How to create determine the orientation of walls from revit (North, South, West, East)

[Mark.Ackerley]

Good shout, Clockwork and Rhythm have similar as well, I found this post helpful…

Wall bounding the room to North,East,West ,south....!

I believe your problem was with your list structuring between your walls and your room elements… The Archi-lab Room.Boundaries node will give you a list of curves and wall elements grouped by your input rooms, so then the vectors will be grouped and evaluated in the Wall.NorthSouthEastWest node by room: [wall orientation by room] The sublists are for each room; note that there are wall elements (ids) that appear in both North & South because they are in respect to the room.