I just see that there is a second floor on the map but this one is empty and not used.
Maybe the second floor can be used to extend the map and add new tasks !
To acces to this new part of the map we can add a stair and an elevator (for exemple there is a « machine room » part that is not used (with the weapon box) that can be replaced with a stair/elevator.
I will add some pictures of places that can be replaced by a stair/elevator
Thank for reading !