Technical Booklet V Glazing·Page 14·2.7
Permanent screen protection requirements
When glazing in a critical location is protected by a permanent screen, the screen must prevent a 75 mm sphere from touching the glazing, withstand a horizontal force of 0.36 kN at 800 mm height, and if guarding is required under Part H, be designed so children cannot readily climb it.
When glazing in a critical location is installed behind permanent screen protection the screen should –
(a) prevent a sphere of 75 mm diameter from coming into contact with the glazing;
(b) be capable of withstanding a horizontal force of 0.36 kN at a height of 800 mm above the floor level applied at any point along its length; and
(c) when glazing forms part of guarding required by Part H, be constructed so that a child cannot readily climb up it.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet V - Glazing.pdf