Exporting DWG from Revit is simple in theory — File, Export, CAD Formats, DWG — but the result is often a mess of unnumbered layers, incorrect linetypes, and geometry that doesn’t match the target CAD standard. The reason is almost always the export settings. Getting them right once and saving them as a named export setup takes thirty minutes and saves hours of cleanup on every future export.
Why Revit DWG Exports Go Wrong
Revit’s internal data structure is nothing like a DWG file. Revit uses categories and subcategories; DWG uses layers. When you export without configuring the layer mapping, Revit makes its own guesses about which Revit category maps to which DWG layer name — and those guesses rarely match the layer convention your structural engineer, contractor, or client expects.
Export Setup: The Layer Mapping Table
Before your first export, go to File — Export — Options — Export Setups DWG/DXF. This opens the Modify DWG/DXF Export Setup dialog. The most important tab is Layers. Here you map every Revit category to a DWG layer name, colour, and linetype.
The default mapping uses Revit’s own category names as layer names (A-WALL, A-DOOR, etc.), which broadly follows the AIA layer naming convention. If your project requires NCS, BS1192, or a client-specific standard, you will need to edit this table to match. You can import a layer mapping table from a text file, which is the fastest way to apply a firm standard across all projects.
Line Weights and Linetypes
The Line Weights tab maps Revit’s internal line weight numbers (1 through 16) to DWG pen widths in millimetres. Set these to match your firm’s CTB or STB plot style so that exported drawings plot at the correct line weights without any manual adjustment in AutoCAD.
The Linetype Scaling tab controls how Revit dash patterns translate to DWG linetypes. Mismatched scaling is why dashed lines often look solid or wildly oversized in the exported DWG. Set the linetype scale to match the target drawing scale to avoid this.
Export Units and Coordinate System
Set export units to match the expected DWG unit. Most structural and civil workflows expect millimetres or metres — confirm with the recipient. For site-linked exports, tick “Export rooms and areas as polylines” and ensure the shared coordinate system is active so the exported geometry lands at the correct real-world coordinates rather than at the Revit internal origin.
What to Export: Views vs Sheets
Export individual views (a floor plan, a section) when the recipient needs editable geometry to work from. Export sheets when the recipient needs a drawing ready for printing or issue. Sheet exports include the title block, which is rarely needed by a collaborating engineer — when in doubt, export views and let the recipient add their own border.
Never export a 3D view to DWG for coordination purposes — the resulting file is enormous, the geometry is often duplicated, and most recipients cannot use it productively. Use IFC for 3D model exchange instead.
Saving Your Export Setup
Once configured, save the setup with a clear name (e.g., “NCS-Structural-mm” or “Client-XYZ-Standard”). Saved setups persist in the project file and can be transferred to new projects by copying the file or using a project template. A firm-standard export setup in the project template means every project starts with the correct layer mapping without any manual configuration.
Conclusion
A correctly configured DWG export from Revit produces files that arrive at the recipient’s desk clean, correctly layered, and at the right scale. The one-time investment in setting up and saving an export configuration pays back every time a drawing set needs to be issued in DWG format.