Can drywall be glued directly onto concrete?

is insulated from the outside

You wrote 5-10cm, that is not enough. Therefore, are the basement rooms designated as living spaces in the building permit?!

You wrote 5-10cm, that is not enough. So are the basement rooms planned as living spaces in the building permit?!

The house is being built in Croatia, where it does not get colder than 0 degrees, and only at night. The basement I am currently using, but only as an office, has no insulation at all, just a 25 cm concrete shell and v3 waterproofing membrane against moisture. Always 18-20 degrees without heating. It is not common here to insulate as thickly as in Germany.

Air has hardly any insulating function behind [GK-Platten], because the air must be still for that. As soon as it can move freely, the function is gone. In [GK], the air is not still. That is why a [WDVS] is also glued using the point-bead method and not just the point method.

The question is a different one. I don't care about the insulation; I am only interested in whether there could be problems with the condensate.

Leave a small gap at the top and bottom through which air can circulate. Then there will be no problems [so and so].

I still recommend plastering... just try it on one wall, if it doesn’t work out you’ll hardly lose anything. Okay, a few centimeters because you would then stick the drywall onto the plaster. What does that matter? If you can come to terms with it, all the problems drywall might bring you will be solved in one go. Just be brave, it will work out.