I've just created a window family with a brick sill. In order for the sill to be partially embedded in the wall (external face) I had to create two Voids, one that went all the way through the wall for the glazing and frame and the other partially through the wall to contain my sill (a solid sweep).
Is this the best way to do this? I couldn't do a combination of Opening and Void so I guess I had no choice really. Has anyone else got another method, or is there any reason why you wouldn't use Voids all the time instead of Openings?