I don’t want to slap a super huge miracle hut on the Earth, but rather create a home for my family and leave it to my heirs (in 50 years, if that’s okay).
It should be doable to build a small house for such a pile of money. Or not. And that’s exactly what I want to at least partially find out here.
If you build your house pretty compactly (without a basement) and with A LOT of personal labor, you might manage it. A basement already costs around €30,000 - 50,000, the conservatory about €15,000 and up, I don’t know about the balconies now. I myself inquired about a conservatory from my uncle, who works for a conservatory manufacturer. Our planned conservatory was smaller than yours, and there was supposed to be no balcony on it. And he gave me a rough estimate of €12,000. And that was a price "between friends."
So: a house with about 130 sqm, 1 1/2 stories, gable roof without balconies and no additional space above a garage, COULD be within the budget (with appropriate personal labor).
Regarding personal labor: it doesn’t save that much. As a DIYer, you need much more time, accordingly pay rent longer, interest during the waiting period or already the repayment of the loan for the completed trades.