Financing for construction projects in autumn

I rather see interest rates rising. The Fed has announced an increase, the Kfw subsidies have been stopped. Everything else is just speculation.

Are you talking about inflation or loan interest rates here?

Inflation is decreasing slightly, interest rates will continue to rise. The beginning has already been announced in the USA (four hikes possible this year), Lagarde has also not ruled it out. Bond purchases are declining.
The era of (extremely) cheap money is over. In addition, measures that are already being implemented now are making loans more expensive as well - increasing equity/capital reserves for loans.

==> it can no longer get cheaper with the measures already implemented or the outlook for the future.

Although all the complaining is at an extremely high level. Only those who have to calculate very tight will find it difficult.

P.S. By the way, rising inflation is traditionally fought with rising interest rates. What happens when one acts differently can be clearly seen in Turkey.

Kfw subsidies have been stopped.

They will come back, that is also planned.

...
The era of (extremely) cheap money is over. In addition, measures are already being implemented – increasing equity/reserves for loans, which also makes them more expensive.
...

What exactly does that mean? Do banks now want more equity, and will 100% financing become extinct?

The banks should secure themselves in case the properties are worth less in a few years than they are today. This can be achieved through higher equity and higher repayment. For this purpose, the banks themselves should also save a reserve, which of course must first be earned through higher interest rates. And theoretically, the bank should also check more critically how the follow-up financing will look if interest rates rise significantly. This then results in a lower remaining debt, which is achieved either through more equity and repayment or a longer fixed interest period.

Brief update: After interest rates made a strong jump again in February, of course we are annoyed. :(

We still do not have a contract ready for signature from the construction companies. Our plan had been to finance the capital requirement for the current offer from January (without price lock) with a buffer of ~€50k. Whether this covers the cost increases is, of course, uncertain. On the other hand, with the buffer, we are already at our self-imposed upper credit limit, so we would not take on more credit even with price increases. Then the fireplace or the controlled residential ventilation would have to be omitted, or the exterior facilities would be done later.

Do banks even accept such an approach? The fact is that we can grit our teeth through further small interest rate increases, but with 3% interest over 30 years at the latest, we have to reduce our project. It is questionable whether we will reach that point in the next 2-3 months...