Improving the energy efficiency of homes is a key element of the UK Government’s energy and climate strategy which in 2005 were responsible for 28% of total UK carbon dioxide emissions. However, despite the Energy Efficiency Commitment (EEC), which requires UK electricity and gas suppliers to meet targets for promoting household energy efficiency, and the efforts of the Britain’s network of Energy Efficiency Advice Centres (EEACs), household adoption of established energy efficiency measures has been slow. According to the Government’s Energy Efficiency Action Plan, this slow adoption is due to three main barriers – up-front costs; lack of information; and hassle and disruption (DEFRA, 2004). However, other research (e.g. Guy and Shove, 2000) has shown that peoples’ motivations and actions concerning energy efficiency are often more complex than these barriers suggest. Also, even if householders adopt energy efficiency measures, they may not use them in an energy-saving manner. This report gives the results of a study carried out by the Design Innovation Group at the Open University (OU), in collaboration with Milton Keynes Energy Agency (MKEA) and the Energy Saving Trust, that aimed to investigate in detail the drivers and barriers underlying UK householders’ decisions to install – or reject –four important energy efficiency measures (loft insulation, condensing boilers, heating controls, energy-efficient lighting) and users’ experiences of the measures once installed, including their views on rebound effects. Data was gathered during 2006 via an online questionnaire linked to the websites of the Energy Saving Trust (EST) and a BBC/OU television series on climate change, which produced nearly 400 responses. We also gathered respondents’ ideas for improving the energy efficiency products and systems. The data was supplemented by the results of in-depth telephone interviews with householders. The surveys of household adoption of energy efficiency measures presented in this report form part of a larger project entitled ‘People-centred ecodesign’.