IFC-Export contains empty objects

Dear all,

I’m struggling with exporting an IFC with GG. When I check it with an IFC-checker, i get 100s of errors. When I looked closer at it, i recognised, that there are 100s of emtpy objects:

#26292= IFCBUILDINGELEMENTPROXY(‘1iB8BzDgv2yRH3oZ1Camdu’,#26288,‘NOTDEFINED’,,,,,,);
#26293= IFCBUILDINGELEMENTPROXY(‘3WgOskN1j3fhurrjwpSnLz’,#26288,‘NOTDEFINED’,,,,,,);
#26294= IFCBUILDINGELEMENTPROXY(‘01DuhVW$fDaQBtozcLuetr’,#26288,‘NOTDEFINED’,,,,,,);

Everytime I run the export, I get more of such empty proxy elements. Any idea, why this happens?


Hi Marco,

Thanks for posting. First of all, great that you are using an IFC checker.
I can only hope this becomes more common across Information exchanges, and the checks improve.
As you’re probably aware, the early influences on GG developing IFC export from Grasshopper
was primarily to generate Revit models. It started over 10 years ago, well before Rhino Inside was a possibility.
The empty elements relate to identifying elements now obsolete/redundant in our version of element tracking (the key being the globalid which was saved on each object in Revit). If you looked at the owner/history object on these empty objects, it would show a deleted status. Our revit plugin would process this and remove the obsolete elements from revit.
The obsolete elements is on as a default setting (I’ve not heard any reports that any other implementation had problems with them), but you can prevent them from being included in the export by right clicking on the Bake component and removing the “Identify Obsolete” option.

Let me know if this doesn’t help.



Hi Jon,

thanks a lot for your fast and detailed answer. Now, my IFC checker is happy: