Hi

You have to possibilities. The easiest, make the CADmep save the information in AutoCAD with "Save Graphic with Drawing" (in Edit Main Database>Takeoff>CAD Settings>General) , Have the consultant install the CADmep object enabler (allows AutoCAD to read the CADmep data https://knowledge.autodesk.com/support/fabrication-products/downloads/caas/downloads/content/autodes...)

Check this thread.

https://forums.autodesk.com/t5/fabrication-cadmep-forum/how-to-make-fabrication-cadmep-viewable-by-o...

Hope it helps

Regards