If they aren't to be convinced of the cause then there's no choice right? Then your bedroom will just be colder than theirs, and shared spaces could meet in the

If they aren't to be convinced of the cause then there's no choice right? Then your bedroom will just be colder than theirs, and shared spaces could meet in the middle (sofa can have blankets; at dinner there is hot food; at lunch you might need to heat the eating room a bit more). And it depends on how extreme you want to go: 13°C is laudable but I'm trying to do the same and 16-17°C is the limit before I need to put on a real winter coat and actually impair comfort/mobility while working on my computer. And that's with headwear and everything (which I take off for customer video calls, to come across a bit more professionally...). If you'd want to go 13°C then I guess shared spaces might be more towards the comfort side of the spectrum.