RTV Tools

Wednesday, October 3, 2012

The Mystery of Family Categories

EDIT Current category guide post:

In Revit, some families have Cut Dominance, some are Cuttable, and some respect various View Range rules in various ways.

These behaviours may further be affected by the Family Template that they were created from, whether they are Hosted or non-Hosted, whether they are Shared or not Shared.

Wouldn't it be awesome if there was a document that went through each Family Category and described its unique properties!  I have asked Autodesk for this before, but to no avail (SR# 1-9298685321 - The help file does not describe the unique properties of each Category).

Andy Milburn shares my feeling on this matter:
... I wish I know where to find a clear explanation of all these rules.  
Shades of Grey: CUT ! CUT ! CUT !

What about the Families Guide?

I may not have all the answers, but I have posted many times about the differences between certain Family Categories.  See some links below:

Cuttable vs Non-cuttable Family Category Properties

View Ranges (and TOLERANCES) Explained *REPOST*
Things like -
Walls shorter than 6 feet (approximately 1.83 meters) are not cut, even if they intersect the cut plane, and
There are a few categories for which an element located above the cut plane but partially below the top clip is shown in plan. These categories include windows, casework, and generic model. These objects are shown as viewed from above.

Project Family Category Type Instance
which Categories do not have Types, or which Category has Types but no Instances?

Making unhosted components like unhosted Doors and Windows

Create a Component Family with Category set to Walls (or other system family category)
Yes, it is possible.

Plan regions have no effect on Topography - workarounds

buildz: Wall Trimming Method
Cut Dominance in action


  1. greate post ... anyway I can't figure out how could I probably create a family that could cut topography when inserted?

  2. Luke, Interesting. Hey, I don't suppose you know of a similar source for what types of family categories allow what different parameters (shared, family, project) and can be added to what view types? The example being: I was looking to create a generic annotation family to drop on a Legend, that read the project name & number. Apparently, if you change the Category type to "Title block" you can get the project number and project name labels that you can't get when it's set to the generic category. But, you can't place such an annotation in a Legend view. I'm looking for a workaround and I came across your post and thought you might know a source.