Distance to our rented property for new construction on the plot

If it no longer fits, move out. That is the advantage of the tenant. Urban infill after all

really? many would be glad to be able to live like that.... that's complaining at a high level.... but to stay factual: the rental contract describes the rented property, the size of the garden, etc... this has not changed since a boundary development took place. contractually, there is certainly no assurance that the neighboring property belongs to the rented property or remains free... ergo no breach of contract by your landlord. you also only live there for 4 years and would prefer the new neighbor to have the house torn down so you have sun again? if you no longer like the rented property, a change would be the best option....

Fun fact: Your terrace is too close to the border, not the neighbor's garage.

Maybe it is actually bigger in reality than in the permit.

But as a property owner, that would bother me... How can the neighbor even sit on the terrace in that spot. Immediately apply to the building authority for reconstruction/reduction. ;)

If it helps: In case of doubt, I prefer such a beautiful wall on the border to the terrace, windows, door, etc. of my neighbor 3 meters away.

A few bushes where it is open and it’s closed.

I am a bit surprised why everyone dismisses this so easily. I interpret the photos differently. The garage (permitted boundary development) in the front view is indeed from the original owner (TE). What looks like an extension (on the right) is the utility room of the adjoining property and is clearly connected to the building envelope of the new building. No one can tell me that this is clearly outside the heated envelope. The extension could just as well be heated, and then it would not be allowed as a boundary building. How to find out this beyond doubt without upsetting anyone, I currently don't have advice on. Maybe ask if one could use the washing machines once, as one's own is broken and the service only comes later...? That would be a bit cheeky, but if the pressure is that high...

clearly connected to the building envelope of the new building. No one can tell me that this is clearly outside the heated envelope.

But you can only assume that.

How to find that out beyond doubt without offending anyone, I don't know how to advise right now.

Step 1: Check construction documents so you know what was built Step 2: Talk to the neighbors. When moving in, you do that at the latest - a "Welcome to the neighborhood." And every homeowner is proud to show their new house to the neighbors.