The following error appears in IFC Builder on the closing of elevation changes entered between two floor slabs at different levels:
The walls of the floor slabs with elevation changes must be situated on the elevation change axis.
A closing of elevation change cannot be entered in a location that is not previously interpreted by the program as an elevation change. The closing of the elevation change must coincide with the blue elevation change line that the program displays at the intersection between floor slabs when loading the “Building elements” option, “Close elevation change“. This line shows the area that the program interprets as an opening or elevation change between the two floor slabs and that must be closed.
The error can be corrected, first of all, by revising the elevation changes entered in the floor slabs from the options “Introduce elevation changes in horizontal partitions” or “Introduce elevation changes in roofs” in the “Building elements” menu, in “Floor slabs”.
The plan view geometry of the floor slabs must also be checked: they must share a line or edge of their contour, without overlapping, so that the program generates the elevation change.
Then edit the end nodes of the closing of the elevation change from “Building elements“, “Close elevation change“, “Move” and match them to the ends of the blue elevation change line.
The closing can also be removed by using the “Delete” option in the previous menu and then re-entered by selecting the nodes at the ends of the blue elevation change line:
The result can be visualised in the 3D view: