Guest editorial note
This special issue is produced in co-operation with the European Council for an Energy Efficient Economy (eceee). Within it, we present current findings on a broad range of energy efficiency policies and measures. Starting with a series of papers dealing with energy efficiency within the wider energy system, we then move on to other papers focusing on buildings and appliances and their respective policies and measures. Many of the papers highlight the consideration of the human factor in policy design, modelling and technological development. The discrepancy between modelling, testing and real life is in many cases a major challenge. A common theme in many of the key energy efficiency policy and practice questions today is how we deal with increasing complexity. This may be the technical complexity of deep refurbishment of a building; the market complexity of delivering retrofits involving multiple trades or the need to think more widely about a part of the energy system so that the outcome of policy and practice across a range of different interests can be optimised.