ok... here's the thing: I need to insert an opening in a wall, but just in an option 2. When I try to insert it in the wall, which is in the main model, i get the message that I can't. If I cut the wall from the main model, and paste it in op1 and op2, for inserting the opening in op2, when I view the EXISTING plan, obviously the wall isn't there. How does I have to do that?? any idea?