Financing a single-family house realistically?

Energy efficiency class C, with underfloor heating, gas, large plot of land we find great and would also like to maintain. I have not yet included the reserves in the additional costs. I calculate reserves per month with at least €500 extra, which is doable. Included in the additional costs are: (annual costs) Water/sewage 600 Waste 400 Electricity 1200 Heating 2000 (sufficient?) Internet 600 Property tax 600 Chimney sweep 200 Street cleaning 300 Home insurance 600 GEZ 200 so a total of €600 rounded up per month I am a security-conscious person, so a "just in time" calculation is not for me. On the one hand, I have concerns about the house that many unplanned renovations/repairs will be necessary and one cannot afford them. In an emergency it would certainly be possible to borrow money within the family, but for me that would only be thinkable in an absolute emergency. On the other hand, I also have concerns that in five years I will no longer get a good house for under €600k. Among other reasons, those already mentioned by you. The additional equity saved over this time is of no use to me either, as it will be offset by the increased price by then.

Energy efficiency class C, with underfloor heating, gas, large property we find great and would also like to maintain it. I have not yet included the reserves in the additional costs. I calculate reserves of at least €500 per month extra, which is doable. Included in the additional costs are: (annual costs) Water/sewage 600 Waste 400 Electricity 1200 Heating 2000 (sufficient?) Internet 600 Property tax 600 Chimney sweep 200 Street cleaning 300 Home insurance 600 GEZ 200 so a total of €600 rounded up per month I am a security person, so a "just scraping by" calculation is nothing for me. On the one hand, I have concerns about the house that many unplanned renovations/repairs are due and you can’t afford it. In an emergency, it would certainly be possible within the family to borrow money, but for me that would only be conceivable in an absolute emergency. On the other hand, I also have concerns that in five years I will no longer get a good house for under 600k. Among other things, for the reasons you have already mentioned. The additional equity saved in the meantime is no use to me either, as it balances out with the increased price by then.

Built in 1996, 200 sqm living space, 2000 sqm plot, double garage, upscale features, but in need of renovation [..] Price including acquisition incidental costs 430k€ (already negotiated)

EEK C means max. 100 kWh/m²/a, so 20,000 kWh, 2,000€ should be about right.