The most common CAD formats are .dwg and .dxf. These formats are proprietary and most often associated with Autodesk and AutoCAD, but other programs also use them. SketchUp subscribers can import CAD files into their models, and export their models as CAD files for use with other software.

Importing CAD Files

When you import a CAD file, SketchUp attempts to translate the entities in that file to SketchUp entities. SketchUp supports the following imported CAD entities:

• Arcs
• Circles
• Faces
• 3D Faces
• Layers/Tags
• Lines and Line Styles
• Materials
• Polyline-based Solids
• Nested Blocks
• AutoCAD regions
• Point
• Ellipse
• Spline
• Raster Images
• Solid Hatches

Sketchup does not support the following CAD entities:

• Proprietary ADT or ARX Objects
• Dimensions
• Text
• XREFs

Before you import your CAD file, you can do a few things to make sure all the data you need imports into SketchUp and streamline the import process.

To prepare your file:

• Change unsupported elements – If you need to import unsupported CAD elements into SketchUp, try exploding those elements in CAD, transforming them to elements that SketchUp does support.
• Delete unnecessary layers – SketchUp discards any entities that have no 3D relevance. The layers those entities were on will remain, creating empty tags in SketchUp. To avoid this, purge these unused layers before importing.
• Move geometry close to the origin – Geometry that's too far away from the axis origin can cause performance issues. Check the placement of geometry in your CAD file before you import the CAD file into SketchUp.
• Reduce the file size as needed – The smaller your CAD file size, the quicker and easier the import. Files larger than 15MB may cause performance issues. To reduce the file size, only import geometry you need or consider breaking your CAD file up into multiple files.
• Save your CAD file in a SketchUp-compatible format – When SketchUp imports a CAD file, SketchUp strips the information to its basic geometric components. Older CAD formats may not work well with SketchUp. To make sure your file imports without issue, save CAD files created in older versions to a more recent one.

After preparing your file, follow these steps to import a CAD file:

1. Select File > Import.
2. Locate the CAD file you want to import.
3. Select AutoCAD Files as your file type.
4. Click Options. Adjust the following as necessary:
   • Under Position, select Preserve Drawing Origin to place the imported geometry at the origin defined in the .dwg or .dxf file. Leave blank if you want to place the imported geometry near the SketchUp origin.
   • Selecting Import Layers as Groups creates groups corresponding to the imported CAD file’s layer structure. These imported layers still have their own tag and also have corresponding, grouped geometry.
   • Selecting Import Linework Flattened sets the Z-value of imported geometry to 0, eliminating Z-axis discrepancies.
   • Selecting Merge Coplanar Faces tells SketchUp to remove triangulated lines from planes.
   • Selecting Orient Faces Consistently tells SketchUp to analyze the direction of imported faces and orient the faces in a uniform manner.
   • Selecting Import Materials imports materials from the original file. Unselect to choose not to import those materials.
   • Choose a scale option the imported file will use. Your options are Model Units, Inches, Feet, Yards, Miles, Millimeters, Centimeters, Meters and Kilometers.
5. Click OK.
6. Click Import.

After importing your CAD file, there are some known issues you may come across:

• The size or scale may not import as expected. This is especially true if you weren't sure what unit of measurement was used to create the CAD file.
• Lines may not connect to form faces. Hunting down all these little gaps can be difficult.

Before you start using your imported file, follow these steps to make sure the imported file is ready for modeling:

1. Check the size of the imported CAD geometry and scale any incorrect measurements as necessary.
2. Make sure the CAD geometry is a single group. If you already have grouped geometry in your model, SketchUp will automatically group the imported CAD geometry.
3. Line up the floor plan with SketchUp's drawing axes.
4. Delete any extra tags and give the CAD group its own tag.
5. Adjust the edge styles as necessary.

Exporting to a 2D CAD Format

When you export a SketchUp model to a CAD format, SketchUp translates data in the following ways:

• SketchUp faces are exported as a triangulated polyface mesh with interior hidden lines to better simulate SketchUp geometry.
• SketchUp uses the current unit of measurement as a reference for translation to a .dwg or .dxf file.
• Duplicate line entities aren't created on top of a p-line entity.

To export a model as a 2D CAD file:

1. Before you begin the export process, make sure your model is in a standard view in Camera > Standard Views.

   Note: Before exporting, make sure your model is in a Standard Camera view with Parallel projection enabled. This can help make sure the scale of your model is preserved. For more information, see Viewing a Model.
2. Select File > Export > 2D Graphic.
3. Choose a location to export to.
4. Select either the .dwg or .dxf file type.
5. Click Options. Adjust the following as necessary:
   1. AutoCAD Version – Choose the version of AutoCad you wish to export to.
   2. Drawing Scale & Size – Full Scale is selected by default. Deselecting that box allows you to set a custom scale.
   3. Profile Lines – Customize how profile lines appear in your exported file.
      • Select None to export profile lines at the standard width.
      • Select Polylines with Width to export profile lines as AutoCAD polylines.
      • Select Wide Line Entities to export profile lines as AutoCAD wide line entities.
      • Separate on a Layer is selected by default and creates a layer for profile edges.
   4. Section Lines – These options are available when exporting section lines or a section slice. See Slicing a Model to Peer Inside for details on how these options work.
   5. Edge Extensions – Some CAD applications might have problems recognizing line endpoints and intersections when your model uses SketchUp line extensions. Deselect Show Extensions to toggle extensions off in your exported file. If you leave Show Extensions selected and deselect the Automatic, you can enter an exact length for line extensions in the Length box.
6. Click OK to return to the export dialog.
7. Click Export.

Exporting a SketchUp Model as a 3D CAD file

When you export a SketchUp model as a 3D CAD file, you can export the entire model, or just a selection of entity types by following these steps:

1. Select File > Export > 3D Model.
2. Navigate to the location where you want to save your exported file.
3. Select either .dwg or .dxf as the file format for your exported file.
4. Click Options.
5. Select the AutoCAD Version you'd like to export your file to.
6. Select each type of entity you want to include from the following options:
   • Faces
   • Edges
   • Construction Geometry
   • Dimensions
   • Text
   • Materials
7. Click OK.
8. Click Export.