Share Email Facebook Twitter LinkedIn IFCFamilyInstanceExtrusionExportResults.MaterialId Property The best material id determined for the family instance. Namespace: Autodesk.Revit.DB.IFCAssembly: RevitAPIIFC (in RevitAPIIFC.dll) Version: 25.3.0.0 (25.3.0.0) Syntax C# public ElementId MaterialId { get; }Property ValueElementId See AlsoReferenceIFCFamilyInstanceExtrusionExportResults ClassAutodesk.Revit.DB.IFC Namespace