Balustrade rules in NSW, in plain English.

A balustrade is a safety barrier first and a design feature second. In New South Wales the rules come from the National Construction Code (NCC), and getting them right is what stands between a job that passes certification and one that has to be pulled off and redone. Here is the short version. Treat it as a guide, not a ruling on your specific build.

When you actually need one

A barrier is generally required wherever a person could fall more than one metre: balconies, decks, landings, stairs, ramps, mezzanines and the edge of a raised floor. Below that height it usually is not mandatory, though it is often still a good idea.

How high it has to be

For floors, balconies and decks, the barrier is generally a minimum of one metre high. For the sloped part of a stair or ramp, it can step down to about 865mm measured above the nosing line, then return to a metre on the landings. Those numbers are the common case; your certifier confirms them against your plans.

The gap and no-climb rules

Openings in a barrier that protects a fall generally cannot let a 125mm sphere through, which is what keeps the spacing between balusters tight. Where the drop is more than four metres, there is an extra rule: the design has to avoid horizontal elements between roughly 150mm and 760mm above the floor that a small child could climb like a ladder. This is why horizontal-wire and wide-rail designs need careful detailing on higher balconies.

Glass balustrades have their own standard

If the infill is glass, it also has to meet AS 1288. That means Grade A safety glass, toughened or laminated depending on where it sits and whether it must stay in place if it breaks. A frameless glass balustrade with no top rail usually needs to be laminated so a cracked panel holds together. Balustrade glass is not the same product as a shower screen, and it is specified for the load and the location.

Loads you cannot see

Behind the visible rules sit the structural ones. AS 1170 sets the loads a barrier has to resist: a person leaning, a crowd pushing, a trolley knocking into it. The fixings, the post spacing and the base plates all have to carry those loads, which is the part a good fabricator gets right and a cheap one guesses at.

The simplest way to get it right

Compliance is not the interesting part of a balustrade, but it is the part that fails an inspection. We build to the NCC, AS 1288 and AS 1170 as a matter of course and hand over the documentation a certifier or strata report will ask for. If you are not sure what your job needs, send us the plans and we will walk you through it.