Some code requirements measure cover to the main reinforcement instead of the clear distance to the first rebar element. For this requirement stirrup and tie rebar can attach to the exterior side of rebar cover reference.
 Structural Rebar
 Structural Rebar  (Rebar Shape).
 (Rebar Shape). 
		   Properties panel
 Properties panel  
 
			  (Family Types).
 (Family Types). 
		  