Is it possible to build a new building for 900€ per m²?

Thank you very much for the feedback. I think a bit more soberly and say: (zusammen-)gezählt wird zum Schluss. But I remain curious and am happy for you.

Thank you very much for the feedback. I think a bit more soberly and say: (counted) will be done in the end.
But I am also excited and happy for you.

It’s quite possible that in the end we will land at 1800€ or 1900€ per m2, but I have a buffer and my construction prices are, based on what I read, still well below average. I am definitely looking forward to the house construction and the new phase of life. If things go even half as well as expected professionally and privately, then in 3-4 years I can also start breeding German Shepherds, which of course wasn’t possible in the apartment until now. The anticipation for the house and moving in is huge at the moment.

It’s quite possible that we will end up at 1800€ or 1900€ per m2 in the end, but I have a buffer and my construction prices are still well below average based on what I’ve read.

I have to correct that. Your construction prices are quite normal like everywhere else. Maybe even expensive. But you compensate through massive personal contributions. You must not forget that.

Personal contributions in: dry screed, floor coverings, interior plaster, windows and front door, interior doors, bathroom and also bathroom fittings and an infrared heating system.

Let professionals do all that and you’ll end up at the prices you read about here. If you were to commission the personal contributions for, say, 60k with craftsmen (100€ per sqm for coverings or 15k for painting etc. are not uncommon), then you’d also end up “only” somewhat below the +/- 3,000€/sqm living area. I don’t want to take away your good feeling, just to point out that you are exchanging money for personal contributions (which I actually think is great, so you can build your own house).

Yes. However, one must consider that a small bungalow is significantly more expensive per m² than a town villa. Because both need the same expensive roof, both require 2 bathrooms or a bathroom and a guest WC, etc.

At Town & Country you can get the bungalow with 90m² in an expensive region from 240,000 EUR, so 2,700 EUR/m². The town villa with 154m² costs around 320,000 EUR, so 2,100 EUR/m².

With 60,000 EUR for craftsmen, it would still be around 2,500 EUR/m². Far from 3,000 and that with a small bungalow, so the most expensive thing you can build at all when it comes to EUR/m².

This general stuff is good for a first assessment, but it does not replace a real calculation?

This flat rate stuff is good for a first assessment, but it doesn’t replace a real calculation, does it?

No. But in the end, the "flat rate stuff" still fits quite well. Whether a bar of chocolate costs 99 cents or €1.09 – everyone says that the price is similar. If the house costs +/- €3,000, then €3,300/sqm suddenly seems insanely expensive and €2,700/sqm outrageously cheap. Both prices only deviate by 10%. And the 60k = €700/sqm from the OP is just thrown in. We will never see a comparable price because the same house exists only once. But it is clear that he would also end up around +/- €3,000/sqm. And not at €900/sqm – with additional expenses (EL) he is already at least doubling the originally mentioned figure.

It's quite possible that we will end up at €1800 or €1900 per m2 in the end, but I have a buffer

That's what I call a sunny disposition: aiming for nine hundred as a target, accepting one thousand nine hundred as a result, and calling the difference a "buffer." Splenderrific!