Can you attach some examples of what you wish to create?
You can assign hatches to walls by style in the attributes tab, in the wall styles dialog. You can create different wall styles for demolition and reconstruction, and assign them different hatch colors.
Yes for reconstruction you can hatch a new wall style.
But for demolition, i think the best is to do a 2d section plan of the object, so it appears on the plan, but not in the 3d model.