Financing double garage after completion of single-family house

The word Oldtimer always carries the prejudice of a very expensive hobby. And yes, that's the case here too, because after all, a garage is specially built for a fun vehicle. It must be a better Oldtimer than an Opel Kadett from 1989. This case doesn't make me jealous, rather pity. It's like in the thread with the old mill: Inheritance can be valuable, but also burdensome if you lack the small change.

Please report what type of garage (construction type; size) it is supposed to be.

Hehe the vintage car is a wreck and will now just be put in the garage first and then restored when there is money again. It's more of an emotional thing than an investment. It is a 6 by 6 meter garage. Slightly on a slope with a 1.5 meter retaining wall at the back and a slight decline at the front. Picture is also attached. I have no idea what it costs, but I’m happy to receive bad news from you. Regarding financing, installment loans are currently being thrown at you and the monthly installment should then fit with the government subsidy. A refinancing with the bank would then almost be more expensive, since that involves land register entries, etc. Regards Zenjamino

Depending on the equipment, e.g. electrical, E-Station, windows and door, etc. approx. 25k - 30k€...

No no, banks also offer follow-up financing without a mortgage. Just ask what interest rate they want. If the first loan is already running, you have also "fully repaid" the mortgage again.

approximately 25k - 30k€...

The last time I checked, for 35k EUR there was barely a prefabricated garage with nothing except an additional door. No electricals, no wallbox, and no retaining wall either.