CDM 2015 removed the role of CDM coordinator and replaced it with two distinct duty holders. If you are still asking whether you need a CDM coordinator, it is worth understanding what the regulations actually require now.
The term CDM coordinator causes more confusion than most in construction health and safety. It was a formal role under the previous version of the Construction (Design and Management) Regulations, but CDM 2015 abolished it entirely and replaced it with a different structure. Many clients, contractors and developers are still using the old terminology, and that confusion can lead to gaps in how projects are set up and managed.
This article explains what CDM 2015 actually requires, which roles exist under the current regulations, and when bringing in external CDM support makes sense.
What CDM 2015 Replaced
Under the 2007 version of the CDM Regulations, a CDM coordinator was required on notifiable projects. They were responsible for coordinating health and safety during the design and pre-construction phase, advising the client on their duties and managing the flow of information between duty holders.
When CDM 2015 came into force, those responsibilities were redistributed. The CDM coordinator role disappeared. In its place, the regulations introduced the Principal Designer as the key pre-construction duty holder, alongside the continued role of Principal Contractor for the construction phase. The client’s own duties were also strengthened considerably under the new framework.
The Duty Holders Under CDM 2015
CDM 2015 applies to all construction projects, regardless of size, value or duration. For most projects involving more than one contractor, two appointments become legally required: a Principal Designer and a Principal Contractor. Both must be appointed in writing.
The Principal Designer is responsible for planning, managing and monitoring health and safety during the pre-construction phase. This includes coordinating design risk, ensuring that hazards are identified and addressed early, and producing or overseeing the pre-construction information pack. It is a proactive, ongoing role that sits within the design process rather than sitting alongside it.
The Principal Contractor takes over as the lead duty holder once construction starts on site. They are responsible for managing health and safety throughout the build phase, producing the Construction Phase Plan, coordinating subcontractors, and ensuring that site arrangements are compliant and well managed.
The client sits above both. Under CDM 2015, clients have their own legal duties and cannot simply delegate their responsibilities away. They must ensure that suitable arrangements are in place before work starts, that duty holders are competent and properly appointed, and that the project is set up to allow health and safety to be managed effectively.
When Does CDM Apply?
CDM 2015 applies to all construction work. There is no minimum threshold for a project to fall within scope. Whether you are carrying out a small fit-out, a refurbishment of a commercial premises or a large-scale infrastructure project, the regulations apply.
The duty to appoint a Principal Designer and Principal Contractor arises when more than one contractor is involved. If the project also meets the notification threshold (more than 30 working days with over 20 workers on site simultaneously, or more than 500 person-days of construction work), it must be notified to the HSE. Notification does not change the legal duties, but it does place the project on HSE’s radar.
So What Does a CDM Consultant Actually Do?
Since the CDM coordinator role no longer exists, what many businesses are actually asking when they use that term is: who helps us navigate CDM compliance?
The answer is typically an external CDM consultant, who can provide support in several ways depending on what the project needs. On some projects, they fulfil the Principal Designer role directly. On others, they provide advisory support to an existing Principal Designer, helping them discharge their duties correctly. Some clients engage a CDM consultant purely to support their own client-side obligations, ensuring they understand what they are required to do and that they can demonstrate they have done it.
In each case, the value of external CDM support comes from experience. The regulations place substantial responsibilities on duty holders, and the consequences of getting it wrong range from enforcement action and prosecution through to personal liability for directors and senior managers.
Common Situations Where CDM Support Makes Sense
Projects with multiple subcontractors, complex interfaces between designers and contractors, or clients who lack in-house construction expertise are the most common cases where external CDM support is sought. But it is not limited to large or complex schemes.
Smaller contractors who take on the Principal Contractor role for the first time often benefit from guidance on what their Construction Phase Plan needs to cover, how to structure their inductions and briefings, and what records they need to maintain. Developers and property owners acting as CDM clients frequently need support understanding what their duties actually mean in practice and how to fulfil them without becoming inadvertently liable for gaps in their project team’s arrangements.
The key question is not whether your project is large enough to need CDM support, but whether the people responsible for the various duties are genuinely competent to fulfil them. CDM 2015 is explicit on this point: competence is a requirement, not an aspiration.
Getting CDM Right from the Start
The most effective CDM support is engaged early, ideally at the design stage rather than once construction is already underway. By that point, many of the decisions that most affect health and safety during the build have already been made, and changing them becomes costly and disruptive.
Early engagement allows hazards to be identified and eliminated or reduced through design before they become site problems. It also gives the Principal Designer time to build a coherent pre-construction information pack and establish the working relationships with designers and contractors that CDM compliance depends on.
Mast Safety provides CDM consultancy support across the UK, acting as Principal Designer, providing Principal Designer advisory services, and supporting clients in understanding and discharging their own duties. If you are planning a project and want to understand what CDM support you need, our team is happy to discuss your specific situation.
