When to use equity?

KfW must be applied for by your bank before construction begins, including proof from an energy consultant.

But then take out the entire loan at once, because refinancing is expensive.

That means if KFW, then a decision would also have to be made before construction begins!?

That makes sense if you are financially strong enough to invest your equity elsewhere for a higher interest than you pay on your loan interest.
If you take out the mentioned 200,000 on a 10-year full repayment loan with your credit rating, I estimate the interest rate to be currently < 0.6%. But you have to decide that and weigh the risks.

Regards
Specki

The cheapest offer currently was 0.47 percent fixed for 10 years with 5% special repayment per year and full repayment.

I was faced with a similar decision and chose a peaceful, debt-free sleep despite building a house. Missed returns from credit-financed speculation don’t matter to me, and I can still speculate when there is sufficient positive equity beyond the house again. Call me boring, but I don’t need the missed money right now, and debt from gambling would be annoying.

That’s the kind of person I am too. I’m very conservative and have actually done quite well with it... what use is 2-3 percent interest if you can’t sleep peacefully anymore? It only makes sense if the money is really extra and you have no other use for it.

That means if KfW, then a decision must be made before the start of construction!?

Yes. Unless you provide equity as collateral for the KfW loan with only a 4-year term (see my thread, but that probably makes little sense for you) or the bank likes you so much that they give you the KfW loan unsecured (might even work for me). As soon as you register a mortgage, you should take the full amount.

The cheapest offer currently was 0.47 percent fixed for 10 years with 5% special repayment per year and full amortization.

Do you have two residential units? Then go full KfW. Otherwise, you have to calculate.

Volkswagenbank offers 1.3% interest on 10-year fixed deposits with very high deposit protection and AAA rating.

With such assets, I would finance as much as possible and repay as little as possible.

Maybe you can also save financing costs by using the mentioned fixed deposit as collateral for the mortgage, instead of registering a land charge.

Yes. Unless you provide equity as collateral for the KfW loan with only a 4-year term (see my thread, but that hardly makes sense for you) or the bank likes you so much that they give you the KfW loan unsecured (might even work for me). As soon as you register a land charge, you should take out the full amount.

Do you have two residential units? Then fully KfW. Otherwise, you have to calculate.

No, it is only one residential unit.

Volkswagen Bank offers 1.3% interest on 10-year fixed deposit with very high deposit protection and AAA rating.

I would finance as much as possible and repay as little as possible with such asset conditions.

Maybe you can save financing costs by using the mentioned fixed deposit as collateral for the mortgage instead of ordering a land charge.

Well, I don’t know... it’s more a matter of mindset. I think I’m too conservative for that ... for me it’s more important to be able to say that the house is paid off.

You are thus foregoing good money and thereby wealth accumulation/retirement provision. A paid-off property cannot be eaten and it also needs to be maintained.

Has the equity been built up independently or was there help/one-off effects?

Always just money money money. As if there isn't anything more important in the world.
If the equity has mostly been saved up by oneself, then securing retirement should probably be the smallest problem anyway.
I can understand that having a fully paid-off home is more important to someone than a few € more in the account.