Safety from Falling

The document setting out the requirements for safety from falling is the New Zealand building code F4. This document sets out the definitions, barrier heights, barrier construction and maximum sizes of openings in both horizontal and vertical directions of the barrier. As decks are frequented by children under the of 6 years old, these are considered in the requirements to prevent children climbing up the handrail.

The document shows various barrier arrangements diagrams with all of them a maximum horizontal opening of 100mm. Vertical openings of up to 100mm are permissible, but only at the top and bottom of the barrier. Meshed designs are also can also used but these have a maximum opening of 35mm or 50mm diagonally.

With steps, its possible a triangle sized gap may be present at the bottom of a barrier. The requirements are that this gap cannot be big enough for a Ø150 sphere to pass through.

For more details you can download the building code here