Is the neighbor building legally and how do I find out?

Nana. Live for decades in a familiar environment and suddenly someone puts something right in front of your nose. A bit of understanding should be present that the residents have to more or less get used to it.

I'm sorry, but I have no understanding for that. Once again, the neighbor who, by his own description, is generous to everyone, peace-loving, and understanding, is looking for a preferably anonymous way to forbid the other his house construction approved by all public authorities, because otherwise he would have to change his "habits" acquired over decades. In most cases, the approval authorities are quite familiar with setback distances etc., so that when a building permit is granted, one can assume that it fits. Even if it doesn't fit and the neighbor has to move his house one meter forward or make it smaller, thereby gaining space for a nice garage directly on the boundary, what exactly has been gained? Live and let live is all I can say.

The garage of the new neighbor is completely outside the building window according to the development plan. Nothing has been built in this alignment throughout the entire street. I always thought that garages, like residential houses, had to be within these lines - was I wrong?

Yes, you are wrong. § 23 para. 5 of the Land Use Ordinance. Garages are not ancillary installations, but here they are probably buildings that may be permitted in distance areas. The whole matter is at the discretion of the authority (the term does not mean arbitrariness). However, development plans can also completely or partially prohibit such facilities, and then the authority is bound by them. See also BVerwG 4 B 27.10

I do not know if I understood the planning correctly. But a terrace is not allowed to be built by the neighbor within the area of the 3-meter distance zone. That would normally not be permitted.

I don't know if I understood the planning correctly. But a neighbor is not allowed to build a terrace within the 3-meter distance area. That would normally not be permitted.

I don't have time to verify that before the Easter weekend. So I'm asking you if you also have a source for that which is valid for NRW? In my opinion, that is wrong, at least according to the old building regulations, since terraces (as long as they are not covered) do not trigger any distance areas.

I don't have time to verify this before the Easter weekend. Therefore, I'm asking you if you have a source for this that is valid for NRW? In my opinion, this is incorrect, at least according to the old building regulations, as terraces (if not covered) do not trigger any setback areas.

You are right that terraces normally do not trigger setback areas. But according to § 4 Abs. 1 Neighborhood Act NRW, "architectural parts intended for access such as balconies and terraces may only be attached if a minimum distance of 2 m from the boundary is maintained." Of the 3-meter setback area, only one meter may be terrace and then two meters must be free.

Of the 3-meter setback area, only one meter may be terrace and then two meters must be free.

Maybe my question is a bit simplistic again, but how do you differentiate between terrace and non-terrace? Every paved area is "practically" a terrace, or am I seeing that wrong? For example, we still plan (of course only after I have discussed the outdoor area in detail with experienced forum members here in a dedicated thread ;-) ) to pave a little around the whole house. You could stand around the house everywhere with a coffee or a glass of sparkling wine. Does it then count as a terrace because of the surface (paving and not, for example, lawn)? Would any somewhat wider path directly around the house then be considered a terrace?