We have already tried to effect a change there with legal counsel. No chance.
Why and what should one want to achieve if the development plan, apart from the fact that it is a weekend property according to Par10 NVO, actually allows many or common possibilities?
As a municipality, I wouldn't want to change anything either, since 0.1 for an oversized property should be sufficient. Besides, they just don't want to clutter this edge section with oversized houses.
All statements we received in the context of the building pre-application excluded a roof extension.
According to the development plan, a full storey is allowed. If you plan a roof, then you can also expand it. Building authorities are not interested in so-called "half storeys" because they do not exist legally. So they cannot prohibit or forbid them.
Since you are rather sparse in communication here and also do not communicate concretely (a floor area ratio of 0.1 is turned into 117 sqm of floor area), one must honestly assume that you may have asked the questions incorrectly at the office and thus are misinterpreting the answers for yourself.
On the one hand, you confirm the 2500 sqm, accepted by . Floor area ratio of 0.1 and your floor area assumption, however, point to a 1170 sqm property.
Then it is a SW property, i.e., weekend property, which you ignore. Why anyone would pursue such a property that apparently no one else wants, you cannot be asked.
The access is questionable. In the end, you showed a larger section where one can read something about a private road. Have fun with the access!
When asked where the property is, you say something about Bielefeld. But Bielefeld is not in Lower Saxony.
Are you afraid that someone here might buy your bargain property from you? I think no one here is interested in taking away a weekend property from a user who just asks one or two questions here.
Have you ever thought about why the property still hasn't been sold?
There are no conditions there and the building pre-application for the bungalow has already been approved.
The development plan is very one-sided. No converted attic and max. 117 m2 building area.
As already mentioned: none of that is stated there. It says: one full storey (mandatory). If that means that a roof definitely may not be converted, then a basement would also not be legitimate.
So, basically, hardly anything about the development plan that regulates the area here is correct.
Why even submit a pre-application for a "bungalow" if a single-storey building is allowed? There is no such thing as a bungalow legally (purely an interpretation by builders and construction companies).
Why start planning without even having calculated the house price based on the living area? Without questioning the access? It is no secret that building is expensive?!
If you want to present and discuss a (new) house design, then this would be the right subforum:
https://www.hausbau-forum.de/forums/grundrissplanung-grundstuecksplanung.237/