Building a new single-family house with KfW - costs?

0.75%? I don’t see that anywhere... The program 153 (I assume that’s the correct one) says 1.10% for 21-30 years.

You’re right, they have gone up since we built. I didn’t know.

as I said, the advisor mentioned something about €4500 and 50% subsidy.

In your initial post it says €2500, and I had assumed the 50% was not yet deducted there.

I don’t.

It’s up to you if you don’t want proof of your house’s airtightness. I would have done that regardless of the KfW. It’s also proof that proper work was done and you’re not wasting energy unnecessarily over the coming decades.

I don’t understand, I was offered a fixed interest rate at my house bank, so nothing can get more expensive.

That’s true. If that security is worth it to you. It’s a personal feeling about what interest rate development you expect in the future; nobody has a crystal ball.

True. If security is worth that much to you. It's a personal feeling what interest rate development one expects in the future; no one has a crystal ball.

I am someone who prefers to pay a % more but be safe. The probability at the current interest rate level is much higher that they will rise than that they will fall. And even if they should fall - to where? To 0.5? Ok, but that wouldn’t be a problem either.

The probability at the current interest rate level is significantly higher that they will rise than that they will fall.

On what is this assumption based, if I may ask?

What is this assumption based on, if I may ask?

On fear. For whatever reason. Given the conditions, I would finance for 10 years and that's it. What on earth is supposed to happen?

Well, first of all, it is actually just an assumption, but if you look at the interest rates of the last decades, they have always been higher than now. And since interest rates are now approaching 0, it is (purely logically) more likely that they will rise than fall further. Of course, you could also say now that they can go negative, see overnight money etc. – but I don’t believe that when it comes to mortgage interest rates. That’s why it is more likely for me that interest rates in 10 years will be at 4% rather than 0%. It might sound strange now, but that's how I derived it. This now has nothing at all to do with economic or business factors.

Based on fear. For whatever reason. Given the conditions, I would finance for 10 years and that's it. What exactly could happen?

The statement is not entirely wrong, fear is just a word with a negative connotation. But maybe you have to know more about me. I am financing alone and everything is already tightly calculated. On the other hand, one could also say you finance as long as possible because you currently have an ailment and you don't know if you will even live to see the end of the financing - so you could say. I am simply someone who likes to have everything under control, and if I like that when buying a TV, then even more so with half a million for a house.