When an element is no longer associated with a work plane, the element is free to move irrespective of a work plane.
On the Properties palette, the dissociated element's Work Plane parameter value is <not associated>.
Examples of work plane-based elements include solid geometry in the Family Editor and extruded roofs in a project.
To dissociate an element from a work plane
 (Dissociate Work Plane), which displays in the drawing area near the selected element.
 (Dissociate Work Plane), which displays in the drawing area near the selected element. 
	  Work Plane panel
Work Plane panel
 (Edit Work Plane).
 (Edit Work Plane). 
		  If the Dissociate button displays as gray, the element is not currently associated with a work plane, or it is not a work plane-based element. (For example, it may be a face-based element.)
To reassociate an element with a work plane, use the Edit Work Plane tool to specify a new work plane.