After reviewing the development plan - Are soundproofing measures necessary?

EV40 house in timber frame construction. We deliberately chose window case ventilation.

That works? Someone is calculating that very creatively.

as a decentralized ventilation system.

Not one. That's half a dozen devices. For each device a 150-180 mm pipe in the wall. You don't want that. It definitely gets really loud in the house.

Not just one. That's half a dozen devices. For each device, a 150-180 mm pipe in the wall. You don’t want that. It definitely gets really loud in the house.

And already the quiet, barely audible rustling of the central ventilation systems in the show houses made me feel uncomfortable.
Why, no idea.
The fairly loud pump of the cat fountain doesn’t bother me or other noises.
But that does?
I don’t quite understand it myself.
My wife simply found the air inlet and outlets ugly, and she likes to ventilate.

And the barely audible whispering of the central ventilation systems in the show houses already made me feel uneasy.

That is because people are more attuned to familiar sounds than to unfamiliar ones - especially in an unfamiliar environment. That creates skepticism.

My wife simply found the air inlets and outlets ugly and she likes to ventilate.

They are certainly not pretty, but that also applies to power outlets ;). And why don’t people consider power outlets worth mentioning? See above. And if you look closely, power outlets are even uglier than the homogeneous outlets of controlled residential ventilation. Many like to ventilate and have fresh air. That changes abruptly when you HAVE TO do it, about three times a day, even in sub-zero temperatures - every room. But of course, you can also ventilate with a ventilation system :)

GU suggests a decentralized ventilation system.
In my opinion, I think a central one would be better.

Yes,

If no ventilation was planned at the beginning and now the choice is between central and decentralized, here is 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 offer good programmability to automatically counteract heat in summer.)
Therefore, if the budget allows, I would plan with a central ventilation system.

I see it the same way. The key regarding the budget will lie here, which is why the GU suggests this variant: namely fear that the customer will find the offer too expensive and might possibly turn to a competitor.

However, I noticed that I presented it a bit incorrectly. For that, I apologize once again from the heart.

That is long forgiven. And my "translation" shows that it was certainly understood. After all, it is no rarity that a newbie enters the room and speaks in a layman’s way. Therefore, we are already familiar with Risalite being called bay windows or Zwerchhäuser being referred to as dormers. Or that someone leaves out the quotation marks at the fake "site manager."

I am somewhat surprised that you write this to me.
Until now, I have not even found anything where it was written that a central ventilation system is cheaper than a decentralized ventilation system.

The decentralized variant is only noticeably more expensive if you think along and can calculate; it is apparently offered as “cheaper” than the central one. Or also due to reasons of (in)competence (as with the provider Kern-Haus). With a central controlled residential ventilation system, even a layperson notices if the entire house is not supplied with it. However, if you install inefficient small units scattered in part of the house and "decentralized" (which in this sense is synonymous with "not networked"), the offer may easily appear as a cheaper variant. If you correct the calculation trick and supply the entire house with small units, the disadvantage of non-networking (= lack of exchange / capacity pooling) remains, but the apparent cost advantage in terms of purchase price reverses (half a dozen times twenty percent is more than index 100). The operating effort adds to the inefficiency (due to the missing connection to a system) and the reduced performance (missing heat recovery and the like). Therefore, the decentralized version is rather suitable as a retrofit if you want to install a controlled residential ventilation system in an existing building and are content with ventilation comfort and better sleeping air.

the underperformance

… is negligible in decentralized devices. They basically all have heat recovery.

The decentralized variant is only noticeably more expensive if you think along and can do the math; apparently, it is offered as "cheaper" than the centralized one. Or also for reasons of (in)competence (as with the provider ). With a centralized controlled residential ventilation system, even a layperson notices if the whole house is not supplied with it. However, if you build inefficient small units scattered over parts of the house and "decentralized" (which in this sense is synonymous with "not networked"), the offer easily appears to be a cheaper variant. If you correct the calculation trick and supply the entire house with small units, then although the disadvantage of non-networking (= the lack of exchange / capacity pooling) remains, the apparent cost advantage in the purchase price reverses (half a dozen times twenty percent is more than index 100). In terms of operating effort, the inefficiency (due to the lack of connection to a system) and the reduced performance (missing heat recovery and the like) are added. Therefore, the decentralized version is rather suitable as a retrofit if you want to install a controlled residential ventilation system in an existing building and content yourself with ventilation comfort and better sleeping air.

I understand what you mean. I agree with you. Spending more money can have added value.

Right now, I’m just relieved that I have the buffer. I used to laugh about why my financial advisor put a buffer on top of the calculated buffer. We’ll get it done cheaper. After all, we are not that demanding.....

Now it feels a little different.