When you create a mass family in the Family Editor, you can then load the family into a project, and place instances of the mass family in the project.

- Click File tab
New
Conceptual Mass.
- In the New Conceptual Mass dialog, select Mass.rft, and click Open.
The file is located in this folder:
%ALLUSERSPROFILE%\Autodesk\RVT 2026\Family Templates\<language and locale>\Conceptual Mass
The conceptual design environment opens. Use the Forms tool and other tools to create the mass.