Clash Report and Incorrect Revit ID Numbers

This problem sucks, there just isn’t any good way to put it….

If you’ve been using Navisworks with Revit files, you may or may not have run across this depending on how you use the Clash Reports (exported reports).  When you look at the Clash Report, there is a separate column for the Item ID, which for Revit is the Element ID.  You can use that ID number to search for the Element that is being called out in the Clash. (similar to what I discussed in this post about Revit Interferences)  At first glance, it looks great.  I can grab that ID number, go to Revit and quickly find the item in the Clash, especially if you don’t have the Navisworks model (versus possibly using Switchback if you had the Navisworks model). 

But, there is a problem when it comes to some objects.  Some objects, like Columns, Beams, Diffusers (to name a few) don’t actually report the proper Revit Element ID!!  Yeah, not so good!  From what I can tell, it’s actually calling out the Element Type ID Number and not the Element Instance ID Number.  (See this post about the props of a Revit element and what is considered Instance vs Type)  Some of you may be thinking, well can’t I just use the ID number to find the object in Revit….sorry, no you can’t.  Revit wants the Instance ID number so it can actually find and select the corresponding Instance Element.

Oh, I should mention a way to get the proper number.  Well, there actually is a couple. One being to use DWF’s from Revit instead of NWC’s.  The DWF will put the Element ID number as a suffix to the Name of the object in Navisworks.  But for many, that would require a complete change in process of getting files.  The other way, would be to have the Navisworks model open with the corresponding Clash Test and Results.  When you select a clash, the bottom pane in the Clash window will show you what objects are clashing.  If you select the Element Name, use the Select button, you can then look at the Properties to get the proper Element ID number.

I’ve reported the issue to Autodesk Support, which was escalated to the Development Team.  Hopefully (keep anything and everything you can crossed) that they can solve this issue in the next release of Navisworks!