Purchase without equity, L-Bank "Living with Child" + KFW funding ok?

Thanks for the answers :)

Best with an example:

If the property costs 400,000 EUR and you get 100,000 EUR KfW funding, 100,000 EUR from the L-Bank, and finance the rest through your main bank. Do you then need the recommended minimum 10% equity on the 100,000 EUR or still on the total costs plus additional expenses?

Or can you theoretically reduce the "necessary" equity with the loan?

Regards

recommended minimum 10% equity

Where does the recommendation come from?

If the property costs 400TEUR

... then the recommendation is to provide between T€ 100 and T€ 125 equity. This is currently the recommendation as a minimum or a wish from banks.

reduce the theoretically "necessary" equity with the loan?

Normally no. Equity is still - how often do I have to write this? - capital (= money) and not a loan.
If your creditworthiness fits, a lot is possible. If it is tight, then basically more or less nothing.