How to Edit CAD Drawings in Revit?

Understanding CAD Files in Revit

Editing CAD drawings in Revit requires a specific process due to the differences in how these two software operate. CAD files, primarily created in AutoCAD, are flat, two-dimensional representations, while Revit is a Building Information Modeling (BIM) tool that handles three-dimensional modeling and data management. To enhance your Revit projects, an understanding of how to efficiently manage and edit CAD drawings is essential.

Preparing CAD Files for Revit

Before importing a CAD file into Revit, it is crucial to prepare it by simplifying the content:

1. Open Your CAD File: Use AutoCAD or any compatible software to access your CAD drawing.
2. Clean Up Layers: Reduce the number of layers to a manageable count. Ideally, consolidate to only essential layers to simplify the transition.
3. Remove Unnecessary Elements: Eliminate any hatch patterns or unused objects that may clutter the drawing, making it easier to work with once brought into Revit.
4. Save Changes: Save the cleaned-up file in a format compatible with Revit, such as DWG or DXF.

This preparatory work ensures that Revit can interpret the drawing more effectively, reducing potential complications during the import process.

Importing CAD Files into Revit

Once the CAD file is ready, follow these steps to import it into Revit:

1. Open Revit: Start by launching Revit and opening the project where you want the CAD drawing.
2. Access Import Options: Navigate to the "Insert" tab at the top of the interface.
3. Select Import CAD: Click on the "Import CAD" button found within the Import panel.
4. Choose the CAD File: In the dialog box that appears, browse to locate your cleaned CAD file. Ensure that you set "Files of type" to DWG or the respective file format.
5. Adjust Import Settings: Specify any necessary options, including units and positioning. This is crucial to ensure that the CAD drawing aligns correctly with your Revit model.
6. Complete the Process: Click the "Open" button to finalize the import. Once the file is in Revit, it will be displayed within your project.

Editing Linked CAD Files in Revit

To modify a CAD drawing that has been linked to your Revit project rather than imported, follow these instructions:

1. Manage Links: In Revit LT, go to the Manage tab and find the "Manage Projects" panel, then select "Manage Links."
2. Select the Linked File: In the Manage Links dialog, navigate to the CAD Formats tab. Here, find the linked CAD file that you wish to edit.
3. Reload the File: Click on the "Reload" button. This will allow you to replace or refresh the existing linked file with any updates made in the original CAD document.
4. Confirm Changes: After reloading, click "OK" to finalize your changes.

Keeping your linked CAD files updated is vital when adjustments are necessary, ensuring that the Revit project reflects the most current information.

Importing and Editing Geometry from CAD Files

After importing CAD files, you might want to further manipulate the imported geometry:

1. Select the Import Symbol: Click on the imported CAD file within the project.
2. Modify the Geometry: On the Modify tab, go to the Imports panel and use the "Explode" feature (choose Partial Explode to retain some original data). This enables you to break down the imported objects into editable elements.
3. Adjust Positioning: Once exploded, you can move or edit the geometry using its shape handles. Ensure you assess the changes to maintain alignment within your Revit model.

This process allows for greater flexibility in how imported designs are utilized within your Revit projects.

Frequently Asked Questions

1. Can I edit CAD files directly in Revit?
No, Revit does not allow direct editing of CAD files. You need to modify the original file in AutoCAD or a compatible software and re-import it into Revit.

2. What file formats does Revit support for CAD imports?
Revit supports several CAD file formats, including DWG, DXF, DGN, and SAT, allowing for a wide range of drawing integrations.

3. Is there a limit to the CAD file size I can import into Revit?
While there is no strict file size limit, excessively large CAD files might not display correctly in Revit. It’s recommended to clean and simplify CAD files before the import to ensure optimal performance and visibility.