Leopold1904

I suspect this discussion would be better in a different thread, but briefly, I'm thinking of using PU to insulate a couple of attic rooms, which will be outside, as it were, ie, I'll insulate the walls and the floors from the rest of the house. This does mean we will need to be able to walk on the insulation since we use the attic for storage, so PU, I suppose. And of course we won't be unduly concerned about the air quality. I'm still trying to work out the logistics of having an inward-opening door into these rooms since I'll either have to cut off the bottom of the door (don't really want to do that) or have an uninsulated space where the door opens. Or some sort of Heath Robinson mechanism that lifts one of the PU panels when the door is opened...

Is this better insulation than polyurethane? I'm not worried about noise, there is none where we are.

Thanks everyone, I'll have to digest all that. Yes, les primes, we're not (or weren't) tax resident so didn't qualify. Hopefully for future work.

Well I don't know, maybe there isn't one, in the rooms we're renovating we've put in cavity insulation behind plasterboard, but not sure about the whole house... That would cost a fair bit. Windows we don't want change - they're original blown glass which we'd like to keep. But if it comes down to it I suppose we could try double glazing. Not sure if the frames would take it though. Haven't really looked into it since people we've talked to said it would be a shame.

Well, hopefully the builders will be gone soon. 😀

Thanks for the reply. I'd better google "weather compensation"... By emitters, I presume you mean radiators. These are very old big cast iron ones that probably date from when central heating was first installed in the house decades ago. We have bedrooms on the top floor that are only used a couple of months a year. Are you saying we can turn them off in these rooms? Will this not affect the flow of water through the whole system? That's what our engineer says. Yep, 30 cm stone walls. So can we turn the heat down at night rather than off completely? It seems extragavant to have the temperature set at 19° all night and we're throwing off the bedclothes because we're too hot.

Recently purchased a new house in France and just installed a couple of Hitach Yutaki 12kW ASHP. The house is large (340 sqm), old (1830s) and very poorly insulated. We can't do much about the walls or windows but will be insulating the attic. In any case, the pumps have been up and running and our latest electricity bill (for November-December) is more than 2000€. Yes. Now part of this is due to workmen being in the house and external doors open all day, etc., so we're not seriously concerned; but we are slightly concerned. Our engineer (who installed them) has us running the pump 24 hours a day at a steady temp of 19°, and I think that this is not necessary. I've suggested putting it on a timer. He says no, it's going to cost us just as much, if we turn the pump off at night then the cost of reheating the cooled house in the morning will be as much as keeping it warm all night. He says it's also not good for the pump to be switched on and off repeatedly. What's the consensus on this? If there is one? Thanks! Iain.

Hi all, Nice to be here, just bought a new house in western France and looking to green it up a bit. First question is on our heat pump, so I'll post in the relevant place. Iain.