Germany is struggling to get people on-board with a green energy movement that involves banning high footprint domestic heating systems (e.g. gas boilers)-- thus forcing people to migrate to heat pumps. A low-income family who was interviewed said it would cost €45k to install a heat pump in their terraced home in Bremen.
That price tag sounds unreal. I am baffled. What’s going on here? I guess I would assume an old terraced German home would likely have wall radiators that circulate hot water. Is the problem that a heat pump can’t generate enough heat to bring water to ~60°C, which would then force them to add a forced-air ducting infrastructure? Any guesses?
(note the link goes to a BBC program that looks unrelated, but at the end of the show they switch to this issue in Germany. I’m not sure if that show is accessible.. I see no download link but that could be a browser issue)
We have a house from the 1920s. The isolation in these houses are non existent or minimal. I isolated things i could access like the roof. But still i can really isolate the walls because since they are double walls (2 walls with a space between them) there is a lot of debris on the bottom which has to be cleared before they could be filled with isolation (expensive) if thats even possible if not (in our case it isnt) then i would have to put isolation on the outside which is a min of €20k. And i would have to isolate the floor another €8k and even then the house isnt 100% isolated. Then the cost of the heatpump which is about €10k to €15k in our case. And then if i really want off gas i also have to do some sort of boiler for water which i dont really have space for. So all in all it would be cheaper to build a new house then to retrofit my 100 year old house. And there are a lot of old houses here. Heatpumps in its current form are just not feasible for “normal” people.
Cavity filled insulation is very common and relatively cheap. I know people who did it themselves with an expanding foam gun and multiple cases of foam.
If you have a cavity, which a house from the 1920s probably doesn't have.
They sometimes do, but some of these older brick houses use lime mortar which is far more breathable. Allows moisture in and out. Some older houses are also not that water tight anyway or often have moisture issues.
If you use the wrong foam, it absorbs that moisture. Bad. Think mouldy sponge. If you use the right foam, but don't ensure ventilation and tackle moisture issues? Still bad. If you don't mix the foam right or use too much? Possible structural damage. Or the foam's flammable which is an issue in an old house with old electrics.
The person you're responding to mentions people doing it themselves with an expanding foam gun, which as someone who worked in the industry gives me the shivers tbh. I mean, maybe they'll get lucky, but I wouldn't buy that house. If they used the wrong foam or did it wrong, it's not as if you're going to be able to remove it or start over. It's there forever now.
He specifically stated he had a cavity. If you don't you can do external cladding insulation and internal insulation.