Is a new construction possible with our cost estimates?

I strongly recommend a preliminary building inquiry. Friends of ours got badly burned because the verbal information from the authority was overruled by the higher authority. It was also about building in the second row and combining two parcels to have space for building. However, in NRW, grassland in the outer area cannot simply be used by merging parcels to increase the floor area ratio. Now they are allowed to seal a maximum of 80 sqm and are disputing with the building authority about the number of floors.

For a formal preliminary building inquiry, we already need all documents such as site plan, building plan and drainage, right?
So we would commission the general contractor without knowing if we actually have a property, correct?

By the way, the building authority shares that opinion and unfortunately, but understandably, only gives ideas and does not say anything directly.

Here is the answer from the building authority:

"For plot A alone, no further development is possible, as the plot is already developed with a large house and numerous outbuildings and thus the utilization seems to be exhausted at first glance.

Without combining the two parcels, plot B becomes outer area, which is reserved only for agriculture.
New buildings in outer areas are not permitted without this privilege.

If the parcels are combined, the structures of garden use can possibly be classified as inner area, because then there would be no separating boundary.
In the case of classification as inner area, §34 of the Building Code would have to be observed. Here you will find the 5 integration criteria.
A model would then be the rear development of plot C/2 house no. 14a with a rear distance measured perpendicular to the street of about 35m.
It is advisable to submit a preliminary building inquiry with the drawing and size of the desired house in a cadastral map."

How should one best proceed here?
As laypersons, we cannot simply convey the exact dimensions and desired location to the building authority and just ask.
Or should one turn to an architect here?

Best regards

Or do you contact an architect here?
Best regards

Exactly, an architect who is familiar with construction projects in outdoor areas is the right contact person here.

The building authority has clearly told you what you should do. Submit a preliminary building enquiry. You can do that on your own. You should be able to manage a scaled sketch of the property and house.

The exact dimensions and the desired location cannot simply be conveyed to the building authority and inquired about by us laymen.

Oh yes - in almost all federal states you can actually do that as a layman just like that.

You are great, thank you very much for the quick answers.

Can one already assume fictively in the preliminary building inquiry that our properties A and B already belong together, or must a merger have taken place beforehand?

When combining the plots, it may be possible to assign the structures used for gardening to the inner area,

O-o, it can be done, but does not have to be.

It is advisable to submit a preliminary building inquiry with the drawing and size of the desired house on a cadastral map"

That is an instruction, what they advise you.

As laypeople, we cannot simply provide the exact measurements and desired location to the building authority and ask.

Yes, you can, what do you see as a problem?