AS 1657:2018 — Fixed platforms, walkways, stairways and ladders: Design, construction and installation — is the current edition of the Australian Standard that governs permanent means of access at height. It applies to roof walkways, maintenance platforms, access stairs, step-type and rung-type ladders, landings, guardrailing and handrailing.
It is a design and construction standard, not a work method standard. It tells you how tall the guardrail must be, how steep a stair may be, how wide a walkway must be, and when a ladder needs a landing — but it does not tell you how a worker should behave once they are up there.
Guardrailing is required wherever a person could fall more than a defined threshold near an edge or opening, with minimum height and mid-rail or infill requirements. Walkways have minimum clear widths and must be level, slip-resistant and free of trip hazards. Stairs sit within defined pitch ranges with compliant goings and risers; anything steeper falls into step-ladder or rung-ladder territory, each with its own rules.
Ladders above a certain height need landings at set intervals, and landings need self-closing gates at ladder access points. Toe boards are required where dropped objects are a risk. Every one of these is a drawing-stage decision — none of them can be fixed cheaply once the steel is on the roof.
The standard also sets loading requirements for platforms and guardrail, and dimensional rules for clearances around ladders and landings. When a specification just says 'access to AS 1657' with no detail, it is delegating every one of these decisions to the installer's best guess.
Most access failures are not installation failures. They are specification failures that no one caught until the building was finished and someone had to get onto the roof.
Before a package goes out, an access specification should answer: who will need to get up there, how often, what will they carry, what will they do when they arrive, how do they get back down, and how does an injured person get rescued (rope access) .
Access shown on drawings but never priced, so it disappears at value-engineering stage. Ladders that terminate without a compliant landing or self-closing gate. Guardrail called up in principle but with no detail at penetrations, corners or level changes.
Walkways specified to reach the plant but not the parts of the plant that need servicing. Fragile roof material with no marking or protection. Anchor points nominated with no rescue plan (rope access), no load path back to structure, and no clear documentation.
Compliance does not stop at practical completion. Installed systems need certification, an as-built register, user instructions and a recertification schedule.
If the access system cannot be shown to be compliant on paper, the building owner carries the risk — so the documentation is as much a part of the deliverable as the steel.