Financing and interest rate fixation when buying a house - remaining debts

My roofer rated the house as very good yesterday, but the roof still needs to be repaired, at least for the next 5 years, cost 20000€.
Heating, old out, new in about 12000€.
etc., that will then be too expensive for us, so we will let it go.

I will now set aside the monthly amount for one year that the financing would have cost, then we will see if it would even be possible.

Regards and thanks