Best practices for exporting IFC from SketchUp

Here are some tips for exporting an IFC from SketchUp.

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  • 3D models from SketchUp Pro are exported to IFC as a set of IFC objects. In order for these to become an IFC object, surfaces and edges should be grouped or combined into a component. A group or a component should have an IFC type assigned (for example IfcSlab). 3D geometry that is not grouped or made into component, and lacks the IFC classification, will not be included in the exported IFC file.
  • When the object or group has a classification assigned, customised Description and Name properties will export to IFC.
  • To use the IFC in the Tridify BIM Publishing Service the file should contain objects with IfcSlab and IfcBuildingStorey classification.
  • In SketchUp all of the geometry is created as faces instead of solids like for example in Revit. By default the front side of the face is coloured as white and the back side of a face is coloured as light blue.

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  • Many rendering engines, like the one used in the Tridify Viewer, are set to ignore back faces in order to increase performance. That's why it is important that the side of the modelled object you want to be visible, consistently consists of the front face.
  • 2D lines and 2D objects without a face, don’t export to IFC; objects must be created with a face.
  • By default, SketchUp will export the IFC with one-sided surfaces. If complex geometry or intersecting volumes are involved, orientation of faces might become random. That might cause incorrect face orientation which would appear as holes in the object after export. With each new export of the same file, SketchUp export might randomise normals again.

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    To prevent this from happening when exporting the IFC file, click Options… and make sure you have checked Export double-sided surfaces.

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  • If you want to partially export your SketchUp project to IFC, first hide any irrelevant elements and when exporting, make sure that Export hidden geometry is not selected.
  • Should you encounter problems exporting your IFC from SketchUp consider using SketchUp-IFC-Manager extension.