© 2016 Z. The UK Government estimates that approximately 22 TWh of energy can be saved from English dwellings by 2020 from a range of fabric and heating energy efficiency retrofits. Yet the rate of retrofit uptake has been less than is needed to meet government targets and the retrofits impact on energy demand has been less than predicted. Two questions that must be addressed are: who have (and have not) taken up retrofits and what household factors affect this; and, what impact have these retrofits had on energy use and how does this differ among households. The purpose of this study is to provide a better understanding of the uptake of energy efficiency retrofits and the resulting change in energy demand. A cohort of 168,998 dwellings gas-heated English dwellings was used to examine retrofit uptake from 2002 to 2007 and the change in gas use from 2005 to 2007. The findings show that retrofits do have an attributable impact on reducing energy demand and that combining retrofits displays a dose-response like effect, after controlling for household and dwelling factors. Energy savings play a central role in meeting UK climate change mitigation targets and therefore understanding the take up of energy efficiency retrofits and their impact on energy demand and variations in these retrofits across the population is vital to understand their potential.