KfW - construction: is it necessary or not?

I actually agree with you there. If it’s only about ecology, then it’s all nonsense, because buying a used house is the most ecological option.

Yes, the only problem is that it is still about a new build.

um.....WHERE does it say that? I don’t read that from anyone; neither from proponents nor from opponents. Exactly THAT is what most people here were about, that it is NOT black and white, as you apparently perceived it. Your slightly aggressive response surprises me a bit, and the words "violence" and "nonsense" come exclusively from you. It was mostly about differentiation, from what I read. Having a different opinion doesn’t mean that your project or your attitude is nonsense. I share the ecological mindset but am critical (a difference from grumpy) and do learn something from the discussion. I don’t believe anyone here wants to spoil your project just because they allow themselves to have a different or more nuanced opinion.

Where do you get from me that it’s black and white? I’m really interested in that now. Especially because I have repeatedly said that this is my very own priority and nooooo one else has to share it. I don’t have the feeling that anyone wants to spoil my project. I much more have the feeling that people want to prove to me that an "eco house" (please note the quotation marks) is basically no more ecological than an Energy Saving Ordinance house. And that, with all due respect, I still consider wrong. "Violence" and "nonsense" are, by the way, not really harsh words that would require attributing aggressiveness to me. Especially not in the above context. Building and letting build, that’s where I’ll leave it then.

And who is actually acting missionarily here?

Well, so far you are the only one who has spoken about "nonsense," "stupidity," "rubbish," and "violence." Also, the stereotyping and black-and-white thinking that you display is suspicious. Likewise, that you shy away from the content of the discussion and immediately drift into the aforementioned rhetoric.

I rather have the feeling that someone desperately wants to prove to me that an "eco-house" (please note the quotation marks) is basically not more ecological than an energy saving ordinance house.

Please provide the corresponding quote, I don't see that anywhere.

... who get their electricity during the heating period from fossil fuels? Or from the nuclear power plant? The photovoltaic system does not help in winter.

Then the heat pump is ecological?

... which also have to be produced and later disposed of again (see all the Styrofoam waste that has been/ is still being produced for a long time).

Assuming you build your house with a heat pump and use 100% green electricity.

Since only a limited amount of this electricity is available, electricity must be generated with coal or gas to compensate for your consumption.

This can lead to the fact that it would be more ecological to produce little CO2 with an efficient condensing boiler, instead of making electricity with "a lot" of CO2 in a coal power plant.

Green electricity always also includes bioenergy. Then wood and other plants are simply burned. They just grow back.

Ever looked at how much embodied energy is in such an EPS-KfW55 little house? You can hardly burn that much over the usage period of an ordinary Energy Saving Ordinance house.

That you all are so sensitive today – as if my last post had been so aggressive... I think you can also clearly read that it was of course intentionally written polemically. So guys, a bit more thick skin please.

By the way, enough has been discussed in terms of content – of course we can now also talk about whether biogas plants are so great, but we won’t come to an agreement there anyway.

The OP is building and wants to know if KfW55 is absolutely necessary. For what feels like the tenth time: No, it does not have to be. Does it make monetary sense? I don’t know. Is it a benefit to me aside from monetary considerations? Yes, definitely.

But it’s not about me here either, I just wrote down my thoughts on it. I’ll leave it at that.

The OP is building and wants to know if KfW55 is absolutely necessary. For what feels like the tenth time: No, it obviously doesn't have to be.

Agreed! But with regard to energy consumption and/or resale value, it is advisable to build as energetically "modern" as possible, as long as it is financially justifiable. And that is something everyone has to decide for themselves.

So guys, a bit more thick skin please.

Can you demand "thick-skinnedness" when you respond to a factual discussion with "polemics"? I don't know...

Back to the original question
KfW house basically means nothing other than your house must meet certain requirements of the KfW to receive funding.

So check the KfW pages to see what the current funding options are.

KFW often also means a heat pump as heating, for which there is also funding this time from the BAFA. So also check their pages to see what funding you can get.

Once you have this data, you can calculate yourself whether KFW 55 is worthwhile for you.

You only have to comply with the Energy Saving Ordinance.