Central ventilation system / also in the basement room?

From my own experience, I can only report that it makes sense to consider the basement as well. We also moved into a KfW-55 house in October and have planned the controlled residential ventilation here in the basement as well. We hang laundry in the utility/laundry room and do not have any problems with humidity in any of the rooms. The temperatures are really never below 15 degrees due to the insulated floor slab, solely because of the exhaust air from the heating room/mixing air in the stairwell. I would build it the same way again, as airing through the small basement shaft windows is rather cumbersome for me.