we have already designed, sized, and modeled our ducts; we are now told we need to use duct liners not insulation. Is there any way to have Revit automatically increase the duct size to show the actual size of the duct while maintaining the inside clearance of the duct that is now defined by the liner? Otherwise we have to leave the duct the same size but then we get clash detection issues because we are not modeling the realistic size of the duct. Thanks for the help.