Specify the floor plans or ceiling plans used for calculation for each level of the Project.
Definable calculation views are necessary for multiple views that represent a single level in Revit. You must define the view that will generate Areabook data.
The Calculation Settings dialog displays.
A list of the existing levels displays with the corresponding views Areabook uses for calculation.
Definable calculation views are necessary for the Revit tools to duplicate views. This allows different views for a single level. In this case, you must define in which view to generate Areabook data. It is not suggested to have multiple instances of Areabook data in different views.