This is what you have to do to create your own wall as lets say a composite.
First make your own 'Fill type' for your elevation view.
After that create a new surface with your own image as 'texture' and your new fill as 'vectorial hatching'.
Then create a 'Building material' with your fill and surface.
At last make a 'Composite' with your 'Building material'.
Architectural construction designer, draftsman, modeller
ArchiCAD 25.