Funding outside of KFW - What still makes sense now?

Yes, difficult decision. We would only have the photovoltaic system pre-installed for 500€. Then build the hut first. Saving the thicker stones, but still with controlled residential ventilation (because I consider it sensible, cost point 18K€). I don't think it pays off with the subsidy because then the energy consultant with 7500€ comes on top for all the hassle with KFW. I can then retrofit the photovoltaic system a year later and use an existing building renovation subsidy for it, which surely must also come. Or am I missing something?

You want to install a photovoltaic system on a then 1-year-old building as a refurbishment? ^^

There is no renovation subsidy for photovoltaics anyway, only the feed-in tariff. And here in BW the photovoltaic obligation, in other federal states it will also come soon.

I can then retrofit the photovoltaics a year later and use an existing building renovation subsidy for it, which surely must also come.

There is even one for new buildings already. It's called feed-in tariff ;)

There is no renovation subsidy for photovoltaics anyway, there is only the feed-in tariff. And here in BW the photovoltaic obligation, in other federal states it will also come soon.

I don't know if I would be happy with that currently.... Everything already costs an incredible amount in house construction anyway... Obligation within 3-5 years after completion is fine... but here some pressure could be taken off the builder...

You will never be able to install a photovoltaic system as easily as during the construction phase. Scaffolding, crane, electrician are all there, you can immediately cover tiles with the brackets in the right place...