Neighbor wants to file an objection against construction

My question now would be whether this neighbor could actually take action against our construction due to any objections such as "construction noise" or "damage to access roads during construction," or if we are just worrying too much?

Only hard facts count: house does not comply with any distances, is 5m higher than the surrounding buildings, etc. So first, just relax.

We had the same situation, the neighbor used "our" future property free of charge for years and pulled out all the stops to prevent our construction. We didn't even find out beforehand and the building authority rejected all objections because we complied with all building regulations. As has been suggested several times, I would also talk to the neighbor and otherwise wait.

How old is the [Bauvoranfrage]?

How old is the preliminary building inquiry?

The preliminary building inquiry expires in March next year.

Thank you very much for the many comments in such a short time. At least that makes us a bit more relaxed. :)

The thing is, so far we have only heard about all objections through others from the village. They themselves haven’t spoken a word with us except for a "hello" on the street. Everything is just happening behind our backs and that is really annoying. Especially since we haven’t "done anything" to these people ourselves and just wanted to move into a nice neighborhood. Well, you can’t have everything. So we’ll wait and hope that the building permit arrives this month.

At the end of last month, some neighbors apparently received a letter from the building authority regarding "neighbor participation."
They are supposed to submit objections in writing within 4 weeks or not respond, thereby virtually giving their consent.

This is a completely normal procedure. As long as no legal aspects are violated (setback areas, floor area ratio, plot ratio, etc.), the building authority may not reject objections such as "I don't like it" or "it takes away my sunlight."
To speed up this process, we once went with the plans to 7 neighbors (yes, there is a path on one side that belongs to the community property of terraced houses) and had the plans signed. Fortunately, one of the neighbors was an architect and explained to the others that the plans comply with all legal requirements and that nothing can be prevented, only delayed by a few weeks. This usually spoils the mood right away, which nobody wants. So in the end, everyone actually signed ;) .

this is also something in Germany, the secrecy. When you submit a building application in the UK, which has been done online for ages, the building authority reviews the application within 5 days for formal errors or missing documents. If it takes longer, you receive an email. This process is then visible online to the whole world. If the formal application is okay, the application is registered, the name of the contact person is communicated, and how long it will approximately take until the decision. There are time guidelines for this, usually 8 weeks. This is also the point when all direct neighbors are written to; they have 21 days to express their "displeasure." But anyone, not just a direct neighbor, can object or write something positive. These objections are also visible online to everyone; no one goes to any neighbor. The building authority reviews the objection (mostly it concerns privacy, shadowing, or the size of the building) and not a 10cm distance. This avoids communication between neighbors, which often is based on false assumptions, and the decision is made by a neutral person, namely the authority. I think this is all much better than the "amateurish" negotiating between neighbors, who in any case do not decide on the building application.

Since I am interested in a certain area, respectively the house plans, I receive emails when a new application has been submitted.