(1) Except as provided in Sentences (2) and (3), exterior columns and posts shall be anchored to resist uplift and lateral movement.
(2) Except as provided in Sentence (3), where columns or posts support balconies, decks, verandas and other exterior platforms, and the columns or posts extend not more than 600 mm above finished ground level, the supported joists or beams shall be,
(a) anchored to a foundation to resist uplift and lateral movement, or
(b) directly anchored to the ground to resist uplift.
(3) Anchorage is not required for platforms described in Sentence (2) that,
(a) are not more than 1 storey,
(b) are not more than 55 m² in area,
(c) do not support a roof, and
(d) are not attached to another structure, unless it can be demonstrated that differential movement will not adversely affect the performance of that structure.