Area of surface?

[Kamelite]

So, this is the problem: In a composite wall, depending on the position of the reference line, the wall area measures incorrect when I do ITO's in Solibri 9.9. compared to Archicads own ITO's.

Depending on where the reference is placed to get a somewhat correct area is not a good solution!

Is it a way to calculate the area of (any composite object) a wall in this case, based on the skin-definitions (finish, core, other), combined with whether it is outside or inside, to ensure a somewhat reliable result?

.Kamelite

[Podolsky]

It is possible to calculate volume of Building Material. Knowing thickness of the skin you can get area of different skins. It also depends - what is material. If it's brick or concrete block - it is possible to calculate amount of bricks / blocks from the volume. If it's concrete - then just volume is needed.
ArchiCAD also can calculate Surface Area - that is very precise. From these numbers you can get areas for painting and finish skin - like plasterboard, OSB or plywood.