A. In all unenclosed areas where smoking is otherwise permitted, smoking shall nevertheless be prohibited within twenty feet from any doorway, window, opening, crack, or vent into an enclosed area in which smoking is prohibited, except while en route to another destination.

B. In all unenclosed areas where smoking is otherwise permitted, smoking shall nevertheless be prohibited within twenty feet from any unenclosed areas in which smoking is prohibited by this chapter, except while actively passing on the way to another destination.

C. The prohibitions in subsections A and B of this section shall not apply to unenclosed areas of private residential properties that are not duplexes or multifamily residences.

D. Smoking is prohibited in unenclosed areas of a duplex or multifamily unit including exclusive-use areas such as balconies, porches, decks, and patios which are within twenty feet from any doorway, window, opening, or other vent into an enclosed or unenclosed area where smoking is prohibited by this chapter or other law, or by binding agreement relating to the ownership, occupancy, or use of real property, or by designation of a person with legal control over the property.