Estimate renovation costs

Since you are "only" renovating cosmetically (excluding electrical work), your cost estimate should be feasible, or even cheaper if you can/want to lay parquet/tiles yourself.

For comparison: Renovation of a condominium with 70 sqm living space (completely new electrical system with a new panel, about 70 sockets, several satellite connections, LAN in all rooms, Gira Event + new windows/balcony door triple-glazed + new white interior doors with matte finish and magnetic latch + 64 sqm oak country house floorboards + the rest tiled + completely new bathroom with tiles, sanitary fittings, high-quality shower + smoothing walls and applying painter’s fleece and painting + suspending hallway ceiling and installing spotlights) costs about €13,000. Only the electrical work is done by a professional; the rest is DIY.

Since you are "only" renovating visually (excluding electrical work), your cost estimate should be feasible, even cheaper if you can/want to lay parquet/tiles yourself.

An old building is unpredictable! Even the worst case must be considered! Rhenish greetings

and the worst case is taken into account by estimating double?

and do you consider the worst case by estimating double?

I deliberately wrote TEUR 80 and included a buffer of TEUR 20 for unforeseen events. Basically, I agree with Will and his numbers ... if your description of the ACTUAL situation is accurate and the services are contracted out. By the way, you should clarify with your utility provider whether you are even allowed to install the electrical wiring yourself. Not every provider gives their approval for this kind of self-performance; unless, of course, you are listed.

You have no idea what "might" come your way and want us, who only know the described house from your words, to provide a price estimate. So what do you expect? For example, me to lean back and write "dear TE, all nonsense, it will only cost you TEUR 10"? Or "dear TE, of course you are right and it will *only* cost TEUR 40?"

Find an expert/architect specializing in existing properties; then you will get exact figures for the renovation. For now, I stick to my number – we currently live in an old building and are renovating two houses, so I know very well what renovators have to financially prepare for ... what surprises "might" lurk.

Rhenish greetings

I would join the building expert and wpic. That roughly matches without surprises! I also advise you to carefully consider with this option whether you might as well remove a wall, install a window here and there, or something similar. This usually "only" costs a bit more and often makes an old building much friendlier. I guess with new wiring, a bit of plastering and painting, it's probably not done. For a renovation, I would also include the kitchen as a cost factor. You probably have to redo the bathroom as well, right? You can easily sink 10,000€ there.

I think we have gone way too deep into the topic.. I originally just wanted to know if there is a guideline for the renovation of individual items.. So 1sqm new parquet 50€, 1sqm plastering + painting 70€, 1 door + door frame 300€ etc.

I did not want an assessment of what or where else hidden defects in the property might be...