Schedule mutual (unexposed) surface area

[qingdom]

Hi,

I know i can schedule the exposed surface but is it possible in Archicad to schedule an unexposed surface area between two building materials?

In my example this is a complex wall and i need the area between the insulation and the concrete footing (the green line shown in the red rectangle).

Or can i only schedule the left side of the insulation and not the sides?

Thanks