What CDM 2015 is, the dutyholders and their roles, the key documents, when a project is notifiable to the HSE, what changed from CDM 2007, and how to get trained.
The Construction (Design and Management) Regulations 2015, known across the industry as CDM 2015, are the backbone of construction health and safety law in Great Britain. They decide who is responsible for what on a project and what each person has to do. This guide explains what CDM 2015 is, the dutyholders and their roles, the key documents, when a project must be notified to the HSE, and how the rules changed from the old regulations.
CDM 2015 is the main set of regulations for managing health, safety and welfare on construction projects. The regulations apply to all construction work, from a small refurbishment to a major build, and they place legal duties on nearly everyone involved. The aim is simple: to make sure health and safety is built into a project from the very first design decisions, not bolted on once work starts. CDM 2015 is enforced by the Health and Safety Executive (HSE).
One of the most important things about CDM 2015 is that it applies to every construction project, whatever its size. There is no lower limit. What changes with the size and risk of a project is the amount of management and paperwork needed, not whether the regulations apply. A client having a single wall rebuilt has CDM duties, just as the client of a major scheme does.
CDM 2015 defines a set of dutyholders so that responsibility for health and safety is clear at every stage. Each has a specific role, from the client who commissions the work to the workers who carry it out.
| Dutyholder | Who they are | Main duty |
|---|---|---|
| Client | Anyone who has construction work carried out for them | Make sure the project is suitably managed so that health and safety is protected throughout. |
| Principal Designer | A designer appointed by the client where there is more than one contractor | Plan, manage and coordinate health and safety during the pre-construction (design) phase. |
| Principal Contractor | A contractor appointed by the client where there is more than one contractor | Plan, manage and coordinate health and safety during the construction phase. |
| Designer | Anyone who prepares or modifies a design, such as an architect or engineer | Eliminate, reduce or control foreseeable risks through the design. |
| Contractor | Anyone who carries out or manages construction work | Plan, manage and monitor their own work and the workers under their control. |
| Worker | Anyone who works on a construction site | Work safely, follow their training and instructions, and report anything dangerous. |
The two appointed roles, the principal designer and the principal contractor, are only required when a project involves more than one contractor. On those projects the client must appoint both in writing.
The trigger is straightforward: if a project involves, or is likely to involve, more than one contractor, the client must appoint a principal designer to coordinate health and safety in the design phase and a principal contractor to coordinate it during construction. If there is only ever one contractor, that contractor takes on the relevant duties and no separate principal contractor is needed. The principal designer role was introduced by CDM 2015 and replaced the old CDM coordinator, moving the responsibility to someone in a position to influence the design.
CDM 2015 is built around three documents that pass health and safety information along the life of a project. Under the previous regulations these were only needed on notifiable projects; under CDM 2015 they are required according to the project, not just the largest jobs.
| Document | Who prepares it | Purpose |
|---|---|---|
| Pre-construction information | Client | The information designers and contractors need to plan and carry out the work safely. |
| Construction phase plan | Principal Contractor, or the sole contractor on a single-contractor job | How health and safety will be managed during construction. It must be in place before work starts. |
| Health and safety file | Principal Designer | A record of information for whoever maintains, cleans or demolishes the building in future. Required where there is more than one contractor. |
Together these documents make sure that what one party knows about the risks is passed to the next, all the way through to the people who will maintain or eventually demolish the finished building.
Some projects must be notified to the HSE before work starts, using a form called the F10. A project is notifiable if the construction work will last longer than 30 working days and have more than 20 workers on site at any one time, or if it will involve more than 500 person-days of work. A person-day is one worker working for one day, so ten workers for fifty days is 500 person-days.
It is important to understand that notifying the HSE does not change anyone's duties. The CDM duties apply whether or not a project is notifiable; notification simply tells the regulator that a larger project is taking place.
CDM 2015 replaced the Construction (Design and Management) Regulations 2007. The main changes were:
A domestic client is someone who has construction work done on their own home, not in connection with a business. CDM 2015 brought these projects into scope, but in practice a domestic client's duties normally pass to others. Where the domestic client does not make the appointments, the contractor, or the principal contractor where there is more than one contractor, usually takes on the client duties, and the designer in control of the pre-construction phase acts as the principal designer.
The quickest way to understand the regulations is a focused CDM Awareness course, which covers the dutyholder roles and the key documents in a day. CDM duties also run through the wider CITB Site Safety Plus courses: they are a core part of the SMSTS course for site managers and the SSSTS course for supervisors, and they are covered from a leadership angle in the Director's Role for Health and Safety course. Which one suits you depends on your role: awareness for a general grounding, SSSTS or SMSTS for managing a site, and the director course for board-level responsibility.
CDM 2015 is the common name for the Construction (Design and Management) Regulations 2015, the main set of health and safety regulations for construction projects in Great Britain. They set out who is responsible for managing health and safety on a project and what they have to do, from the earliest design work through to handover.
CDM 2015 applies to all construction work, of any size, and to nearly everyone involved: the client, designers, the principal designer, the principal contractor, contractors and workers. The duties scale with the size and risk of the project, but the regulations themselves apply to every job.
The dutyholders are the client, the principal designer, the principal contractor, designers, contractors and workers. Each has a defined role. The table above sets out who they are and what their main duty is.
The principal designer is a designer appointed by the client to plan, manage and coordinate health and safety during the pre-construction phase. The role was introduced by CDM 2015 and replaced the old CDM coordinator, putting responsibility with someone able to influence the design.
The principal contractor is a contractor appointed by the client to plan, manage and coordinate health and safety during the construction phase. They control the site while the work is carried out.
You must appoint both in writing whenever a project involves, or is likely to involve, more than one contractor. If there is only ever one contractor, that contractor takes on the relevant duties and a separate principal contractor is not needed.
A construction phase plan sets out how health and safety will be managed during the construction work. The principal contractor, or the sole contractor on a single-contractor job, prepares it, and it must be in place before construction begins. Under CDM 2015 it is required on every project.
The health and safety file is a record of information that anyone carrying out future work on the building, such as maintenance, cleaning or demolition, will need to do that work safely. The principal designer prepares it on projects with more than one contractor.
A project is notifiable using form F10 if the construction work will last longer than 30 working days and have more than 20 workers on site at any one time, or if it will involve more than 500 person-days of work. Notifying the HSE does not change the duties, which apply whether or not a project is notifiable.
The main changes were replacing the CDM coordinator with the principal designer, requiring the key documents (pre-construction information, construction phase plan and health and safety file) on all projects rather than only notifiable ones, and bringing domestic client projects within scope.
Yes. CDM 2015 brought domestic clients into scope, but their duties normally pass to others. Where a domestic client does not make appointments, the contractor (or principal contractor) usually takes on the client duties, and the designer in control of the pre-construction phase acts as principal designer.
A focused CDM Awareness course covers the regulations and the dutyholder roles in a day. CDM duties are also a core part of the SMSTS course for site managers and the SSSTS course for supervisors, and they are covered at board level in the Director's Role for Health and Safety course.