I recently read a fellow bloggers method for scheduling the area of a filled region, and since I tend to be lazy about these things...I started to wonder if there was another way which required less work on my part...so here is my solution.
This solution uses the IMAGINiT Revit Utilities Parameter Copy tool...there may be others that can do something similar, but since this is the one I have, I am using this in my example.
First I created a schedule of Detail Items and added an area parameter that I can copy the unschedulable area parameter into my parameter.
If you go to the Parameter Copy tool, you will want to select Detail Items for the Category, then select Next.
Next select the parameter to Copy From, then To, select Next.
The tool will show a dialog indicating how many it copied, select OK to close.
Now when you look at your schedule you will see the updated fields
If you modify the size of the filled regions or add new ones you will need to run the tool again because this will not automatically update.