Following on my post yesterday regarding Doors and Rooms, if you happen to have a room that is NOT at least 14 inches deep you will find that Revit is unwilling to report either its To Room or From Room parameter. If you've been reading this blog a long time you may remember a post I wrote which included a short video that mentions this issue?
A room like pictured below will work because it is 14" deep.
However the room pictured below won't be recognized and the corresponding parameters will be blank, in this case the To Room parameters.
If you are familiar with the Room Calculation Point (I call it RcP) feature it can be used to influence this issue.
Keep in mind it will also negatively affect which room you can regard as the To Room, if not for this door specifically any other doors that need the opposite behavior.
The Room Calculation Point (RcP) feature was added to doors to provide a way to change how the To Room assignment is controlled. Originally the To Room value for a door was (still is without the RcP being enabled) decided based on the side of the wall the door swings in toward.
There are doors which must swing out of a room but still belong to the room they swing from. For example a classroom's door (like shown in the images above) often swings outward to the corridor (often set into an alcove), for exiting requirements usually. However we still think of and document the door as belonging to the classroom, not the corridor.
If the door is placed so that the panel swings into the classroom (using stock doors) then the To Room parameter is assigned to the classroom. If we then flip its orientation so the panel swings out of the classroom the To Room value remains associated with the classroom (check out the post I mention above for a video of this behavior).
The RcP feature changes that behavior to alter the To Room value to follow the flip of the door orientation regardless, which means in my example, and the images above, the To Room value would change to reference the Corridor instead.
May you have sliverless designs...