Terrace roofing for a semi-detached house

I wonder, and I haven’t found anything about this online, why the neighbor can oppose it at all? After all, the canopy is on our property. How is it supposed to be possible to maintain a 3m distance to the neighbor in a semi-detached house?

So first of all, you read in the building regulations of NRW. If you do that, you find under §62 that terrace canopies are exempt from approval, provided they are small and the distance to the neighbor is 3m. Then you realize that you cannot maintain the 3m distance. Therefore, you continue reading in the building regulations and find under §67 that you can submit the building application yourself. Perhaps boundary construction according to the development plan and floor area ratio is still possible and the neighbor does not have to agree? Or it might require an attached building burden or a similar private contract? So it's not quite simple. In general, the city is right both with the statement "you can just do it like that" and with "a building permit is required." It depends on how each of you inquired. My tip: Get the development plan online. Check what is possible. Go – not call, but go in person with the documents – to the building authority and talk to the caseworker so that he can assess the specific situation with the development plan, existing building, and planned canopy. If you want it more specific, then submit a free preliminary building inquiry. It takes 20 minutes and you get a legally secure statement.

That may sound very pedantic, but that’s how authorities think:
Does the authority say that you need a building permit in order to be allowed to build? Or do you have to submit a building application so that the city confirms through the building permit that you are allowed to build.

It may well be that you are allowed to build, but the city does not want or is not allowed to give you legally binding information about it without receiving money for it in the context of a building application.

It’s incomprehensible.
The neighbor never uses his terrace! Never!
And he can decide whether we get one or not?! It’s my garden after all. I just don’t get it.

You don’t understand it.
The neighbor never uses his terrace! Never!
And he can decide whether we get one or not?! It’s my garden after all. I just don’t get it.

Like you, the neighbor also has rights, for example how he uses his garden. Just because you think he has forfeited his rights by not using it doesn’t mean you are right.

Because it will be associated with who knows how high costs and effort

Who knows how much… that can be inquired. Anyone who wants a terrace roof, which is not free, can probably also obtain a legally secure permit for 100/150€.
Where is the problem? Only in your perspective about your neighbor.

Like you, the neighbor also has rights, for example how he uses his garden. Just because you think he has forfeited his rights by not using it does not mean you are in the right.

Who knows how… one can inquire about that. Whoever wants a terrace roof, which is not free of charge, can probably also obtain a legally secure permit for 100/150€.
Where is the problem? Only in your perspective of your neighbor.

I expected higher costs.