Distance to our rented property for new construction on the plot

and you put 2 high-rise buildings on a plot where there used to be a small hut, and then also garages. The neighbors (maybe tenants) could get upset now. If the 3m are complied with, then that's just how it is.

I am a bit surprised why everyone dismisses this so easily. I interpret the photos differently. The garage (permitted boundary construction) in the front view is indeed from the OP. What looks like an extension (on the right) is the utility room of the adjacent building and is clearly connected to the building envelope of the new construction. No one can convince me that this is clearly outside the heated envelope. The extension could just as well be heated and then it would not be permitted as a boundary construction.

Since there are already 2 doors from front and back, I dare to doubt that there is another door leading into the interior of the house. Otherwise, a 3x3m room with 3 doors is hardly usable anymore. But who would want a utility room without access to the house? I rather think it is a high-quality carport extension and "utility room" was just interpreted by the OP.

and you put 2 high-rise buildings on a plot where previously a little hut stood, and then garages as well. The neighbors (maybe tenants) could now also get upset. If the 3m are adhered to, then that’s just how it is

I don’t mean this morally at all, I’m just going by the recognizable facts and what options the OP would have then. Personally, in the OP’s place, I would also greet politely and ask if I may plant on the wall. Actually, your post is whataboutism, but I’ll go along anyway. I’m only building one (high-rise) house. Because I’m nice, 4.50m from the boundary, not just 3m. I’m also not building a garage and the possibly eventually built carport will stand on the boundary with the new neighbor, the long-established ones are not affected by this. The previous owner sealed the entire area and let the boundary overgrow with conifers, which he also didn’t prune. Those were real trees, no longer a hedge. The neighbors are rather glad that we are here now and hopefully more proper. My house actually shades the next neighbor’s terrace a bit. The man is a little sad but realistic (it just happens), the woman is even glad because she can’t stand the sun that much. I think, furthermore, here the extension stands on the boundary and not 3m away.

Since there are already 2 doors from the front or from the back, I doubt that there is yet another door leading into the house interior. Otherwise, the room at 3x3m with 3 doors would no longer be usable. But who would want a utility room without access to the house? I rather think this is a high-quality carport extension and “utility room” was only interpreted in by the OP.

True, you’re right, I didn’t recognize the door from the front at first, because the bricks of the building are reflected in the glass. Yes, the extension really doesn’t make much sense as a utility room. But as a storage room it’s quite expensive.

As a storage room, it is quite expensive though.

Yes. But for the OP, it is clearly better to have a high-quality extension next to the terrace than to have a plank shed placed right in front of their face.

PS:
I also built a 9m long garage next to my neighbor's house. He is probably not thrilled either, having to look at a white wall from his kitchen.
But what can you do with narrow plots? We weren't allowed to build further forward because we had to maintain at least a 5 m distance from the street.

definitely better to have a high-quality extension next to the terrace than to have a wooden shed stuck right in front of your nose.

True, or like one of those reflecting aluminum monsters, as in another thread here recently.

The tenant is not the owner but a renter; that means he has no rights whatsoever to inspect the construction documents. And the owner apparently is not bothered by it, as he seems to be on very good terms with the new house owner. Maybe they even have a deal - which two neighboring owners are allowed to make.

As a renter, you stand no chance. Either swallow the bitter pill or look for another rental property.

The discussion about whether this is legal or not is pointless. It must bother the owner, and then the owner must take action. As described here, one can assume that this will not happen. And where there is no plaintiff, there is no judge.