curtain wall area tags

[j_starko]

I'm haing troubles creating a tag family which will show the area of a curtain wall panel system . You can see the area when you're looking the element properties, I'm just struggling with how I can make a tag show this data.

Any pointers ?

I've modified my windows family to have a parameter for window area, but I'm not sure that a curtain wall family can be made to do the same thing.