How do you write Type Parameters? - Family Symbol node error

It seems simple - but how on earth do you write to a type parameter?

I have wall type, I want to write to its parameters. Surely this is possible.

Wading my way through possible ways to do it I came across errors in FamilySymbol.Family and Family.Symbols nodes.
They look like a coding error:


Hi there, I posted a similar question a few weeks back. Have a look here, does this help? Particularly the comment by Vikram Subbaiah;

If you want to set a type parameter you have to select wall types with an element type node. Or you can use the node from package clockwork called “element.type” then set parameters.

I also have a node in Rhythm called "SetParameterByName(TypeOrInstance) that should do the trick


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Mathew, your link is about setting an instance parameter not a type parameter.

This link has the same subject but I can’t get it to work:

This is the graph from that post.











But I get the error above in FamilyInstance.Symbol.



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Are you saying I have to select (or find) a placed instance of the type that I want to alter? i.e. select a wall that is of the wall type I want to alter.

Is there no way to just select the type and perform actions on that?

Below are a couple of approaches to set type parameters.

(Anthony - FamilyInstance.Symbol only works for loadable families like e.g. furniture. Use Clockwork’s Element.Type for system families instead…)




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Thank you Andreas, your first method works fine. I don’t know why I couldn’t get it to work. Although I do find I have to sometimes exit and restart Dynamo to get things to run properly.


Another question - is it possible to pass a line feed via a string?

There is char function but no ascii function.

You can use Shift + Enter in a Revit schedule to do it.

Not sure.

Have you tried using a string node that contains line breaks?

Another thing you could try is to include a line break command (\n) in your string.

Fantastic Andreas - takes me back to my lisp day. Works a treat.

For those not sure why, I’m writing a list of a wall’s layer materials and their thicknesses to one of walls’ type parameters so they can appear in a tag. Because the number can vary it is more convenient to write series of lines to a single parameter rather than to a series of separate parameters. (I’ve put the code in another post).







On a similar subject… Is there any way to rename a Type?

I do this a lot with BIMLink or similar (Make 1 to 50 generic types for a category, export list, let designers fill in new type names and specs for equipment, read into revit). But using Set Parameter by Name - Type Name I get the error “Parameter is read only”.

I downloaded Clockwork but i am not able to find “All family Types of Category”. Am looking for that specific function

I´m trying the Antony_Mcphee´script but I get an error. I want to chanche Family Parameters instead of Type Parameters. I’m missing something

Element.SetParameterByName needs an element and a value to work. Start a new thread and we can help you out there.

Thanks. I’ll do