefore have a large potential for energy saving through long-lasting improvements and investments. We also emphasise the amateur nature of energy work within such cooperatives and consider the implications of our field study findings, interpreted through these amateur and cooperative perspectives, for the design of interactive artefacts.