Which version are you using? The answer could depend on your version. You might want to enter these data into your Signature.
So, I suppose you are talking about the automatically generated 2D Previews of Doors/Windows in Schedule Cells. The answer is No, enclosing Walls cannot be generated as part of these preview, you will have to open the given Schedule Cell by clicking the Annotate button in its top left corner, and draw the Wall 2D using Lines and Fills.
Prior to AC20, the Background of Fills are controlled by Model View Options (set Fill Override for Cover Fills to "No Fill" or Override Fill Background Colors to "Transparent Background") or from AC20 Fills in Schedule Cells can be hidden by defining and applying Graphic Overrides.
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