Using Subcategories Effectively in Revit

Application of Subcategories in Revit

Unlike Autodesk CAD, which uses layers to organize and manage drawing information, Revit structures project data based on object categories. To further segment these categories and enable more flexible control over elements, Revit introduces the concept of subcategories.

Utilizing subcategories allows for multi-view and multi-angle control over families within a project. Below, we explore specific applications of this feature.

Application 1: Displaying Different Content of the Same Family in Different Views

Sometimes, it’s necessary for certain families to show different parts of their content depending on the view. In other words, a family instance (with a fixed type) might need to display varying content across multiple views, which cannot be managed solely by the level of detail. This can be achieved through subcategories.

For example, consider a sample family that should display a rectangle in 3D View A and a circle in 3D View B.

Steps:

1. Create separate subcategories within the family, such as “Rectangle” and “Circular.”
2. Assign each component of the family to its respective subcategory (“Rectangle” or “Circular”).
3. After loading the family into the project, turn off the unnecessary subcategories in each specific view. For instance, in 3D View A, turn off the “Circular” subcategory; in 3D View B, turn off the “Rectangle” subcategory.

This approach ensures that the family displays different content depending on the view.

Application 2: Assigning Layers for CAD Export via Subcategories

When exporting DWG files from Revit, you often need to assign specific layers to different element categories following 2D drawing standards. However, Revit’s limited default categories for layer mapping may not meet all requirements. Subcategories offer a solution by allowing additional layers to be defined within families.

For example, in some standards, different door types must be exported to CAD with distinct layer names: fire doors to “A-DOOR-FIRE” and civil air defense doors to “A-DOOR-PADF.” Since Revit lacks specific categories for these mappings, subcategories can be created within the door family and loaded into the project.

Steps:

1. Open the Family Editor and, under Object Styles, create a new subcategory named “Fire doors.” Set the line style and material as needed.
2. To avoid affecting other subcategories, filter and select only the door’s contour lines, copy them, and assign the “Fire doors” subcategory to these copied lines. Group them if necessary and align properly.
3. Load the modified door family back into the project. You will now see the “Fire doors” subcategory available for visibility control and CAD export layer mapping.

Besides subcategories, line styles can also be used to specify CAD export layers; we will cover line style methods in future discussions.

These examples highlight two practical uses of subcategories in Revit. There may be additional applications encountered during project implementation, and we invite readers to share their experiences and suggestions.

Related Skills Search

Controlling Model Component Visibility with Revit Subcategories

xuebim

Follow the latest BIM developments in the architecture industry, explore innovative building technologies, and discover cutting-edge industry insights.

← Scan with WeChat