Hi, just based on a gut feeling, I would also say that the whole thing is a bit expensive, especially with a rather extensive EL. Not to say that your calculation is wrong. But for that money, you can already get something finished. If I estimate your price, it is a bit more than €2500 + EL. What energy standard is the building supposed to achieve? How complex is the building structure? Sloping site? Playfulness that might not be recognized here? etc. give a bit more input in this direction.
So it is a KfW55 timber frame house with wood cladding and casement windows (Swedish style). We have 11.5m width and 8.20m depth + a bay window up to the roof measuring 1.40m x 4.00m, so a three-gable house planned. The plot is level (+/-20cm), as it was previously built on. We tore down a barn there. I had dismissed the higher price due to corona-related price increases... The shell alone costs about €240,000 (only exterior walls, interior walls, roof).