Duration until the issuance of the building permit in BW

I only have the building permit, but financing is not yet in place because I would need a contract and KfW confirmation for that, which I have not received to this day from the company I wanted to build with...

As far as I know, your construction company is not allowed to issue a KfW confirmation for you, as this must come from an independent body (e.g., another energy consultant). At least that’s how it was for us, and the KfW support is also billed completely separately.

yes that's true, the construction company has an energy consultant who does that. But he can't because he is still missing data that the construction company would have to provide him... so instead of building, I am waiting....

To my knowledge, your construction company is not allowed to issue a KfW confirmation for you, as this must come from an independent body (e.g. another energy consultant).

It's different in our case!
KfW confirmation from the "in-house" energy consultant, who must be certified/approved (or whatever) as such.

As far as I know, your construction company is not allowed to issue you a KfW confirmation,

That would of course be the simplest explanation for why it could take even beyond next year's Sankt Nimmerleinstag until they comment on it :-(

I don't want to start a new thread and this fits best here: Does anyone know how long the building authority has to keep old building permits or the building file? I assumed that due to the 'lifespan' of houses it would have to be quite a long period, but now I have been told that the building file from 1955 no longer exists, it is too old...

The building file from 1955 no longer exists, it is too old...

Well, objections due to procedural errors in the approval process would probably be time-barred by now.