KFW40 or better in solid construction, possible without additional insulation?

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Biomass heating system or brine heat pump instead of air heat pump, possibly battery storage.

A domestic hot water circulation is then also not permitted...

Air-to-water heat pump or air heat pump is sufficient for passive house or KFW40.
Biomass heating system or brine heat pump is not necessary for KFW40 or passive house.

Domestic hot water circulation is possible - if one wants to have one.

Drinking hot water circulation works - if you want to have one

This would already have been detrimental to funding for Kwf55 according to our general contractor, back in 2017?

And it is always about the annual primary energy demand referenced to the reference building: If the nominal demand is set, then thanks to a higher annual performance factor with brine compared to air, you can calculate/beautify a lower annual primary energy demand. And presto, thanks only to the better annual performance factor, you have turned a 55 house into a 40 house, just because of more efficient technology. Not because the house "naturally" has a lower heating load.

Yes, the expert will still be involved. And I also don’t know how it looks regarding personal contribution, whether something might get in my way there, because I want to do as much as possible myself. But that is all still too far ahead. And you are absolutely right. The topic is complex


Because, to my current knowledge, the solid wood house will be considerably more expensive.

:
Drinking water circulation is out of the question anyway. In my opinion, it’s complete nonsense in a single-family house. I didn’t do it during the renovation of our two-family house either. You can wait 5-10 seconds

Is an air heat pump really not allowed for KFW40?
Ok, I’m leaning towards a ground-source heat pump anyway. But that topic is still much too far away and I haven’t dealt much with what is more sensible.

Information sheet KfW "Annex to the Information sheet Energy-efficient Building"

The requirements for a KfW Efficiency House 55 are met if the following structural and technical system requirements (reference values) are implemented. In this case, a calculated proof for the KfW Efficiency House 55 is not required. ,,,

For the technical system, one of the six following system concepts must be implemented. The installation location of the heat generator or the heat transfer station must be within the thermal building envelope and a central domestic hot water preparation must be present. A domestic hot water circulation is permissible.

 Condensing boiler, solar domestic hot water preparation (standard values according to DIN V 4701-10), central ventilation system with heat recovery (heat supply rate ≥ 80 %)

 District heating with certified primary energy factor fp ≤ 0.7, central ventilation system with heat recovery (heat supply rate ≥ 80 %)

 Central biomass heating system based on wood pellets, wood chips or logs, central exhaust air system

 Brine-water heat pump with surface heating system for heat transfer, central exhaust air system
 Water-water heat pump with surface heating system for heat transfer, central exhaust air system

 Air-water heat pump with surface heating system for heat transfer, central ventilation system with heat recovery (heat supply rate ≥ 80 %)

We had one in the calculation and it was not harmful. 2017 Kfw 40. Passive house is not better subsidized. However, we did not install any.

With a suitable building envelope, you don't need technology to achieve KFW 40 or a passive house. KFW 40+ is only possible with [die wird auch extra gefördert].

Ok.
But that’s not really the point here. My main concern right now is a good insulation of the building envelope and how to achieve this sensibly, or which variations there are.

Whether I then officially classify it as Passive House, KFW40, or KFW50, I can still decide later once all criteria are considered.

What’s certain is that there will be a heat pump or a log wood boiler, with a strong tendency towards the heat pump.
There will be controlled residential ventilation.
There will most likely be photovoltaics installed on the roof.

That’s all pretty much fixed.
Right now it’s really about: solid construction or timber frame.

But with the desired very good insulation, timber frame seems to have a price advantage.
Now I just have to see whether the lower price also compensates for the disadvantages.

Thanks already for the lively participation!
At least I now know that pure solid construction without additional insulation is probably not sensible given my expectations for insulation effectiveness.

Regards
Specki