CET supports the import and export of models from SketchUp. You can import a drawing you have made in SketchUp or use the 3D Warehouse to browse a massive library of all kinds of symbols to use. Add these objects to your drawing to achieve a more realistic impression. 

The SketchUp Extension is free on the Marketplace.

After downloading and installing the Extension, you'll have a new SketchUp component tab. Here, models can either be imported from or exported to a .skp file or imported from the 3D Warehouse.