This is more of an observation of Revit behaviour rather than a tip, but it may be a useful thing to know.
When you have created dimension strings and the elements dimensioned are no longer visible, the dimensions try to adjust accordingly (in some cases).
If I turn the Visibility of the windows off, the dimension string remains but hides the dimensions that relate to the window. The dimensions string can still be selected as one element.
When the windows are turned back on the dimensions will reappear.
If you adjust the View Range of the view, to a range where the doors and windows are no longer visible (moving the cut plane above the head height of the elements). The dimension string still remains intact and visible, even though the doors and windows are no longer visible in the view.