Demolition/New construction/Renovation/Building on an old basement - ideas & experiences?

Is there a development plan? Often, the roof pitch of the other half of the house must not be deviated from. As the existing structure also shows. I would rather consider an extension and conversion.

No, there isn't. In the area, there are certainly creative solutions for this "preservation of the settlement character"... Everything from Tuscan villas to flat roof & gable roof combinations is included.

Yes, that should also be the case here. In any case, with the neighbors it was only one wall

Then you should first and foremost conduct an inspection with a structural engineer. As interesting as the question of the subsequent use of the basement is, at the very top of the priority list is that the neighbor's house survives your demolition unscathed. From the necessary measures for this, your options for the basement will then emerge.

Anyway, for the neighbors it was just one wall

To be honest, I did not understand this statement: if the party wall from the right is only single-layered, then the same wall seen from the left will not be double-layered either (???)

I had now interpreted it as "at the neighboring semi-detached house," which might have been built simultaneously/similarly. But true, the inquiry makes sense.

As Smialbuddler says. I mean a similar house that the neighbors diagonally opposite demolished a year ago.