So I have to say, I don't necessarily find the cost estimate unusually high. Normally, the price per square meter is calculated ONLY for the house. Without garage, without additional costs, without outdoor facilities (and without basement?!). Of course, your price per square meter INCLUDING all these things is higher than the price per square meter figures you find on the internet. Nevertheless: Munich is more expensive than Hintertupfingen. We are building in a place like Hintertupfingen, so small, rural. And our price per square meter is not that much lower when I include everything, and we are not exactly building upscale!
For comparison: House with 160 m², without basement, 2 full floors and unfinished attic. No projections, recesses, bay windows or balconies. Monolithic wall construction (36.5 cm), standard glazing, standard ceiling height, controlled residential ventilation, air-water heat pump, slightly upscale electrical system, slightly upscale sanitary equipment, inexpensive roof covering (concrete roof tiles), colored plastic windows with electric shutters and partly venetian blinds, no fireplace, large double garage (6.5 m x 9 m). Construction with architect and individual contracts.
Cost estimate for house + double garage + additional costs + outdoor facilities (incl. structural engineer and architect costs): approx. €320,000. (We will contribute some own work, so the total will be reduced in the end, but I will leave that out here for comparison reasons).
That makes a price per square meter of €2000. Yes, that is €400 less per square meter than your price. But don't forget: this is Hintertupfingen, very small place, very rural area. In addition, you have, for example, thicker walls, a basement, higher ceiling height, etc... and probably a generally somewhat higher quality equipment than we do. Then there is the Munich surcharge. I actually find €2400 quite reasonable; especially if you just look at the cost of a basement, which seems to be included in your €2400/sqm!
I've already read very different numbers here in the forum!!!