A balustrade has one main job: to stop people falling. That is why balustrades and handrails in Australia are covered by the National Construction Code (NCC), which sets out clear rules for height, gaps and design.
Whether you are building a new deck, renovating a staircase or managing an apartment building, understanding these rules will help you plan a design that looks great and passes inspection.
This guide is a plain-English summary of the main NCC requirements. Your certifier or builder will confirm exactly what applies to your project.
When do you need a balustrade?
Under the NCC, a barrier is required anywhere it is possible to fall 1 metre or more. This includes:
- Decks, balconies and verandahs
- Stairs and ramps
- Landings and mezzanines
- Raised paths and retaining walls next to walkways
The fall height is measured from the floor or walking surface down to the surface below, not from the top of the balustrade.
Minimum balustrade height
- Decks, balconies, landings and floors: at least 1 metre above the floor
- Stairs and ramps: at least 865 millimetres above the stair nosings
These are minimums. Some designs use a higher balustrade for extra privacy or wind protection, particularly on upper floor balconies.
The 125 mm gap rule
Openings in a balustrade must not allow a 125 millimetre sphere to pass through. This applies to the gaps between balusters, wires, glass panels and the space at the bottom of the barrier.
The rule exists to stop young children slipping through or becoming stuck. It is one of the most common reasons older balustrades fail an inspection.
Where a balustrade is fixed to the face of a deck or slab, the gap between the barrier and the edge must not exceed 40 millimetres.
Climbability: the 150 mm to 760 mm zone
Where the fall is more than 4 metres, the NCC adds another rule. Any horizontal element between 150 millimetres and 760 millimetres above the floor must not make the balustrade easy to climb.
In practice, this means no mid-rails, ledges or horizontal footholds in that zone on upper level balconies and high decks. It is also why horizontal wire balustrades need careful thought on second storey projects.
Vertical balusters, frameless glass and semi-frameless glass are popular choices for higher balconies because they avoid this issue.
Wire balustrades
Wire balustrades can comply with the NCC, but only when built to strict specifications. The wire diameter, spacing, post spacing and tension all need to be correct so the wires cannot be spread apart beyond the allowed gap.
Wire loses tension over time, so regular checks and re-tensioning are important. Our earlier article on choosing between glass and wire balustrades covers the pros and cons in more detail.
Glass balustrades
Glass used in balustrades must comply with Australian Standard AS 1288, which requires Grade A safety glass. The glass type, thickness and fixing method all depend on the design and the loads the balustrade needs to carry. If you are fencing a pool, see our guide to installing glass pool fencing to Australian Standards.
All balustrades, whatever the material, must also be designed to handle the loads set out in AS/NZS 1170.1. A balustrade needs to hold firm when someone leans on it or a crowd presses against it.
What about handrails?
On stairs, handrails are generally required at a height of at least 865 millimetres above the stair nosings. They need to be continuous and easy to grip so people can steady themselves along the full flight.
Commercial and public buildings often have extra accessibility requirements under AS 1428.1. These cover handrail height, profile and extensions at the top and bottom of stairs and ramps. We can help you work through these on commercial projects.
Do older balustrades need to be upgraded?
Many homes and apartment buildings in Newcastle were built before the current rules came in. Some have balustrades that are too low, have wide gaps or include horizontal rails that children can climb.
For strata buildings in NSW, this is more than a design issue. In Doherty v Strata Plan No. 36613 (2021), the NSW Civil and Administrative Tribunal Appeal Panel found that an owners corporation had a duty to upgrade a balustrade to meet current requirements, even though it may have complied when it was first built.
If you manage or live in an older building, it is worth having your balustrades reviewed. The owners corporation should get its own legal and building advice on its obligations.
A quick compliance checklist
- Is the fall 1 metre or more? You need a barrier.
- Is the balustrade at least 1 metre high on decks and balconies, or 865 millimetres on stairs?
- Would a 125 millimetre sphere fit through any gap?
- Is the fall more than 4 metres? Check the 150 to 760 millimetre climbable zone.
- Is any glass Grade A safety glass to AS 1288?
- Are wires tensioned and spaced correctly?
Designed to comply, built to last
At Contemporary Stainless Solutions, we design, fabricate and install stainless steel, aluminium and glass balustrades and handrails for homes, strata buildings and commercial projects across Newcastle, Lake Macquarie and the Hunter Valley.
We build every balustrade with the NCC in mind, so you get a finish that suits your home and meets the rules.
Planning a new deck or upgrading an older balustrade? Contact us today for advice or a free quote.
This article is a general guide only and is based on the NCC as at October 2026. Requirements can vary depending on your project, so always confirm details with your certifier.
Recent Comments