Construction financing - How will it change in the future?

All of this is also unsettling me right now, we are about to sign with a house builder... KFW 40 would thus be available to us as a subsidy. No one knows how it will develop, will the conditions get better - worse? I have to talk to various financiers this or next week. I currently have concerns about signing now and regretting it afterwards. But unfortunately, you never know...?!

for KfW, companies are the focus and not the homeowners

Everything is still very much in flux – but the idea of new home construction subsidy programs like Baukindergeld Plus is, in my opinion, rather far-fetched. All those x-hundreds of billions of euros in aid have to be financed. As the MP BW recently said: "Most people will be poorer after the Corona crisis." Instead of a dip, we initially had the V, now more likely a U – and the World Bank & IMF see the crisis as even bigger worldwide.
Therefore, new sources of money are more likely to be sought in the future, and perhaps real estate owners will come into play again.

Therefore, one should look as poor as possible..especially with real estate, the land registers nicely full of debts for the state. But the demand for housing remains high. In the Cologne area, nothing has changed currently regarding renting.

and the prices will drop by 10% to 25%.

As stupid as this is for you, most people here won't care at all since they are mostly building their first own house and come from rental apartments. As long as the banks don't come back to me afterward with anything regarding the changed loan valuation, I don't care how much the house is worth.

I am building it for my family and not to sell.

If the old house becomes cheaper, this should also be noticeable (with a time delay) in the new building. The only stupid thing is to build expensive and sell cheap. As always in life. But you can't know that beforehand.

I would just go ahead with my project now. For the old house, you take out a bridging loan. The problem with the idea of selling first, then building, is that you need a buyer who, for example, wants to wait 12 months before moving in, and you put a gun to your own head to definitely finish within the time frame. It only causes stress, for example, motivating you to accept an offer that is (supposedly) executed within your deadline, etc.

As long as the banks don't come back to me afterwards with anything due to the changed lending,...

That's exactly the problem. If this case occurs, I see them dropping like flies, the many people with their tight 100-120% financings. In their place, I wouldn't have a moment of peace right now. Then it would really be about existence. No one will get away with just a scratch. So IF it comes to that, it will be really bitter.