How to Combine Families in Revit (Nesting)

You combine families in Revit primarily by nesting one or more families inside a host family. This method allows you to build complex components using simpler, reusable family parts.

The process of "combining" families in this way is known as nesting. It's a fundamental technique for creating detailed and flexible family content in Revit.

How to Nest Families in Revit

According to the standard method for nesting families in another family, you follow these key steps:

1. Create or Open a Host Family: Begin by creating a new family or opening an existing family file (the .rfa file). This will serve as the container or "host" for the families you want to combine. The reference notes that "The host family can be a new family of an existing family."
2. Load Families to Nest: Go to the Insert tab in the Revit Family Editor, then click Load Family. Navigate to and select the .rfa files of the families you wish to nest inside your host family. Click Open to load them.
3. Insert Instances: With the families loaded into your host environment, you can now place instances of them. Still on the Create tab (or Architecture/Structure tab in a project, but you're in the Family Editor here), click Component. From the Type Selector dropdown, choose the family type you just loaded and place it in your host family's view (e.g., floor plan, elevation, or 3D view). As the reference states, you "load and insert instances of one or more family types into it." You can insert multiple instances of the same family or instances of different loaded families.

Why Nest Families?

Nesting offers several advantages:

• Creating Complex Components: Build detailed objects (like a table with chairs, a light fixture with a junction box, or a door with hardware) by combining simpler families.
• Parametric Control: You can associate parameters from the nested families with parameters in the host family, allowing control over nested components from the host level.
• Visibility Control: Control the visibility of nested components within the host family, allowing parts to be hidden or shown based on view settings or parameters.
• Reusability: Standard components (like bolts, handles, or light bulbs) can be created as simple families and nested into multiple host families, promoting consistency and saving time.

Think of it like building with LEGOs – each LEGO brick is a simple family, and you combine them to build a complex model (the host family).

Step	Action	Purpose
1. Prepare Host	Create or open the primary family (.rfa) where nesting will occur.	Provides the container for combined elements.
2. Load Components	Use Load Family to bring other .rfa files into the host.	Makes the families available for insertion.
3. Place Instances	Insert instances of the loaded families within the host environment.	Physically combines the family geometry/elements.

By following these steps, you effectively "combine" families by building a hierarchical structure where smaller, nested families are components of a larger host family.