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.