Putting People Back at the Centre of CDM: Why CDM is about behaviours, not just compliance
Written by Craig Melhuish, Head of Programme & Project Management
At its heart, Construction (Design and Management) Regulations 2015 (CDM) is about planning, designing and delivering work safely so people do not get hurt during construction or long after.
In simple terms, CDM outlines the legal responsibilities and accountabilities of duty holders regarding health and safety management on construction projects in the UK.
Everyone involved in construction must understand CDM. It sits alongside the Health and Safety at Work Act 1974 and the Management of Health and Safety at Work Regulations 1999, forming part of the wider legal framework designed to protect people.
It is there to protect people, not hinder delivery. When done properly, it builds confidence and keeps people safe.
Three years ago, when I stepped into my current role, as a lead for Site Construction Safety and assurance, I quickly realised there were gaps in how we, as an industry, understood CDM. Not through lack of effort, but because of a simple truth: you do not know what you do not know. Unless someone helps you understand it, the cycle continues.
One of my earliest conversations was about surveys:
- “Is this intrusive or non-intrusive?”
- “If you are breaking ground, it is construction.”
- “This is enabling works, that isn’t construction, is it?”
- And one that stuck with me: “It is only 35m of cable tray.”
That “it is only…” mindset is where things start to slip. The moment we downplay the task; we stop applying the same level of thinking to risk.
What shaped my thinking
Early in my career, I managed the delivery of station platform extensions. That is when CDM first really clicked for me, not as a process, but as a way of thinking.
The idea that what you design must be built, used, maintained and eventually removed safely was the moment it landed with me.
One example that has stayed with me is a media centre at an international stadium. It is an iconic structure, uncompromising in its design, but it created real challenges for maintenance. In particular, window cleaning, is difficult because of its curved, boat-like form.
It looks great, but with more thought at the design stage, the maintenance challenges could have been avoided. I still come back to that example. Good design is not just about how something looks; it is about how safely it can be built and maintained over its whole life.
Why organisations struggle with CDM
A lot of it comes down to visibility.
It is not that CDM does not apply. It is that people do not always see how their role influences it.
Take procurement. Their responsibilities do not always sit neatly under a named duty holder in the regulations, so the link to their duty to allow sufficient time for planning and delivery is not always obvious. But if procurement slips and delivery dates do not move, you have taken time out of planning. That’s where risk starts to creep in, because less time means less opportunity to plan, coordinate and manage it properly. Add constantly changing teams and multiple suppliers, and you introduce a different kind of complexity. You end up repeatedly re-explaining CDM expectations.
When interpretation becomes “fact”
Health and Safety executive guidance and industry standards are clear and available to everyone. But not everyone reads them, so people rely on others. Over time, interpretation becomes “truth” for the next person.
I have always been someone who asks when I do not know. In this role, I often found myself doing something slightly different: pointing people back to the source. In doing that, I sharpened my own understanding too.
Create an environment where people are comfortable asking questions. When people understand CDM, they do not just do the job; they change how the job is done.
Craig Melhuish
Head of Programme & Project Management
What I was seeing on projects
Before we made changes, I was seeing:
- Pre-Construction Information Packs (PCIPs) pushing responsibility onto Contractors when it sits with the client
- Construction Phase Plans (CPP) that were 70+ pages long, heavy on generic content but light on actual project-specific risk
- Hazards, risks and controls copied across from other jobs that were not applicable
- Templates reused without using the guidance behind them
The information was there, but it was buried.
And when reviewers step in and fix things, the message becomes:
“It does not matter if it is wrong. Someone else will sort it.”
That is not competence. That is dependency.
What we did differently
We simplified the approach the teams were taking, emphasising that less is more. We held firm consequences. If it was not right, the work did not go ahead. Then we focused on behaviours:
- Build CPPs together, not in isolation
- Use the guidance and standards as your starting point, not the last job
- Speak to the right people early in the development process
- Spend time upfront to avoid fixing things later
This was not about catching people out. It was about helping them get it right.
What improved
The shift has been noticeable. People are more curious, they question things, and they challenge each other.
The fear of getting it wrong has been replaced with the confidence to ask questions.
And that has made a bigger difference than any template ever has.
One piece of advice
CDM is not complicated. We make it complicated. Go back to the source, understand your duties, and speak up early.
The regulations are clear. The information is out there. It is not hard to find. Where people go wrong is by overcomplicating it or relying on others to interpret it for them.
If you are unsure, ask, whether that’s your internal team, experienced colleagues or external support where needed. That is how you learn, and it is how you avoid getting it wrong.
And if something does not feel right, it probably is not.
Final thoughts
CDM is not about paperwork. It is about keeping people safe from harm during construction and long after the work is complete.
It is also the law. The consequences of getting it wrong can be significant, not just for organisations, but for the people affected by poor decisions.
Keep it simple. Understand your role and others in discharging duties under CDM.
Create an environment where people are comfortable asking questions. When people understand CDM, they do not just do the job; they change how the job is done.
How Mercury3 Consult can help
At Mercury3 Consult, we help organisations put the right structure around CDM, so people understand what is expected of them and feel confident carrying it out.
That structure is not about adding paperwork. It is about embedding CDM into how projects are planned and delivered, from early concept through procurement to delivery and handover.
We support organisations in achieving compliance with CDM in a way that is practical and proportionate, helping duty holders understand their responsibilities and how those responsibilities fit together.
A big part of our role is creating environments where people feel comfortable asking questions, challenging assumptions and learning from each other. That is what builds competence, encourages curiosity and strengthens psychological safety across teams.
We simplify expectations, clarify duty holder responsibilities and provide practical frameworks that teams can build around, so compliance becomes the outcome of good planning, not a paperwork exercise at the end.
If you would like to discuss how we can support your organisation in embedding CDM, strengthening compliance and improving assurance across the project lifecycle, contact us today.
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