Floor plan conversion of part of a barn into a single-family house with the option for a two-family house

Unfortunately, I cannot post photos of the current situation because my partner does not want them on the internet for privacy reasons, also considering the renovation with the "secret" goal of later repurposing. Please excuse that. [...] - here is the floor plan so far [...]

More likely the planned floor plan, although I always emphasize the importance of comparing the existing situation and the plan. Regarding the reason, I can only say "joker": it's obviously a joke that the internet is allowed to know where your bed and your toilet will be in the future - but not, oh my, highly confidential which little wall will be nibbled on and which window will be newly broken out. We certainly didn’t want to see the demolition work with your dear husband naked on the Hilti.

What does suitable condition mean? As soon as you tackle the roof and replace more than just a few rafters, it is no longer a repair and requires a building permit. As soon as you work on load-bearing beams, walls, a building permit is required. If it is only a few wall infills that are being renewed, then the building authority does not care and you will not be forced to tear down the barn because of it. An expansion permit does not depend on the condition of the barn. That is your private pleasure if you want to sink money. Strange advice from the architect.

As mentioned, I will not go into more detail about building permit aspects here, as I apparently cannot explain the situation clearly. We will follow the advice of our architect, who has successfully managed countless building permits in rural areas within this region and therefore has a lot of experience. We are also aware that the building authority cannot demand that we demolish the barn; however, they can deny us a change of use, since according to §35 Abs. 4 Nr. 1. a., the project must serve a practical use of valuable existing building fabric. And at the moment, we simply do not have this, but we are working on preserving it through renovation. And therefore the request to discuss the floor plan. Sorry if these answers do not satisfy the building law expert’s heart.

since I apparently cannot explain the situation here understandably.

But now at least yes. Fifth word