Revit Families – Introduction

Revit Family creation can be part of the Building Information Modelling (BIM) life cycle.

Revit Family are an incredible feature. Components that are developed during the process of creating a difital model known as ‘BIM components’. Since Revit is one of the most popularly used software in BIM modelling, they are sometimes known as ‘Revit Families‘.

This article looks at the Revit Family Definition, Revit Family Typologies (System Families, Loadable Families and In-place Families) and the Element Revit Hierarchy.

Revit Family Definition

Basic concepts and terminology;

All elements in the Revit platform are part of a Revit Family and they fit into a clearly defined hierarchy. At the top level of this hierarchy, are Categories. Categories are pre-defined within the software and cannot be added, deleted or renamed. A wide variety of categories are included in Revit and distributed among a few overall master groups including: model and annotation (but there are a few others). Model Categories include all elements that comprise your building model such as: Walls, Doors, Floors, Stairs and Beams. Annotation categories include items like Text, Dimensions and Tags. Categories are by definition very broad. It would not be enough to simply have a Walls or Doors category. These items come in all shapes, sizes and behaviors. Therefore, the next level of the hierarchy is the Family. All Revit elements belong to a family. Families are best thought of simply as a collection of like items sharing the same overall look and behavior. Revit includes many families such as the “Basic Wall” wall family, the “Single-Flush” door family and many annotation families like “Text” or “Linear Dimension Style.” Even the views themselves like floor plans and sections are system families in Revit.

Revit Family Typologies

Families branch into two major kinds based on their behavior: the System Family and the Component (Loadable) Family. System families include anything that is built into the software and cannot be manipulated by the user in the interface. This can include model components like walls and floors, but also includes equally important items like floor plans, project data, and levels. System families cannot be created or deleted. Their properties are pre-defined at the “factory.” However, most system families like walls, floors and roofs can have more than one: Type. A type is our next level or hierarchy in Revit. Think of it as a collection of variables (sizes, materials or other settings) saved to certain values and given a name for ease of reuse. A Type provides a convenient way to switch several variables of a family at once. A family can contain one or more types; each with its own unique user-editable settings. So while for example we cannot create or delete wall families, we can add, delete and edit the types associated with each of the provided wall families. For example, “Basic Wall” is the most common wall family. In the out-of-the-box template files, there are several predefined Basic Wall types such as: Exterior — Brick on CMU, Generic 6″ and Interior — 5 ½″ Partition (1hr). The Basic Wall definition simply means that it is a layered wall that has the same structure along its entire length and height. The actual make-up of this structure can vary widely from type to type as the names noted here imply.