TL:DR
Problem: Elements are being exported to the wrong IFC level
Solution: Check that all levels in the Revit modell are using the same "Base Height" (Survey Point / Project Basepoint)
Good morning everyone.
I've discovered a strange problem and eventually the even stranger solution.
Problem:
I noticed when exporting to IFC, that all of the elements were being exported to the wrong storey. In our case the highest building storey in our project. This didn't make any sense, as ALL the IFC literature states, that building elements will be exported to the nearest, lowest "Building Storey" Revit level.
Solution:
After scratching my head for literally hours, and many test exports, I discovered the the Reivt building levels which were assigned "Building Storey" (In our case the levels for the structural componants of the project) were using the "Project Basepoint" as their base heights, whereas the other levels (for the floor finish levels), which weren't assigned "Building Storey" (as to not appear in the IFC model) were using "Survey Point" as their base height.
Now, this doesn't explain why the building elements were not being exported to their nearest assigned building storey, but by changing the "Base Height" for ALL Levels to be "Survey Point" I am now able to export our IFC models correctly.
Happy Friday
