Modify Built in Parameter of Window glass heat transfer coefficient using python

Revit
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1

Dear Network,
I am trying to set heat transfer coefficient (I assumed this is a built in parameter named - —ANALYTICAL_HEAT_TRANSFER_COEFFICIENT) of window glass using following python command,

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But this results following error in python node .
Warning: AttributeError : ‘NoneType’ object has no attribute ‘Set’ [’ File “”, line 32, in \n’]

your help is appreciated!

2 
#Built In parameters cannot be looked up like that.
p = i.get_Parameter(BuiltInParameter."ANALYTICAL_HEAT_TRANSFER_COEFFICIENT")

#No need here for the "ElementId" as that isn't the type of value stored
p.Set(3.5)
1 Like
3

Hi,
Thank you very much for your prompt reply. I modified my code accordingly. Now python code do not output any errors, yet the properties are not updated in the Window Family Type.

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Do you find any error in the code?

From Revit Look up tool the parameter can be identified as “Not ReadOnly”

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4

Are you using Types or Instances? The reason I ask is because the type parameters clearly show a value, but then Lookup shoes it’s 0. So, not sure if they are the same parameters.

Alternative:

i.LookupParameter("Heat Transfer Coefficient (U)").Set(3.5)

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5

Thank you for the response. Well, alternative method proposed works well.

I think I have misunderstood changing of Revit parameters. This link ( Built-In Parameters - Dynamo Python Primer (gitbook.io)) helped me to understand a bit about parameters and classes in revit.

Actually I am trying to extract data from Type level and IN[0] is connected to All elements of category node which gives outputs at Instance Level . Then I had to go downstream with following code modification.

for i in UnwrapElement(elements):
family_type_id = i.GetTypeId()
family_type = doc.GetElement(family_type_id)

1 Like