Monday, August 17, 2015

Instance vs Type Parameters

Difference between Instance Parameters and Type Parameters Explained
(Explanation of Shared Parameters Included)

            Have you started working with Revit families and wondered when making parameters what all the different options really do? Well here is a straightforward explanation with some useful images.

Note: I will not be covering how I made these families or the proper techniques for applying parameters to families. A couple great resources for this however are Lynda.com, specifically “Revit Architecture: The Family Editor”, the Revit Help Bar, or many different videos on YouTube about the subject.

·        Instance Parameters
o   After clicking the Family Types button while editing a family (upper left button in the “Create” Tab that looks like this…(Image 2)



o   The popup (image 1) appears, and then once you click “Add” under Parameters on the right side, the front tab of image 1 comes up. Here you have the option to select the Parameter Type and Parameter Data.
o   If you select Instance, then that parameter you have created will only apply to an “Instance” of the placed family (only one). This means you can change this parameter in another “instance” of family without it affecting the original family.
o   The other grand thing about Instance parameters is that they appear and can be edited inside the Properties Tab in your project.
§  This means no having to open the family to edit the parameter, it is available immediately!

o   The highlighted parameters are Instance Parameters I created inside HarveysShower Family. Now I can change these parameters inside my project without the original family changing.
§  However, whatever is input into those parameters inside the family is the “Default”, meaning that when the family type is placed, those are the original parameters it will have.

o   And voila! I input the new size of my HarveysShower (Family Type:) HPH 36” x 60”, and it is now 7’ Deep and 10’ Wide in this instance. Now if I placed a new instance of that family using the Component tool, Dragging out of the project browser, or a different family insert tool, that HarveysShower HPH 36” x 60” would be the same as image 3, as that is the “Default”.

o   Instance Parameters are great for items that change parameters (size, text, or otherwise) a lot and need to be edited in almost every instance.

·        Type Parameters
o   Type parameters are parameters that hold true for every instance of that Family Type. This means when you place multiple families and edit instance parameters, the type parameters are not edited.


o   The highlighted parameters are type based. This means when you a place an instance of a Family Type, these are always consistent of the Type.
o   Type parameters are very useful to keep families clean and problem free in the project (as editing some parameters in certain ways “destroy” the geometry of a Family), and are best used when using multiple Family Types (Type Catologues). Making this involves clicking New… under Family Types in the Family Types pop up (as seen above). This way you can have a family with multiple options for Type Parameters. These options will be available inside the project when you are placing components…

o   As you can see, the multiple types of the HarveysShower Family I have created are visible on the left under the Properties Drop down.


o   Type Parameters and Family Types can be useful as they can fill in schedules for you later on (instance based parameters also fill in schedules, but often have to be retyped to change things, where type families can be organized to include all information for specific types of a Kohler Bathtub for example).

(If there is any incorrect information or information that pertains to the subject that should be added, feel free to comment and let us know!)

No comments:

Post a Comment