When you load families into a project, the Revit imperial or metric family library (located in C:\ProgramData\Autodesk\<product and release>\Libraries\US Imperial or US Metric) is accessed by default.
If your office is using a different library of content in another location, your system may access that library by default. Contact your CAD Manager for more information.
Use the following procedure to load families. For more information about loadable families, see The Families Guide.
Load from Library panel
(Load Family). Depending on the current drawing units (imperial or metric), the Load Family dialog lists the family categories in either the Imperial or Metric Library.
The family type is now available to place in the project. It displays in the appropriate component category under Families in the Project Browser.