Europe is going through a great social, economic and environmental period of transition. The changes the EU is currently undergoing have been causing increased awareness about sustainable development, natural resources use and energy efficiency on the agenda at the European level of policy making. However after more than forty years of the series of ‘Earth Summit’ conferences under UN Environmental program (UNEP) such as Rio 1992, Rio+5, Johannesburg 2002, Copenhagen climate summit 2009, Earth Summit 2012, the path towards sustainable development has not yet been clarified and is far from being achieved. Virtually all cities share concerns for the state of their environmental outlook. The relatively new problem of planning for urban energy efficiency emerges in this transition process. This will require substantial and concerted shifts in social–cultural, economic and environmental subsystems of cities. This paper presents a critical review of the literature on the context of urban energy efficiency and particularly on the ‘structural’ aspects of this issue. Our aim is to understand the larger context for planning for energy efficiency in Europe and clarify what the substantive content of planning for sustainability is. This means also understanding the functional-structural nature of urban energy regimes on which planning acts. Moreover this paper seeks literature to build up an understanding of what makes the city of today structurally unsustainable. The paper outlines crucial background issues in relation to energy efficiency and begins to outline a framework for further studies.