Property financing and subsequent construction project

If you know that you wanted to start in 1-2, I would rather choose a sprinter or a strong bench.

(May 2018: 1.45% at the local Sparkasse)

I just called Berliner Sparkasse, unfortunately they don't offer anything like that. So far I have only found DKB and DSL...

has been resolved - question has already been answered!

Financed our property variably at DKB. Since the interest rate level is almost the same again, I can tell you that with, for example, a loan-to-value ratio under 60%, you could end up somewhere around 1.5%. Sounds like a lot at first, but you can repay any amount every six months. Because of this, for example, we paid off our property in 1 year and paid a ridiculous 300€ in interest on 55k€.

The following banks are also known to me for interim financing:
Gladbacher Bank eG and Bankhauses Ellwanger & Geiger

Gladbacher Bank eG

They do not finance themselves, but act as intermediaries ;-)