Which KFW standard and which technology in new construction

There is a lot of confusion here. Someone is advertising a building services forum, and I can already guess what is recommended there, you know that from hi-fi forums and such. There, the newest and best and most expensive is always the state of the art.

That’s one way to shut down a discussion. A multitude (!) of opinions that differ from one’s own are quickly classified as irrelevant because it’s all tech-obsessed nerds who have a distorted view of reality. Fair enough.

The DIN standards, the ventilation concepts. The fact is, a building completely without any forced ventilation is legal and is always accompanied by the builder with the note that regular ventilation is required! For example, we received a kind of manual for the house where this is clearly stated and described in case of opting out of forced ventilation, including a description of how to ventilate properly. This places the responsibility on the customer.

The fact is that this is unfortunately not entirely correct.
"In Germany, since then, proof must be provided as to whether sufficient moisture removal is ensured even without active window ventilation. If a ventilation concept is created, the occupant has a legal obligation to comply with it. If the architect or planner does not point out a missing ventilation concept or non-compliance with DIN 1946-6, he is liable in the case of mold damage.

[...]

This circumstance cannot be avoided by a corresponding clause in the general terms and conditions. In such a case, very detailed ventilation instructions would have to become a clear contractual component. And even then, according to legal experts, it is highly doubtful whether a violation of the generally accepted rules of technology does not occur. Whoever wants to be on the safe side plans in such a way that hygienic air exchange is guaranteed based on a realistically assessed ventilation behavior of the occupants. The ventilation concept provides approaches to solutions."
Source see above.

In summary: simply saying we build without [forced ventilation], you just have to ventilate twice daily is quite controversial, especially since moisture protection must occur independently of user behavior.

That some Haiopeis (general contractors, architects, building technicians...) do not stick to what they should do is nothing new in the construction sector. That this sloppy work would legitimize itself because it is often done, I find somewhat odd.

By the way, the standard does not say that a controlled residential ventilation system must be installed, only that the volume flow is sufficient – this can of course also be done via window frame vents. This is not mutually exclusive; whether one wants that is another question (I find it completely outdated and a false place to save money in new construction. But that is my subjective opinion.)

Yes, it does. Nowadays, you really have to search for tariffs without base fees to find anything cheaper.

Well, I pay 25 cents, and I have a base fee anyway.

And the more you consume, the less the kWh costs (because of the GG). So: turn on the heating element

So I pay 25 cents, I have a basic fee anyway.

Please divide your basic fee by your kWh (both per year) and add 0.25. Then share the result with us!

Checked it for you right away:
It's even only 23 cents. The additional base fee cost for 2000 kWh, which the heating requires, is 8 euros per year.
That then amounts to 23.4 cents.

This varies extremely regionally in Germany. For example, there is about a 5 cent price difference between NRW and Bavaria.