Property value in financing - How is it calculated?

Yes, but as I said, there are boom regions and rural * no one wants to go there regions * it may be that the bank only assumes 15-20

Depends on the size ;) 2000m² should help quite a bit, I think.

Building land is usually calculated with 600-800sqm, the rest is garden. The property is then not worth much. And in a rural area on top of that... Who likes to buy or build there? What is the demand like? I have often seen houses that were built expensively in the middle of nowhere and then later sold cheaply - keyword enthusiasts.

It is "dangerous" but our architect is working on sorting everything out.

Outdoor areas are generally more of a no-go for many banks.

Depends on the size ;) 2000m² should definitely help a lot, I think.

Yes; just comfortably 1200sqm not at building land price.