The Many Ids Of a Revit Element and How to Work With Them – ElementId, UniqueId, DWF Guid, IfcGuid

The Many Ids Of a Revit Element and How to Work With Them – ElementId, UniqueId, DWF Guid, IfcGuid

As software and standards mature and even become archaic, they inevitably attract baggage along the way. Years of technical debt amassed by well-intentioned developers and product managers will be paid for by us and our children.

This is particularly evident when we start talking about the Id of Revit elements, and the IFC GUID syntax. As most of you are aware, Revit carries a number of different identifying attributes for each and every element. Here is a basic list:

  • Element Id – the numerical form of a Revit Id, you can interact directly with this using the Select By Id command in Revit
  • UniqueId – “A stable unique identifier for an element within the document.” This is not a correctly formed UUID, but rather a concatenation of a standard UUID for the Revit EpisodeId (session based), along with the Revit element Id. From Jeremy’s post: similar to the standard GUID format, but has 8 additional characters at the end. These 8 additional hexadecimal characters are large enough…

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