Hello Stivi83it,
as a financing broker, I can tell you that there are countless possibilities for financing planning. You are talking about KfW grants and low interest rates, but these only make up a fraction of your entire financing. I would recommend that you sit down with a specialist and then discuss the construction project completely. There are situations where a KfW loan does not fit or where it fits very well. The financing should be perfectly tailored to your needs. Factors such as loan type, term, collateral, flexibility, interest rate, etc. play a role. No financing is the same, so I recommend a consultation with a financer in advance. After that, you will certainly be "back on the right track" :) If you have any questions, feel free to get in touch. I wish you much success.
Best regards
André Empen
Gecko Maklerverbund