Isn't it even more astonishing that an architect plans this way with the objective from the beginning and then confirms again before submitting the building application 3 weeks ago that the budget is sufficient?
Isn't it always said here in the forum "Beware of the floor main contractor and the additional costs, an architect is your (paid) friend"?
To be honest, this rather doesn't surprise me now. We had all the offers 6 months before the building permit to realistically calculate the financing. The result was €365k, with incidental costs it is already €420k now. I assume that my private buffer of €20k, which I have saved for the construction, will be added on top of that. Possibly also the home ownership grant of €10k. The kitchen, which I will start saving for from September, isn't even included yet.
For example, our front door costs €2,900 (standard dimensions in aluminum). Just look at your entrance area alone. The door will cost you at least €5,000 and you still have the entire entrance area with a canopy.
The canopy around the terrace is also not standard.
You spent as much as possible on the building structure. If you then have an architect who has slept through the price developments of the last 3 years (for whatever reason), then this happens. I also believe that you would have exceeded the cost estimate by tens of thousands of euros even 3 years ago.
The problem now is to cut down, because the costs aside from the basement and the garage apparently distribute quite evenly across all trades.
With such a high cost overrun, the basement would be the first thing I would cut out. As long as it is not necessary because of the terrain.
Otherwise, the house must be smaller plus all add-ons gone. In other words, either one big cut or many small ones.