CDM 2015 has been in force for over a decade. Most construction directors sat through a briefing when the regulations came in, applied what they needed at the time, and got on with running their businesses. The detail, for many, has quietly faded since.
That is not unusual. It is what happens when you are managing projects, people and commercial pressure simultaneously. The problem is that CDM duties do not fade alongside the knowledge. They sit there, live, attached to every notifiable project the business touches — regardless of how clearly the director running that business could articulate them today.
Most directors of growing construction businesses will, if asked directly, acknowledge some uncertainty about exactly where they stand. Not because they are indifferent to it. Because they are running businesses, and the framework has not needed to be tested closely enough, often enough, to stay sharp. The knowledge was there. It has simply not been revisited in a structured way for some time.
This article covers the areas where that drift tends to matter most in practice.
What CDM 2015 actually requires of you as a director
CDM 2015 replaced CDM 2007 and brought some significant shifts that still catch people out. The most important: it removed the old CDM Co-ordinator role and replaced it with the Principal Designer. For many construction businesses, that change did not land cleanly at the time, and some are still operating as if the old structure is in place.
Under CDM 2015, if your project involves more than one contractor, you need a Principal Contractor and a Principal Designer formally appointed. These aren’t optional on notifiable projects — they’re legal duty holder roles with specific responsibilities attached to them.
The five CDM 2015 duty holders
- Client — the organisation or individual having the construction work carried out. Carries more duties than most clients realise, and cannot simply delegate them away.
- Principal Designer — appointed on projects with more than one contractor. Manages health and safety in the pre-construction phase. Must be competent — not just available.
- Principal Contractor — manages H&S during the construction phase. Plans, manages, monitors and coordinates.
- Designer — anyone who prepares or modifies designs for construction work, including temporary works designs.
- Contractor — any individual or business that carries out, manages or controls construction work on site.
Where directors most often get unstuck is in understanding what the Client duty means in practice. Many assume that once a Principal Contractor is appointed, CDM responsibilities have largely been handed over. They haven’t. The Client retains duties throughout: ensuring suitable management arrangements are in place, that sufficient time and resource is allocated, and that the Principal Designer and Principal Contractor are actually doing their jobs.
You can’t fully delegate your way out of it.
The things that actually catch businesses out
Working with construction businesses across London, Surrey and the South East, there are a handful of areas where CDM knowledge tends to have the biggest gaps. None of them are obscure. They are the things that should be straightforward but are not, because nobody has sat down and gone through them properly in a while.
Where CDM knowledge gaps tend to sit
- Not knowing when a project becomes notifiable to the HSE — and what that actually triggers in terms of responsibilities
- Informal Principal Designer appointments, or appointing someone without the competence the role genuinely requires
- Construction Phase Plans that exist on paper but bear no relation to how work is actually managed on site
- Pre-Construction Information not being properly gathered, or not being passed down the supply chain
- Duty holder responsibilities not being properly understood by the people actually holding those roles
- Domestic client situations being mishandled — CDM 2015 still applies when work is carried out on behalf of a domestic client
- Subcontractor appointment without proper competence checking
None of these are exotic. They’re the everyday CDM realities that a growing construction business needs to have properly in hand. When they’re not, the exposure can be significant — not just regulatory, but reputational and commercial.
“The Construction Phase Plan existed. It was on the server. Nobody on site had read it in six weeks, and it hadn’t been updated since the project programme changed. That’s not just a CDM compliance problem. It’s a management problem that CDM compliance is supposed to prevent.”
When did you last actually look at this?
CDM 2015 has been in force since April 2015. If you sat through a briefing when the regulations came in and haven’t revisited them in any structured way since, that’s over a decade of accumulated project experience sitting on top of knowledge that may have quietly drifted.
The regulations themselves haven’t fundamentally changed. But your business has. Your projects are likely bigger and more complex. You’re carrying more duty holder responsibility than you probably were in 2015. You have more supervisors, more subcontractors, more interfaces to manage. The gap between what you knew then and what you need now may be wider than it feels.
And the honest truth is that most refresher conversations — when they happen — take a morning, not a week. The framework isn’t that complicated once you look at it properly. It’s the drift that makes it feel intimidating.
A note on the Building Safety Act 2022. If any of your work involves higher-risk buildings — broadly, residential buildings over 18m or seven storeys — the Building Safety Act has introduced additional obligations that sit alongside and connect with CDM duties. For construction businesses operating in London and the South East, it’s worth understanding where the two frameworks meet. It’s not covered in depth here, but it’s increasingly relevant and worth having clarity on.
What a proper refresher actually looks like
A CDM refresher for directors and senior teams isn’t about sitting in a room being talked at by someone reading from slides. That’s not useful to anyone — and it’s certainly not how experienced people learn or retain anything.
A proper session works through the duty holder framework in the context of how your business actually operates. It covers real scenarios — the situations your teams face on live projects — and works out where your CDM management is solid and where there are genuine gaps. People leave with a clear, practical understanding they can actually use. Not a folder they’ll put in a drawer and forget about.
It should also be honest about what’s genuinely straightforward and what genuinely needs attention. Most businesses aren’t in a catastrophic position. They’re in a position that needs some clarity, some tightening, and a bit of structured thinking applied to it.
CDM15 Refresher for Directors & Senior Teams
A focused one-day live session for construction directors, contracts managers and senior operational managers who want to get their CDM knowledge back to where it needs to be. Practical, honest, and built around how real construction businesses actually operate — not how the textbook says they should.
- The duty holder framework — who holds what
- What Client duties actually require in practice
- Principal Designer — competence and appointment
- Principal Contractor responsibilities on site
- Notifiable projects — triggers and process
- Construction Phase Plans that actually work
- Pre-Construction Information — gathering and passing down
- Competence checking through your supply chain
- Where CDM and the Building Safety Act connect
- Common gaps found in practice — and how to close them
Available for in-house delivery across London, Surrey and the South East. Small group format — up to 12 participants. Tailored to your business and the types of projects you carry out.
Ask about availability →If any of this resonates — the uncertainty about where the business actually stands, or a sense that CDM knowledge across the team could do with being properly tested — it is worth a conversation. A straightforward discussion, no obligation, that usually leaves people with a clearer picture than they had going in.