Okay that does indeed work to show the stair in the way that we would want. The problem then is just how that effects presentation of MEP Elements that we need to show around the stair. The output from that solution puts all elements within that region to the "<Beyond>" Line style regardless of if it is above or below the stair, they all will appear the same:
Since this is an "Up" View, the element above the stair should be showing as <Beyond>/Hidden while the fixture below the stair should be full tone; if you were looking up from under the stair, that is the first thing you would see. Moving a fixture outside the Plan Region shows it as full tone, but this is the one I want to show Hidden being above the stair landing:
So it is a nice workaround Architecturally perhaps, but we need to get this exact stair presentation without the Plan region, then these elements should show correctly. That's pointing at ADesk, not you RDAOU ![]()