One fact sheet I saw said distance greater than 1 meter, not a lot of help. But, there are reports that people from one apartment have affected those in one above, and that it can travel via hvac systems like is likely happening on the cruise ship, and people in apartments were told to shut off their air systems.
“But, there are reports that people from one apartment have affected those in one above”
I still wonder about that claim. It would be so easy for the two parties involved to have touched the same doorknob, etc., in the vicinity, transmitting the infection. How can they rule that out?