The default work flow for collaboration between ArchiCAD and other BIM applications is IFC. The IFC Translator settings are critical to a smooth translation of information between different applications e.g. ArchiCAD and Revit Structure. The typical workflow involves using the other consultants model as Reference information.
When using this reference model workflow accurate depiction of the model is critical. The IFC translators in ArchiCAD allow for two ways to represent complex modelled elements during export. Extruded Geometry and Precise Geometry (BREP) This is set in the IFC Translation Setup > Export Options > Complex Elements Options