ᐅ Setback area between two buildings

Hello,
I am currently planning a house and am very interested in the topic of setback distances between two buildings.

Building A (Blue):
New residential house
Exterior wall 36cm (14 inches); two full stories + pitched roof; no window on the ground floor in the green area

Building B (Orange):
Empty machinery hall; about 5m (16 feet) high; exterior wall about 30cm (12 inches) (cement block); 1 small window facing south (red marking);
Located directly on the property boundary
At the moment, I would say that the southern wall is not a fire wall.

I would like to know what distance I probably have to maintain to building B? Would it help me if the southern wall (building B) were made into a fire wall?

I am not expecting a 1000% legally correct answer (e.g., with exact legal references). The dimensions in the picture are also not completely accurate. Just your opinion is fine.

deb10er0 schrieb:

Empty machine hall; approximately 5m (16 feet) high;

And this was allowed ON the property boundary???

The two plots of land used to be one (owned by my in-laws). The southern plot was transferred to us (divided). The boundary was then established there. This means the machinery shed was already standing in that location beforehand.

Oh, so you also own Hall B. How about demolishing it if it’s empty?

The minimum distance can vary depending on the region. For two full stories plus a pitched roof, it will definitely be more than 3 meters (10 feet). I would just take the plan to the building department, and they can quickly tell you whether it is generally eligible for approval and what the setback requirements should be.

So, the hall is located on my parents-in-law’s property. It doesn’t belong to us. They wanted to keep it and continue using it (I think as storage space).

Definitely more than 3 meters (10 feet).

Building authority = district office?

Setback areas and firewalls are two different things. I would also recommend visiting the building authority or consulting an experienced architect who has contacts at the relevant authority.