Use a Wall tool to create a non-bearing wall or a structural wall in the building model.
Non-bearing walls: Click 
		
 (Wall: Architectural) on the 
	 
Build panel
Wall drop-down 
		
Structure panel
Wall drop-down 
		Structural walls: Click 
		
 (Wall: Structural) on the 
	 
Build panel
Wall drop-down 
		
Structure panel
Wall drop-down 
		