Revit.Element.Parameter value: how to fake?


there is the Parameter.Value node that I us to extract some lengths from selected elements.

However, in the list I am passing to the node there are some null values (the parameter is missing in those families).

Is there a way to replace those null values with a 0’-0" Revit.element.Parameter type of data?

In other words, I need to trick Revit into accepting a zero length value but its format needs to be compatible with the node “Parameter.Value”… I am pretty sure there must be a way in Design Script to create such a value and pass it on to a ReplaceNull node… ?

Hope this is clear enough,

Thank you




Hi @Giovanni_Succi,

You could do an If Statement like this :


Or use a ReplaceNull node :


Thank you Alban,

The issue was about the node “Parameter.Value” which requires a “Revit.Elements.Parameter” data type.

My list had Empty List and the node was not able to process them, hence the idea of replacing the empty lists with some data compatible with the node.

Instead, I realized that there was another node, “Element.GetParameterValueByName” which returns directly the value of the parameter and is compatible with empty data… so I ditched “Parameter.Value” altogether.


Thank you




If you were curious as to what pairs up with this node.