How to Use Legend Expressions When Creating Families in Revit
What are the key expressions when using Revit legends? Common examples include architectural door and window schedules, door opening directions, mechanical and electrical equipment, and valve legends. So, how can you create accurate legend expressions within Revit families? Generally, there are two main approaches:
Method 1: Draw directly on the family’s plan and elevation views using lines, text, and fill tools.
This method is widely used and is especially suitable for representing 3D models in plan or elevation views. It generally meets Revit’s legend requirements by adding a few lines to fulfill the necessary legend expressions.
However, this approach has some drawbacks. First, it does not support the direct use of Fill Areas, which means alternative functions must be used to simulate filled effects. Second, improper use of model and detail lines can lead to cluttered linework in the 3D model. Additionally, controlling parameters for some 2D lines can become confusing due to excessive reference inputs when creating 3D families. Finally, if you need to annotate scale effects, simply adding 2D lines may not produce the desired results.
Method 2: Use Metric Detail Components or Generic Annotations to create drawing legend representations for families, then display them as nested families within plan or elevation views.
Personally, I recommend this method—especially for families that require clear flat legends, such as electromechanical valve components or angled plane legends. By using either Metric Detail Components or Generic Annotations, you can apply various 2D family tools effectively, including text, labels, symbol lines, fills, and masks.
After completing the drawing, keep the following points in mind:
- Understand the reference level well to facilitate nesting into 3D families and ensure correct reference locking settings.
- When nesting into the 3D family, map the parameters correctly for seamless parameter linkage.
- Select Metric Detail Components for nested legend families created from this template. These do not have annotation scales and are typically used for 3D families with true-scale dimensions—for example, legends showing the opening direction of air duct valves or doors and windows in double-line diagrams.
- Select Generic Annotations for nested legend families with annotation scales. These may zoom in or out depending on the view’s scale, so consider scale factors carefully when defining legend sizes. Legends with annotation scales are usually applied in 3D families such as pipeline valves and accessories shown in single-line diagrams.
- When adjusting visibility in Revit, be careful not to accidentally turn off the visibility of Metric Detail Components or Generic Annotations. Turning off their visibility can cause legends to disappear from floor plans. Although these nested families reside within the 3D family, they are still classified as Metric Detail Components or Generic Annotations once loaded into the Revit project model.
Related Skills
Legend Text in Revit 3D Model Families
Must log in before commenting!
Sign Up