Three words decide whether your Working at Heights work is safe and legal in Ireland: avoid, prevent, minimise. The HSA expects to see them in your risk assessment, your method statement and your training. Here is what they actually mean on a real site.
The hierarchy in 30 seconds
- Avoid the work at height entirely.
- If you cannot avoid it, prevent the fall.
- If you cannot prevent it, minimise the consequences of a fall.
You only move down the list when the level above is genuinely impossible. The HSA test is: "could a reasonable employer have done the higher-level control" - and they ask it in retrospect, after an incident.
1. Avoid - the level most companies skip
Avoid means the work does not happen at height at all. Examples:
- Long-handled paint roller instead of a stepladder
- Telescopic lance for window cleaning to first floor
- Pre-fabricated rooflights installed at ground level then craned up as a unit
- Ground-level controls on signage and lighting (drop-down systems)
- Robotic gutter inspection drones
For about 30% of historically "at height" Irish tasks, avoid is now the cheapest option. The HSA loves seeing avoid in your assessment because it is the cleanest defence.
2. Prevent - the level most companies should be at
If avoid is impossible, prevent the fall. Examples in order of preference:
- Edge protection - scaffold with handrails and toe boards, guardrails on flat roofs, fixed barriers
- Working platforms - MEWP, scissor lift, podium step, tower scaffold with full edge protection
- Properly secured ladders as a last resort, only for short, light tasks
- Restraint systems - harness + lanyard short enough that the worker cannot reach the edge
Prevent works because there is no fall to manage. Equipment-driven prevent (scaffolds, MEWPs) is the gold standard for any task lasting more than half an hour.
3. Minimise - the last line of defence
Where avoid and prevent are not possible, you minimise the consequences of a fall:
- Fall arrest harness + shock-absorbing lanyard or SRL with verified clearance
- Soft landing systems - air bags, foam pads, safety nets
- Rescue plan rehearsed with on-site equipment and named rescuers
- First aid trained personnel ready for suspension trauma
Minimise alone is not compliance. The HSA will ask why avoid and prevent were rejected before reaching minimise.
Worked example - cleaning gutters on a 2-storey Dublin home
| Level | Option | Decision |
|---|---|---|
| Avoid | Telescopic gutter vacuum from ground | Adopt - covers 90% of length |
| Prevent | Tower scaffold for the gable corners | Adopt for the 10% telescopic cannot reach |
| Minimise | Harness + roof anchor | Not needed - tower scaffold has edge protection |
One job, two avoid+prevent controls, no harness needed. The HSA inspector sees a clean assessment and moves on.
Worked example - replacing a roof tile on a 35-degree slate roof
| Level | Option | Decision |
|---|---|---|
| Avoid | Drone inspection only - tile must physically be replaced | Reject |
| Prevent | Scaffold to eaves with crash deck below working area | Adopt |
| Prevent | Roof ladder hooked over ridge | Adopt |
| Minimise | Harness + roof anchor in restraint configuration | Adopt as belt-and-braces |
This job needs all three: prevent (scaffold + crash deck) + restraint (harness). That is exactly what an HSA inspector wants to see for slate work.
The role of Working at Heights Training
The hierarchy is the spine of the Working at Heights Course online. Every learner finishes the 45-minute course able to walk into a job, look at the task, and pick avoid, prevent or minimise without thinking about it. That habit is what keeps Irish sites compliant year after year.
Three traps to watch for
- Going straight to harness because "we always do harness" - the HSA reads this as no real assessment
- Picking the cheapest option instead of the highest level achievable - the law is "reasonably practicable", not "cheapest"
- Forgetting the rescue plan when minimise is the chosen level - a harnessed worker hanging in suspension trauma is not "minimised" if no-one can get them down
FAQs
Is the hierarchy law or just guidance?
It is law. Section 8 and 19 of the SHWW Act, plus Regulation 96 of SI 299/2007, both reference it directly.
Can I use minimise on its own if prevent is too expensive?
Cost is not a defence in itself. The phrase "reasonably practicable" includes cost balanced against risk - if the consequences are death or permanent injury, very few costs are too high.
Do I need to write the hierarchy down?
Yes. In the risk assessment, in the method statement, and the training records of every worker. The employer compliance pack shows you the format.
Make the hierarchy a habit. Start the Working at Heights Course online in 45 minutes, instant Working at Heights Certificate for every learner.
