Hi,
I set this up two-three years ago for demo purposes. I used the help text (SAP Patient Management --> Basic Data --> Hospital Structure --> Building Structure --> Maintain Building Units for Care Unit Graphic), which I found very helpful .
Regarding the coordinates, they should be positive integers, so you should choose your axes to originate in the 'lower left hand corner' when drawing your structure.
Keep in mind that beds have a minimum size (2x2), so if you want to fit ten beds in a room, the room should be sufficiently large, e.g. 15x6.
I found that, although this functionality looks good in demo's, it isn't actually used very much (at least: not that I have seen).
Good luck with implementing this!
