When you export an IFC file, the export process creates an IFC file and a LOG file.
Only a currently active drawing can be exported to IFC.
To export Autodesk Civil 3D objects to IFC, they must first be converted to 3D solids. You can convert TIN surfaces, corridors, pipe networks, and pressure networks to 3D solids using commands included in Autodesk Civil 3D. After the objects are converted to solids, you can export the drawing to IFC using the option to export solids.
Drawing coordinate systems are automatically included in IFC export and import when using version 4. If a drawing is assigned a coordinate system, the information is included in the IFC export. When the IFC file is imported, the new drawing that is created is assigned the coordinate system found in the imported IFC file.