Which heating system should one choose for a new building?

Reference electricity probably won't get cheaper... Father State always comes up with something. And what do you want to do with the money in the account? There are more pointless expenses than a photovoltaic system. Financially, a fireplace isn't worth it either, right?

And what do you want to do with the money in the account?

I don't know a single home builder who has done it without a loan. On the one hand, that's because I don't know the right people, but also because many people don't have that much lying around in their account. That means that for new builds (which is what *this* forum is about), presumably 99% of photovoltaic systems are financed with loans.

And whoever has the money in the account just spends it on something that yields more (returns or fun, depending on taste).

Well, do really 99 % of people finance their photovoltaic systems externally? That surely costs 2% p.a. in interest, plus processing fees, etc.? That really wouldn’t make sense; a photovoltaic system might produce a small profit over its entire lifetime—especially since no one knows the electricity price in 5 or 15 years—but with financing costs?? Well... most people probably aren’t like that. Why would anyone borrow money at interest for a system if, after fully repaying the loan, it turned out to be a clear loss? You might as well not do it at all. But hey, to each their own...

Apart from the fact that a rooftop photovoltaic system can be financed not only through KFW loans but also as part of regular construction financing (so under 2%), something like this doesn't cost the world. The maximum in the house class (so just under 10kWp) was available two years ago for 13,000 euros. It's not like it's free (see above) but also not unaffordable. My system costs me about 8 euros/month in interest. So roughly 1 1/3 packs of cigarettes.

Well, do really 99 % of people finance their photovoltaic systems externally?

The figure was of course polemical and referred to the context of this(!) forum, where home builders discuss. The farmer who covers his barn or stable, which has been debt-free family property for generations, or the owner of a debt-free home usually certainly pays for the photovoltaic system from savings. But those who build a house new usually(!) do so on credit. At least I do not know any other case, and the prevalence of the topic "financing" in this forum suggests this conclusion. And then, regardless of the equity share, I claim the photovoltaic system is always financed by credit. Because those who omit it must immediately take out a loan reduced by the acquisition costs.

I built my third house and numbers don’t lie The most important thing is the insulation, with my passive house standard I don’t have 400€ a year in energy costs and that with a very cheap heating system in terms of acquisition cost and I don’t have to go grocery shopping wearing a jacket and wool socks I just have a good comparison to my other houses but to each their own, there are also people who are willing to pay more for [Ökostrom] which is also okay