A balustrade is not just a design feature; it is a safety barrier, and the National Construction Code (NCC) sets minimum requirements wherever there is a fall of one metre or more. This guide summarises the main points as they apply to houses. Always confirm the details for your project with your builder or building surveyor.
When a barrier is required
Any trafficable surface — balcony, deck, landing, stair or ramp — with a potential fall of 1 metre or more to the surface below needs a barrier.
Height
- At least 1000 mm above the finished floor on balconies, decks and landings.
- At least 865 mm above the nosing line on stairs.
Openings
Gaps in the barrier must not allow a 125 mm sphere to pass through. In practice that means vertical bars set at 125 mm or less clear spacing, and glass or infill panels with the same limit at edges.
Climbability
Where the fall is more than 4 metres, the barrier must have no horizontal or near-horizontal elements between 150 mm and 760 mm above the floor that could act as footholds. This is why horizontal-wire balustrades are restricted on higher balconies and why we usually recommend vertical bars or glass there.
Strength
Barriers are designed to resist set loads applied to the top rail and infill. In steel this comes down to post size, post spacing and, most importantly, how the posts are fixed to the structure. A neat balustrade with weak fixings is not a balustrade.
How we approach it
We measure on site, confirm fall heights and fixing substrates, draw the balustrade to suit and fabricate it in-house. Powder-coated steel, stainless or a steel frame with glass infill are all options. See our balustrades page for examples.
