Comparison of internal and external insulation: Is external insulation significantly better?

yes, exactly those are also my current considerations (and I mourn with you).

clear, but after interior or exterior insulation that would no longer be the case. But I shouldn’t put anything in front of the wall heating (or should I?). I have plenty of room height, but I can’t yet foresee the effort involved in retrofitting underfloor heating under the plank floor. But I will probably accept that, it’s for the next 100 years.

I don’t consider it sensible to make old planks suitable for underfloor heating afterwards. If you are "anyway" getting clay plaster inside, I would seriously consider wall heating. (I have personally had it for a year, my brother for about 15 years). However, without clay in our case :oops:

I don't think it makes sense to retrofit old floorboards for underfloor heating. If you are "anyway" getting clay plaster inside, I would seriously consider wall heating. (I have had it personally for a year, my brother for about 15 years). However, without clay in our case :oops:

...would you like to share a bit about your experiences with the wall heating? How much area do you have compared to the living area/ to the built-up space?

ok, I will take a closer look at the option "wall heating" (and I am curious about your response to the inquiry from ). thank you very much! So you didn't do anything on the outside? Yesterday, I watched the YT video "Internal Insulation II" by "Energy Saving Commissioner" (before the comments come in: I already know that I need to get more information besides YT videos, in particular, I will also have an energy consultant come...), from about minute 10 it says (summary):

[*]water and thus frost have penetrated an old, porous brick wall over the years; nothing can be corrected here with "simple means"; [*]from minute 11 the possible measures are mentioned: applying a plaster or a cladding; [*]or hydrophobization (sealing of the masonry).

You obviously did not do this, and still had good experiences. My wife also asked this morning immediately why a cladding with bricks ( means here: facing bricks) is splash and frost resistant, but the retention of the old brick masonry as the exterior masonry is not. Well, perhaps it is due to the many holes / capillaries that have eaten into the old masonry over the years?

The walls are approximately 3 and 4 meters long and 2.55 meters high with about 65 square meters of total living space. The bathroom has tiles and underfloor heating and is just over 9 square meters in size.

You didn't do anything on the outside then?

Hi! Yes, the old joints were ruined because ivy had eaten into them for decades. We had the facade sandblasted first. Then I removed all the joints with a chisel hammer and scraped everything out, then reset and mortared all the loose stones. That took a few days. Afterwards, we had the house re-jointed – and that turned out to be much cheaper than expected. Finally, I impregnated everything. So yes, the facade was renovated. But we would have had to do that even without the interior insulation. It was always important for us that the work could be done by ourselves, including the interior insulation, which was also a decision criterion. If you have clinker bricks, it won't be rocket science to remove the joints. And maybe it’s necessary anyway?

You obviously didn't do that, and yet had good experiences. My wife also asked this morning immediately why a cladding with bricks (@11ant means here: facing bricks) is splash water and frost resistant, but keeping the old brickwork as exterior wall is not. Well, maybe it’s because of the many holes / capillaries that have eaten their way into the old masonry over the years?

Hehe, who should eat the holes into it? - the stone louse is a hoax. Frost causes bursting, it doesn’t create capillaries. A facing masonry shell sits (usually with a gap) in front of the structural masonry shell, so it’s not part of it, with the consequence of no shared moisture balance. Overall, I would tend, after various rounds of Cognac over the pros, cons, etc. to sandblasting, sealing and re-pointing and interior insulation. If I’m not mistaken, the energy saving commissioner also acts individually and constructively in an advisory capacity, so he is not a damage-complaining expert and certainly not a semi-knowledge entertainment YouTuber. Therefore, I am confident that one can also get a reasonable, well-planned proposal from him. Online I find a “service radius of 50 km around Darmstadt,” but I think that a trip from SU to DA (about two hours driving time) would be worthwhile. However, I have not personally met him yet.