Even when you do not understand the concept behind Revit families, it is safe to say you have been using them in your modelling process in Revit. A Revit family shares the same functions and behaviours as well as an overall look, though each type in the family may have slight variations. Autodesk states that all elements in Revit are in defined hierarchies and are parts of a family. Now, it’s time to define what a family in Revit is.

We cannot edit the Rectangular Column family but we can modify each type in this family. The types in this family include 300mm x 300mm rectangular columns and 600mm x 600mm rectangular columns (they may be many more types in the software). We want rectangular columns which are actually part of an uneditable system family (more about this below). Say, we want to add columns to the structure. A family can consist of more than one type, a set of values that can conveniently switch many variables of a family at once. The difference between a category and a family is that the definition of a family is less broad, i.e. Just like how all elements are part of a Category, they also belong to a defined family. To define elements and their behaviours better, we have the next level in the hierarchy – Families. The Categories are manifested in all shapes, sizes and behaviours. On the other hand, Annotation Categories are dimensions, tags, and texts. The elements in the Model Categories include elements of your model like doors, windows, beams, and walls. The most common categories a Revit user will encounter are the model and annotation categories. The first level of hierarchy is the Categories, pre-defined and uneditable. Before we dive into a definition of the Revit family, we should first understand the hierarchy in a Revit model.