How do you create a label parameter in Revit?

A label parameter in Revit is primarily created within the Family Editor to display dynamic textual information, making your drawings smarter and more efficient. This is particularly useful for elements like title blocks, annotation families, and tags that need to reflect varying data.

Understanding Label Parameters in Revit

Label parameters are placeholders that display data associated with a Revit element or the project itself. Instead of static text, a label parameter pulls its value directly from a corresponding parameter in the project or an instance of the family. This ensures consistency and automates updates, as changes to the source parameter are automatically reflected in all associated labels.

Step-by-Step Guide to Creating a Label Parameter in the Family Editor

Creating a label parameter in Revit typically involves working within the Family Editor, especially when customizing elements like title blocks or annotation symbols.

1. Accessing the Family Editor

First, you need to open the family where you want to create the label. This could be a title block (e.g., a .rfa file for a sheet format) or an annotation family.

To open an existing family: Go to File > Open > Family.
To edit a family already in a project: Select the family instance in the project, then click Edit Family in the Ribbon.

2. Initiating the Label Creation

Once inside the Family Editor:

On the Family Editor's Create tab (or Design bar in older versions), locate the Text panel.
Click the Label command.

3. Placing the Label

Click the location on the sheet or in the family view where you want the label to appear. This will open the Select Parameter dialog box.

4. Adding a New Parameter

In the Select Parameter dialog box, you'll see a list of available parameters. If the parameter you need doesn't exist, you'll create a new one:

Click the Add button. This will open the Parameter Properties dialog box.

5. Defining Parameter Properties

The Parameter Properties dialog is where you configure the details of your new parameter. This is a crucial step for making your label functional.

Choose Parameter Type:
- Family Parameter: This parameter will only exist within this specific family. It's suitable for internal family logic or data that doesn't need to be shared or scheduled externally.
- Shared Parameter: This is highly recommended for label parameters that need to be consistently tagged, scheduled, or used across multiple families and projects. Shared parameters are defined in an external .txt file, ensuring their definitions are uniform.
  - If you select Shared Parameter, you must then click Select.
    - Browse to your shared parameter file (.txt).
    - Choose an existing parameter from the file, or click Edit to create a new shared parameter definition within your file.
    - For more on shared parameters, refer to Autodesk's documentation on Creating Shared Parameters.
Parameter Data:
- Name: Give your parameter a clear and descriptive name (e.g., "Sheet Number," "Project Name").
- Discipline: Select the relevant discipline (e.g., Common, Architectural).
- Type of Parameter: Choose the data type (e.g., Text, Integer, Length, Area).
- Group parameter under: This determines where the parameter appears in the Properties palette (e.g., "Identity Data," "Dimensions").
- Instance / Type:
  - Instance: The parameter value can vary for each instance of the family. Ideal for unique information like sheet numbers.
  - Type: The parameter value is the same for all instances of that family type. Useful for properties common to a family type.

6. Finalizing the Label

After defining your parameter:

Click OK in the Parameter Properties dialog.
The new parameter will now appear in the Select Parameter dialog.
Select your newly created parameter from the list and use the green arrow to add it to the Label Parameters box on the right.
You can add multiple parameters to a single label and also add sample values to see how the label will look.
Click OK again. The label will now display its sample value in the Family Editor.

Types of Parameters for Labels: Family vs. Shared

The choice between Family and Shared parameters is crucial for labels, impacting how data is managed and utilized across your projects.

Feature	Family Parameters	Shared Parameters
Scope	Internal to the specific family	Can be used across multiple families, projects, and even linked models
Tagging	Cannot be tagged by generic tags in a project	Can be tagged and scheduled in projects, ensuring consistency
Scheduling	Cannot be scheduled in projects	Can be included in project schedules
File Location	Stored within the `.rfa` family file	Stored in an external `.txt` file, managed centrally
Best Use Case	For data unique to a single family, not needed elsewhere	For data that needs to be consistent, taggable, or schedulable across projects

Practical Applications and Best Practices

Label parameters enhance project data management and drawing production.

Common Applications:

Title Blocks: Displaying dynamic project information such as:
- Project Number (Project Information parameters)
- Sheet Name, Sheet Number (Sheet parameters)
- Revision Data (Revision on Sheet parameters)
- Drawn By, Checked By (Project Information or custom shared parameters)
Annotation Families (Tags): Creating custom tags that display specific element properties, for example:
- Room name tags
- Door number tags
- Equipment tags

Best Practices:

Utilize Shared Parameters for Project-Wide Data: For any information that needs to be consistent across multiple families, schedulable, or taggable, always use shared parameters. This is fundamental for robust BIM workflows.
Name Parameters Clearly: Use descriptive and consistent naming conventions for your parameters.
Consider Parameter Grouping: Group parameters logically (e.g., under "Identity Data," "Graphics") to make them easy to find in the Properties palette.
Test Thoroughly: After creating a label parameter in a family, load it into a test project and ensure it displays the correct information as expected.

Troubleshooting Common Issues

Label Not Displaying Data:
- Ensure the corresponding project or element parameter has a value.
- Verify the parameter type in the label matches the data type of the source parameter.
- If it's a shared parameter, ensure the shared parameter definition in the family matches the one used in the project.
Parameter Not Showing Up in Properties Palette:
- Check if it's an instance or type parameter, and if you're looking at the correct level (instance properties vs. type properties).
- Verify the "Group parameter under" setting in the parameter properties.