After reviewing the development plan - Are soundproofing measures necessary?

Actually, the main contractor is not to blame for this. I looked at the development plan again and probably completely misinterpreted or overlooked this point myself. You can call it my own stupidity if you want. Originally, window rebate ventilation was planned. That was also the standard. We decided on this fully aware. We wanted it that way. Development plan Gemeinde Etzelwang residential area Feil Don't be surprised, we are the first.

Of course, a house model in the catalog can only comply with the general building regulations, and not also with those of the development plan (which are not all the same even within one town). If your chosen house model goes beyond a standard (for example in the energy standard EH40 beyond the Building Energy Act), this does not necessarily mean that it is also equipped to a higher class in other respects.

We deliberately chose a window rebate ventilation. [...] In these adjustment measures, the decentralized ventilation system is listed.

The general contractor (GU) has thus translated the further requirements into necessary measures and taken your aversion to window rebate ventilation into account, concluding that offering a controlled residential ventilation is probably suitable. Such a system is central (if you want to include many or all rooms) and actually cheaper, but also more complex in terms of construction. This is probably how he arrived at his suggestion to offer you a decentralized version.

However, I want to get a corresponding picture before the construction meeting or the sampling and see whether this is a good solution or whether a central system is worth a certain extra cost, as I generally don’t see decentralized ventilation as particularly great.

I have already classified the two variants for you earlier. Value and price are "two different things," so the GU will offer you the central variant at a higher surcharge even though it is actually cheaper.

I am myself an independent building consultant, but currently fully booked well in advance and also neutral regarding construction methods. If you want to build with timber frame construction, I therefore recommend a consultant focused on that, for example Tobias Beuler ("Prefabricated House Expert"), Guido Freyermuth ("Prefabricated House Guido") or (warning, requires fluent Bavarian listening comprehension!) Andreas Zink ("Zink-prefabricated house").

I always correct my wife to "GU" or "construction company" when she says developer... she doesn’t like that either...

I have accepted this vagueness as a feature of lay language and don’t have to schoolmaster it every time. At least the original poster understood that even a timber frame panel house manufacturer is a GU.

Okay. Building development plan read. I do not understand the problem now.

Quote building development plan, emphasis by me:

To comply with the acoustic requirements in the noise-sensitive rooms of planned residential buildings, passive noise protection measures on the building (soundproof windows, decentralized or centralized ventilation systems) must be implemented in accordance with the requirements of the version of DIN 4109-1 valid at the time of the building permit. Proof must be provided in the building permit process.

Therefore, the question again, so that I can understand the problem:
Which ventilation system was planned?
Which ventilation system does the general contractor propose?
Which ventilation system is alternatively desired?

As far as I can tell from the building development plan, there is already a very wide scope here. The only thing that would not be allowed is to build without ventilation. However, as far as I understood the initial post, that was not planned?

Correct.
It was not planned to build with a corresponding ventilation system.
Due to the development plan, we are forced to install a ventilation system.
The general contractor suggests a decentralized ventilation system.
In my opinion, I think a central one would be better.
That is why I am bringing up this topic here now.

However, I noticed that I presented this somewhat incorrectly. For that, I sincerely apologize again.

I have already categorized the two variants for you earlier. Value and price are "two different things," so the general contractor will offer you the central variant at a higher surcharge even if it is actually cheaper.

I am somewhat surprised that they write that to me.
So far, I have not found anything where it was stated that a central ventilation system is cheaper than a decentralized ventilation system.

Okay. Now I understand!

At the beginning, I misunderstood:

The upgrade of the house includes a decentralized ventilation system, special soundproof windows, soundproof insulation of the roller shutter boxes, and a soundproofing expert.

Of course with additional costs.
But I am not very satisfied with the decentralized ventilation system and consider a central ventilation system to be better.

I therefore thought that initially a central system was planned and the general contractor now wanted a decentralized one.

Okay. If initially no ventilation was planned and now the choice is between central and decentralized, then my opinion on the question:
A good central ventilation system has a few features that a decentralized one does not have to the same extent. (Heat recovery in winter; pleasant humidity in winter thanks to an enthalpy exchanger. At the same time, some ventilation systems also have good programmability to automatically combat heat in summer.)
Therefore, if the budget allows, I would plan with a central ventilation system.

PS: Here we only have words. No facial expressions, tone, body language. Words make up less than 10% of normal communication. Therefore, it’s not a problem if there are misunderstandings. They belong to communication without facial expressions, tone, and body language. That’s why I ask for clarification, and that’s that. (Please imagine a smiling emoji here.)

... the smiling smileys are working again ;) :cool: