Here's the uncomfortable truth Nicholas lays out in this episode: even when retrofits do happen, they often don't work the way anyone promised. In the UK's flagship Retrofit for the Future programme, the majority of homes used 50% more energy than predicted post-retrofit. The reasons layer on top of each other — the "pre-bound effect" (fuel-poor households were already under-heating, so the baseline was always a fiction), shoddy construction, bad handovers where nobody explained how to use the new systems, and then the "rebound effect," where people finally warm up their homes properly and the promised carbon savings evaporate.

And then there's the middle-income retrofit trap, where programs end up serving neither the fuel-poor (who get grants) nor the wealthy (who can self-fund), but completely miss the majority in betwee ...