Analysis of the technical potential for energy efficiency often highlights very large potential savings; however, the reality of savings achieved often falls far short of this potential. Ex-post analysis is known to be important for quantifying realised energy-efficiency savings, but is often neglected for many reasons. This paper describes an approach to an ex-post analysis that uses readily available administrative data and provides insights into the impact of an energy-efficiency policy measure of residential energy-efficiency retrofitting (upgrades). Ex-post analyses have the advantage of including the impacts of events and behaviours that coincide with energy-efficiency programs and thus facilitate disentangling external influences and avoidance of misattribution of savings. Three different quantitative approaches are used to determine whether the national energy-efficiency retrofit programmes or the economic recession was responsible for the sharp fall in residential space-heating energy demand in Ireland between 2007 and 2012. The analysis finds that while Government energy-efficiency retrofitting programmes have played a role in reducing energy consumption, the biggest influence by far between 2007 and 2012 was the economic recession. The top down decomposition analysis recorded energy savings (including ‘savings’ that were due to the recession) that were 3.9 times greater than bottom-up retrofit savings related to residential space-heating measures over the period 2006 – 2012. The analysis highlights that an important policy challenge is to achieve reduced consumption due to behavioural changes while experiencing economic growth.