[F] 903.3.1.2.1 Balconies and decks. Sprinkler protection
shall be provided for exterior balconies, decks and ground floor
patios of dwelling units where the building is of Type V construction.
705.5.2 Horizontal projecting elements. Fire walls shall
extend to the outer edge of horizontal projecting elements such as balconies, roof overhangs, canopies, marquees and similar projections that are within 4 feet (1220 mm) of the fire wall.
2006 INTERNATIONAL BUILDING CODE® COMMENTARY
in a contiguous residential structure with interior lot lines and fire walls between each dwelling unit, and where balconies (decks) are provided for each dwelling unit and these balconies are within 4 feet of the fire wall, then the fire wall must be extended to the outer edge of the balcony.