It is widely accepted that interventions designed to promote household energy efficiency, like insulation, central heating and double glazing, can help to reduce cold-related illnesses and associated stress by making it easier for residents to keep their homes warm. However, these interventions may also have a detrimental effect on health. For example, the materials used or lower ventilation rates could result in poorer indoor air quality. The present research sought to systematically quantify the impact of household energy efficiency measures on health and wellbeing. Thirty-six studies, involving more than 33,000 participants were meta-analysed. Effect sizes (d) ranged from -0.43 (a negative impact on health) to 1.41 (a substantial positive impact on health), with an overall sample-weighted average effect size (d(+)) of 0.08. On average, therefore, household energy efficiency interventions led to a small but significant improvement in the health of residents. The findings are discussed in the context of the health improvements experienced by different groups of participants and the study design factors that influence health outcomes. The need for future studies to investigate the long term health benefits of interventions designed to promote household energy efficiency is identified. (C) 2013 Elsevier Ltd. All rights reserved.