Stabilize basement wall for extension

The exposed part looks like the base / ground floor. Get the building file, otherwise you can't compare such random checks with the plan.

That is already the basement wall. The basement sticks out about 1m from the ground. I will look for plans from 1948 tomorrow.

The structural engineer writes that if DIN 4123 is observed, the excavation would not be a problem. However, DIN requires excavation in sections. So, not everything at once after all.

It looks as if the ground floor should be built up with the same wall thickness (which would be unusual). Were the plans created before the war, and did they perhaps obtain approval / extend validity based on old plans, but then improvised with the post-war situation in the materials market? Where do you even want to extend there?

But you're not asking me now what was secretly done shortly after the war, are you? No one knows anymore. I only know that the building materials come from the Berlin rubble heaps. Ecological recycling already over 70 years ago. Only the mortar was missing, which you can tell from the masonry. The extension is on the first plan "below".

I only know that the building materials come from the Berlin rubble heaps. Ecological recycling already over 70 years ago. Only the mortar was missing, which can be seen on the masonry.

No, that doesn't seem to me to be the whole deviation.

The extension takes place on the first plan "below".

So on the gable side. Show me the ground floor (existing floor plan).

Sorry, but "above" in the plan. The bathroom window will become the door. The structural engineer will come by again next week.