Which heat pump? Ventilation system / Air-to-water heat pump

Then I congratulate you on 350m² of living space!

And again he is wrong - I already know that you are doing it deliberately now, but please stop with the talk.

KfW55 per se says very little.

Architecture, individual needs in room temperatures, basement, heated area, domestic hot water demand, that is simply ignored.

By the way, I calculated a KfW56 house... but what good is the value to you now if it doesn't fit your picture?

Is your house already built?

You will have an energy certificate, which shows your Ht value. This provides a pretty good reference for how well your house is insulated (and from this, the heating load can also be calculated). Adding the number of occupants, it is also possible to estimate the energy required for heating domestic hot water quite accurately.

That is a factor of the heating load calculation - but what are you trying to tell me now?

I know how it works and what I have... by the way, you did not have those factors and immediately come to such conclusions.

Hot water is, by the way, something individual - I trust what we consume and not what a standard wants to impose on me.

And also a value that says something about the quality of your "shell / insulation" - so bring it on if your insulation is supposedly that good. Otherwise, I stick to my point - for a properly insulated house, a trench collector can be installed on almost any property.

My insulation exceeds the required (still valid today) standard and is now at 0.28. And no, you cannot reliably derive the heating load from that. Again: individual values change the heating load – I have assumed higher values for room and corridor temperatures than the standard.

You will probably throw your 0.21 at me now, but that only proves that the KfW statement says nothing.

I maintain that you should keep that blanket statement to yourself.