Wednesday, December 30, 2009

Type Catalogs

Type Catalogs are nothing new to Revit, but are something I recently dove into. So, I thought I'd share some information about Type Catalogs for those of you who may not be familiar with them.

First of all, a family type is a subdivision with a family of elements. For example, a supply diffuser family might have various face and neck size combinations (or types) defined for the family file. Each diffuser type may vary in size, but share the same parameters and have a similar graphic representation. Therefore, it is logical to group these together in one file as opposed to creating a family file for each size. There are two ways to define family types. The first is to create the family types within the family file itself. When you load this type of family into a project, all of the family types that are defined within the family are loaded. This results in many unwanted family types that become part of the project file, thus increasing the file size. The second way is to use Type Catalogs. According to the Revit MEP help glossary of terms, a Type Catalog is a "list of model elements that belong to a particular family type but that differ in size or other characteristics". Using type catalogs allows you to only load the sizes, or types, you need from a list. By only selecting the types you need, you reduce the project size and limit the number of items listed in the type selector for that family. A Type Catalog is a comma-delimited text file that defines parameter values for each family type. You can use spreadsheet or database software, such as Excel, to define family types and their parameter values to automate the process of creating the comma-delimited text file. This is a much more efficient method than defining the parameter values within the family file itself.

Below is an example of at type catalog list that will appear when you load a type catalog family:

You can sort by any parameter to help narrow down your choices. Then, simply select the family types you want to load into your project:

When you go place an instance of the family in the project, only the family types that you loaded will appear in the type selector (shown in Revit MEP 2011):

A few important things to note about type catalogs:
  • The type catalog text file that is associated with a family must have the exact same file name. For example:
      Supply Grille - Louvered - Rectangular Neck.rfa
      Supply Grille - Louvered - Rectangular Neck.txt
  • Family files and their associated Type Catalogs must be located in the same folder.
  • Instance parameters are typically not included in Type Catalogs.
I won't go into how to create a type catalog in this post. However, the Revit MEP help section has a very good explanation of how it all works and gives a good example you can use to get started.

1 comment:

  1. Great post. I think it is one of the best intros to Type Catalogs I have seen. I will be sending folks in the office here for a "plain English" definition when they ask.

    I would like to say, that we often define instance parameters through the type catalog. The catalog only sets the default value of the instance parameters, and they behave as expected a project.

    Where this is useful, is when different types have a different value for that parameter MOST of the time. This will save time when inserting the family, as you won't have to adjust that value after the family is placed for MOST situations.

    I also encourage folks to think creatively when using type catalogs. Most folks default to length and text parameters when using type catalogs, but most parameter types will work. Use 1/0 (binary) for Yes/No parameters. Family:type parameters can be controlled as long as the value is spelled exactly as the family name. See this page ( for a couple of posts from my own blog on the subject.