- Watch out
- What it costs
- Experienced readers
- Remember
- In BIMpedia
Most of the hazards people face on and in a building are decided at a designer's desk: where plant sits, how high things are, how heavy they are, how people reach them. A contractor can manage risks, but only a designer can remove them. The model is the best place to see them.
The services designer places two air handling units near the roof edge, where there's space. A note on the drawing says "Work at height: maintenance to use fall arrest". For 25 years, every three months, a technician clips on and changes filters next to an open edge.
In the 3D review, the safety advisor and the facilities manager look at the roof together. The units move four metres in, behind a parapet, with a walkway from the roof access hatch. The note becomes unnecessary. The remaining risk (lifting a replacement fan) is recorded against the unit, with the lifting point shown.
Eliminate, reduce, inform
| Step | Question | Roof plant example |
|---|---|---|
| Eliminate | Can the hazard be designed away? | Move the plant away from the edge |
| Reduce | If not, can it be made less likely or less severe? | Permanent guardrail, walkway, lifting point |
| Inform | What's left, and who needs to know? | Record the lift of the replacement fan against the unit |
In the UK, the Construction (Design and Management) Regulations 2015 (CDM) require designers to eliminate, reduce or control foreseeable risks to people who build, use, maintain or demolish what they design, and to provide information about what remains. Many countries have similar duties. Check the rules where you work.
What to look for in the model
- Work at height: plant, valves and lights that need regular access; roof edges; atriums.
- Access and replacement: can the biggest item get in and out, and along which route?
- Heavy lifts: weights near the crane's limits; lifting points.
- Confined spaces: tanks, voids, risers that need entry.
- Escape routes: anything that narrows or blocks them.
Open the BIMpedia Clinic in 3D and look at the roof plant (two air handling units on the roof).
- Which hazards would you look for during maintenance?
- For each, what could the design do first: eliminate or reduce?
- What would you record as a residual risk?
Key takeaways
- The order is always: eliminate, then reduce, then inform. A note on a drawing is the last resort, not the first.
- The model shows hazards drawings hide: work at height, plant access, heavy lifts, confined spaces.
- Record residual risks against the elements they belong to, so they reach the contractor and the operator.
- In the UK, CDM 2015 makes this a legal duty for designers; most countries have a similar rule.
Your notes
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