Is it possible to renovate a residential house from 1954 into an energy-efficient house? How?

This is probably not expected here either. For one person, a house with corner windows and walk-in showers is important, while for another it means more that the house has belonged to the family for a long time. The house certainly has more originality than painting it with crimson wall projections or Smokey Eyes on a run-of-the-mill house. I consider a surcharge in the form of a non-minimum price to be acceptable. However, I expect several months of own work to undo old conversion and extension measures.

No, this is really not expected, although we definitely cannot do everything ourselves either.

We will now wait for the cost estimates and then decide where improvements are needed or what can be cut.

Best regards, Basti

We are currently sitting together and pondering what to do with the insulation. The main house is cavity wall construction where blown-in insulation would work well; the annex is simply constructed but already has 8cm of insulation on it. Now a room in the main house is supposed to be combined with a room in the annex to become one room. How does that behave with the different thicknesses and types of insulation and the temperature?

Best regards, Basti

the extension is simply constructed but already has 8cm of insulation on it.

How do things look with more recent plans in general, and which changes from the original state are even documented and preserved?

Now a room of the main house is supposed to become one room with a room of the extension. How does it behave there with the different thicknesses and types of insulation and the temperature?

Roughly estimated, one will probably try to match the thermal transmittance values. With U-value calculators, you can aim quite precisely.

yes, unfortunately there are no more recent plans and it is also not documented, it just wasn’t that important during GDR times when the Feierabend Brigade was at work
I don’t really know much about the U-value stuff, I only started reading up on it a bit today.

So today I would like to provide some pictures of the exterior view so you can get an impression. South side West side with extension North side East side entrance veranda East side veranda, supposed to be removed

Best regards, Basti

I haven't read the first 20 posts, but I want to say: the veranda should stay! The house looks cute and cozy. And the veranda is totally underrated. You can overwinter plants there, sit comfortably on cooler days, or shelter the grill. There is also enough space for a terrace. Think twice about tearing it down...

Unfortunately, there are no more recent plans and it is also not documented,

Then you have to do a current survey there, at the beginning also sketches and amateurish ones are fine. Hopefully there are still some witnesses of the conversion who can be interviewed – that also helps.

I haven’t read the first 20 posts, but I just want to say: the veranda should stay!

That is probably what you call a causal connection. The veranda itself may have its advantages, but: while the Kern-Haus is old-fashioned but solidly designed and the rear extension is probably quite decent (though certainly upgradeable for a Kern-Haus regarding today’s thermal insulation), the veranda extension, as far as I can assess from the pictures, is a mess that even westerners could have botched at this level.