I was wrong. I previously argued that subsidies for home insulation are an expensive way to reduce carbon dioxide emissions. The SEAI has now release a post-hoc assessment of the Warmer Homes Scheme. The executive summary puts a brave face on, but if you have a look at the detailed results, you soon discover that the Warmer Homes Scheme seems to have had no noticeable effect on fuel use (and hence emissions), poverty, comfort, or health. Most results are insignificant, a few are significant with the right sign, and a few significant with the wrong sign.
One of the striking results is that the control group (without subsidies) have put in about as much insulation as the intervention group (with subsidies).
The research is not brilliant, so perhaps there is more to it, but for now the conclusion must be that the Warmer Homes Scheme is an expensive way to achieve nothing.
The SEAI should be praised for studying the impact of their interventions and for publishing the results.