I have revised it again. The house can be at 499.5m and the carport as well. The storage room then with limited ceiling height and/or a bit lower. The path behind the storage room remains.
The carport (6*5m) has a 1 m roof overhang towards the street, which continues as a canopy up to the entrance.
The window in the WC should then face west.
The max. building height when rotating the house is 506.83m, which is 20 cm more knee wall (according to my calculation 1.7m at 30° roof pitch).
If the floor heights are reduced, there are a few more centimeters.
The reference height is the average of the 4 corner points of the house with the intersection of the original terrain. In my example that is 498.83m + 8m (max ridge height). In the draftsman’s design it is 498.62m.
The basement protrudes only 1.1m. The tower is not quite as extreme then.
I won’t say anything about the floor plans, there are experts here for that.