Is a central ventilation system absolutely necessary?

The topic is very emotionally charged If you ask 3 builders, you get 5 opinions.

Therefore, here is my opinion:
Not necessary. We build with humidity-controlled supply air elements (from aereco) and exhaust extraction in the bathroom (upstairs) and guest WC (ground floor). And no, in winter you will not be sitting in cold drafts with a scarf and jacket. Our architect has been installing these things for many years. So far, there have been no complaints from the residents. No mold either. The investment costs are much lower than with a controlled residential ventilation system with supply and exhaust pipes in all rooms. The running costs (heating the cold air with the described solution vs. electricity, maintenance, and filters in controlled residential ventilation) will probably balance out.

And no, in winter you will not sit with a scarf and jacket in cold draught.

Unfortunately yes... unless you are simply not sensitive to cold, consider 20 degrees in the house warm, or have enough money to keep the heating running constantly...

Hello,

Your architect has no clue...

On the contrary, the architect finally seems to be someone from real life!

we went to the energy consultant and he said that for our house (which will only be built starting spring next year) he would definitely recommend a central ventilation system (because of mold) our potential architect says that it is not necessarily needed, but ventilation in the bathroom and kitchen would be enough.....

For understanding: Your energy consultant recommends the central system because it will subsequently be easier for him to provide proof. Your architect is right because, in fact – if at all – heat recovery only pays off in the wet rooms and the kitchen.

Whether central or decentralized – opinions differ – I would always recommend you decide on one option if you cannot ensure multiple ventilation sessions within the first two years. And don’t let anyone convince you that you will be “drafty” if you choose a decentralized system. We have been installing this on and off for many years and since then no customer has suffered from constant runny noses or joint pain.

Rhenish regards

"Ist Zentralventilationssystem is not only expensive but also somewhat complicated to install and difficult to clean; over the years it will probably become very dirty and can also develop a musty smell."

So these statements from the architect are just nonsense.... provided it is supposed to be a house according to today's standards...

Hello,

"central ventilation system is not only expensive but also somewhat complicated to install and also difficult to clean, over the years it will probably become very dirty and can also get musty"

The architect would not have said that exactly like that, even if there is some truth in it.

So these statements from the architect are simply nonsense.... assuming it is supposed to be a house according to today's standards...

I have already told you several times – a central system seems to have been the exactly right choice for you. That neither means that it must be good for others, that a decentralized system is therefore worse, nor that a central system is free from susceptibility to faults.

You should go to construction sites once and see how some central systems are installed, what footprints you find on the plastic pipes, how quickly the screed spreads the mantle of silence, etc. then you will come quite quickly to reality. That a system can also "get musty" is also not far-fetched... in the first years the cleaning intervals are still maintained... then it declines until it is – not infrequently – completely abandoned.

Ultimately it is always also a matter of price; there is no better or worse. Only more or less comfort

Rhenish greetings

....For understanding: Your energy consultant recommends the central system because it will be easier for him to provide the proof afterwards....

The proof can be provided just as easily with a decentralized solution.

..., to decide on a variant if you cannot ensure repeated ventilation within the first two years....

For drying out a building, you do not have to install an expensive controlled residential ventilation system! Modern buildings are very well insulated, so the air changes per hour (ACH) are accordingly high. Therefore, mold hardly stands a chance here. Decentralized controlled residential ventilation can be described as "half-baked". Inefficient, often problems with noise levels and/or condensate. Whether you should definitely have such a thing in the bedroom is certainly something to consider.
Best regards.