Hi Johnes, I appreciate your reply 
I’m a relative newbie to Dynamo and not all that familiar with python yet…just some codeblock basics. I tested your python script and indeed it can display metric or imperial units however if I altered the unit settings on the fly in Revit the Python script does not pick up the active state of the file. I can refresh by closing the dynamo graph and opening again. I’m wondering how it could pick up the current state of the active document? Further to this though I was looking to delve a bit deeper than identifying Metric or Imperial and find the unit format…whether that is in meters, millimeters, feet and inches etc. Looking at one of Jeremy Tammik’s posts on units http://thebuildingcoder.typepad.com/blog/2008/09/units.html I found that perhaps what I am looking to query is Parameter.DisplayUnitType ?? I’ve tried altering the code you provided to suit but haven’t been able to find the right syntax.
