The potential of energy conservation is considerable, yet the technically feasible and economically viable measures which could be taken are by no means fully exhausted. This phenomenon is called ＇efficiency gap＇ or ＇energy paradox＇ and generally described in terms of institutional, market-related, organisational and behavioural barriers. The barrier approach may help decision-makers to overcome obstacles, but it tends to limit energy conservation to positive actions and favours technical solutions. Nevertheless, barrier models give an insight to the technical and social aspects of energy consumption and how they are intertwined.