If you’ve worked on projects with a long history, chances are you’ve inherited a library full of legacy CAD details. While these files still hold valuable information, they don’t always fit neatly into a modern Revit workflow.
Instead of redrawing those details from scratch, you can use them as a foundation. By importing legacy CAD files into Revit and tracing over them with native tools, you can quickly transform outdated details into clean, standards-based Revit content.
In this blog, we’ll walk through a practical workflow for converting legacy CAD details into fully functional Revit details, helping you save time while improving consistency and model performance.
Get Ready to Create Your Detail
AutoCAD
-
If possible, evaluate the CAD file first before bringing it into Revit. Open it in AutoCAD and clean up if needed.
-
-
-
Remove unnecessary layers.
-
-
-
Check units and scale.
-
-
-
Purge unused objects.
-
-
-
-
-
Check measurements and verify they are correct.
-
-
Revit
-
Create a new drafting view.
-
Set the scale.
-
Create any detail lines or filled regions.
-
Be familiar with the Temporary Hide/Isolate tool in the View Control Bar.
-
Always measure anything imported from CAD as CAD tends to have modified dimension values. Revit will not allow you to modify the dimension values.
Create the Revit Detail
-
In the Revit project, in the View tab>Create panel, click Drafting View.
-
Enter a name and set the scale.
-
In the Insert tab>Import panel, click Import CAD. In the Import CAD Format dialog box, select the CAD file to import. Change the Colors to Black and White, keep the other default options, and click Open.
-
Zoom out so that you can see the imported detail by typing ZF to zoom to fit.
Note: Some CAD files import cleanly, like the tree planting detail for landscaping shown below, and need no adjustments. However, outdated files or imports with mismatched fonts, overlapping lines, or text often require attention. Avoid exploding DWGs in Revit, as this can add unwanted line types, text types, and elements, making the project heavy or even corrupt. Let’s proceed without exploding the detail.
-
Ensure all dimensions are measured accurately. CAD files can contain altered dimension values, whereas Revit maintains precise measurements that cannot be changed. Therefore, you may need to adjust the lines you trace.
-
Start the Detail Line tool in the Annotate tab>Detail panel.
-
Set the line type and choose Pick Lines in the Draw panel.
-
Hover over the linework. Once it highlights, click to place a detail line. If there are many lines, such as the foliage of a tree, press <Tab> to select the connected lines.
-
Select the CAD file and in the View Control Bar, set Temporary Hide/Isolate to Hide Element. Verify that you selected all the correct lines and clean up any that you missed.
-
To add a filled region, in the Annotate tab>Detail panel, click Region. In the Type Selector, select the correct filled region.
Hint: Use existing filled region types that resemble the needed hatch pattern.
-
Use the Draw tools to draw one continuous and closed line. Note: You will get a warning dialog box if lines overlap with the lines highlighted in the drawing, so you can fix them.
-
When finished, click the green checkmark in the ribbon.
Hint: If you use the rectangle draw tool, you can adjust one corner of the rectangle independently of all the other lines to give it an angle.
-
In the Annotate tab>Text panel, click Text and set the leader type in the Leader panel.
-
In the Type Selector, set the text type, then add text to the view. (You can add the new text past the existing text, as shown below, then at the end, you can use the Align tools to quickly align it closer to the detail.)
-
When finished with all the annotations, hide the CAD file and adjust one of the text and leader lines closer to the detail.
-
Select all of the text notes that need to be aligned. In the Modify | Text Notes tab>Multiple Align panel, click one of the options to align the text notes to be closer to the detail. Adjust the leader lines as needed.
-
Show the CAD file again, then add dimensions by using the Aligned Dimension tool in the Annotation tab>Dimensions panel.
Hint: To display text instead of a numerical value, double-click on the dimension value and select Replace with Text, then type the desired text.
If you did not measure before you started drawing and now your dimensions are off, you can do a few things to modify this without having to redraw. Double-click on your dimension value and do one of the following:
-
If it’s an approximate measurement you can add a symbol such as ~ or edit the dimension text and add text (such as APPROX.), then the value (such as 3'-6").
-
In the Replace With Text field, right-click and select Insert Unicode control character>US Unit Separator (Segment separator), then enter the correct dimension value.
-
Hide the CAD file again to verify you have everything needed. You can hide the CAD file in the view if you need it reviewed first, or you can select the CAD file, unpin it, and delete it.
About the Author
Follow on Linkedin More Content by Cherisse Biddulph
