FreeCAD
Export to FreeCAD
File › FreeCAD (.FCStd) writes a FreeCAD document with every element as a solid, with its BIM type and CreaBIM id. Open it in FreeCAD, edit it, save it, and link it back.
Link a FreeCAD file
File › Import and link… and pick the .FCStd file. Its objects come in and stay linked: with Reload linked files when saved ticked, saving in FreeCAD updates them here. Assign as… in Properties turns an object into a wall, slab, door or window.
Material cards
Materials › Import materials… reads FreeCAD material cards (.FCMat), in the old and the FreeCAD 1.x formats. Opening or dropping a .FCMat file also adds its material to the project.
You can also exchange with FreeCAD through IFC, which its BIM workbench reads and writes.