So, now I’ve also taken a quick look at it.
I will follow it with interest and hope that there will be further updates.
I don’t see any reason to start arguing about whether it actually works and how much that translates to per square meter.
The OP is building, as we have established, in a very inexpensive region. Without having turned everything over in detail, what stands out to me is the shell construction for EUR 73,000, which is very, very cheap.
Everything else in the awarded trades is cheap but not unrealistically cheap. The leverage here is the own labor. If the OP trusts himself time-wise and nothing goes wrong (illness, etc.), then it can indeed work out that way.
According to his breakdown, he seems to be a plumber.
If I remove labor costs from the trades in my calculation, like the OP did, and add the fact that in some trades (like sanitary) more than the labor costs are saved by purchasing materials, it’s not that far off anymore.
The house seems to be standard in terms of equipment, except maybe for controlled residential ventilation.
For me, very cheap shell construction + own labor in the expensive labor cost trades.
I would be interested to know how many working hours calculated.
Then it would actually also be interesting for “new forum members.”
For 90%, the circumstances of the OP simply don’t apply. Neither the time nor the professional ability, plus most live in a more expensive region.