Is there a way to select the Curtain Wall Vertical Grid - Justification parameter using Element.GetParameterValueByName ?
Thanks for any help
Oh, this IS odd. It looks like Revit API treats the “Justification” for both Vertical and Horizontal Grids as a single parameter, with integer values ranging from 0-8 for various combinations of End, Center, Beginning for each.
However, the api documentation has this:
CurtainGrid.Grid1Justification Property
The justification for the U grid line pattern of the curtain grid.
And
CurtainGrid.Grid2Justification Property
The justification for the V grid line pattern of the curtain grid.
But these do not seem to be exposed
Ok, so i wasn’t going crazy 
“Name” isn’t too safe to use for selecting parameters, given situations like this and localization issues. We should select them by their BuiltInParameter name (for built-in parameters like this one), or by their GUID (for shared parameters). There’s no way other than by name to select a Project Parameter. When developing for the API, user created parameters should be shared parameters for this reason so you can be sure you have the right one.
For Curtain Grids, “Number” (the number of divisions vertically and horizontally), and “Offset” (start offset) also have the same name for Vertical and Horizontal.
Hope that helps,
I’ve added an issue to Github for this. https://github.com/DynamoDS/Dynamo/issues/2530
Zach Kron
I want to control the gradual change in the curtain wall mullions (size, width), how to do?
Hey Zach,
Was there any update on this? I’m trying to shift the mullion pattern or curtain grid patterns via dynamo of a planar wall. Is there a way to do this? this is my start
I mean, is there even any way to write a curtain wall from Dynamo geometry? Or even Revit mullion elements from Dynamo curves? It’s easy to write adaptive curtain panels or use adaptive families to define mullions but to write them to Revit together as a curtain wall with proper mullion-to-panel dependencies doesn’t seem possible.
Or I just haven’t figured it out…
Any insight or clarification appreciated.
Bump for this topic. I’m interested in the initial question (except for Offset rather than Justification). I’ve found that I can write to the offset parameter, the problem is I don’t know whether it will be horizontal or vertical. Is there a way to specify which one?
For instance, there has to be a way to drive the horizontal mullion grids by the levels of the project. Does anyone know of a way to do this?
Bump for an old topic. I too am trying to to right to the curtain grid offset parameter. I have curtain wall nested inside of another curtainwall, it is the nested version i am trying to write to. I think what i have should work, but i’m getting a error with set built.in parameter. Any ideas? Thanks!
Hey Christopher, make the hostPanels a list before connecting to the SetBuiltin Parameter Elements.
same for Parameter Values. inputs should be lists
Thanks guys, that worked!