Is each Type identified by its name or by its ifcguid?

If I push the updated model from Revit via Speckle, and the designers have changed a character in a name, will I loose the mapping or not?

Hi’ @SOP

Yes, you’ll lose the mapping. The EPD mapping is keyed on the combination of the type and material name, so if either of those changes - even a single character — the basis for keeping the mapping is no longer valid.

The important point is that once the identifier changes, we have no way of knowing what actually changed. A single typo correction and a genuine change - say an inner wall becoming an outer wall - look identical to us: both just present as a new identifier. We can’t distinguish a harmless edit from a real change in the building element, so we can’t safely carry the mapping over in either case.

That said, this isn’t the first time we’ve heard this, so we’ve started documenting a process where the user gets to decide whether a change should keep the mapping or not. That way the call is in the hands of the person who actually knows what the change means.

Best,
Martin

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