CDM 2015 duty holders explained

Client

The client is whoever has construction work carried out for them as part of a business. The client is the top of the chain and their duties set the tone for the project. They must make suitable arrangements for managing the project, allocate sufficient time and resources, provide pre construction information, ensure a construction phase plan exists before work starts, ensure welfare is provided, and ensure the health and safety file is prepared and kept.

Where there is more than one contractor, the client must appoint the principal designer and principal contractor in writing. If they do not, the client takes on those duties themselves by default under regulation 5, which is a trap for clients who assume silence means someone else is responsible.

The principal contractor's first deliverable is the construction phase plan, and it must exist before work starts.

Domestic client

A domestic client has work done on their own home, not in connection with a business. Their duties pass automatically to the contractor on a single contractor project, or to the principal contractor where there is more than one, unless a written agreement places them with the principal designer.

Contractors working for homeowners should build this into their quotations and explain it, because the homeowner will not know and the contractor is carrying the risk either way.

Site paperwork a principal contractor will always ask for includes scaffold inspection records.

Principal designer and designer

The principal designer plans, manages and monitors the pre construction phase and coordinates health and safety in it. They must ensure designers comply with their duties, help the client gather and issue pre construction information, liaise with the principal contractor and prepare the health and safety file.

Any designer, including architects, engineers, and contractors who carry out design work, must eliminate foreseeable risks through design so far as reasonably practicable, then reduce or control what remains, and provide information about significant residual risks. Specifying a detail that can only be built by someone leaning out over an unprotected edge is a design failure, not a site failure.

Note that the Building Safety Act regime adds separate dutyholder and competence requirements for higher risk buildings, which sit alongside CDM rather than replacing it.

Principal contractor and contractor

The principal contractor plans, manages and monitors the construction phase. That means preparing and maintaining the construction phase plan, coordinating the contractors on site, securing the site, providing site inductions, ensuring welfare, and consulting and engaging with workers.

Every contractor, including sole traders, must plan, manage and monitor their own work, not start until reasonable steps are taken to prevent unauthorised access to the site, comply with directions from the principal contractor, and provide their workers with information, instruction, training and supervision.

Workers

Workers must be consulted on matters affecting their health, safety and welfare, must take care of themselves and others, must report anything they see that is likely to endanger anyone, and must cooperate with their employer.

The consultation duty is frequently forgotten. Regulation 14 requires the principal contractor to engage with workers, not simply to inform them. Evidence of that engagement, through safety committees, worker representatives or documented site forums, is what distinguishes a well run site under inspection.

Appointments, competence and the paperwork trail

Regulation 8 requires that anyone appointed has the skills, knowledge, experience and, where an organisation, the organisational capability to carry out the role. There is no CDM licence, so the client must actually check. Reasonable checks are qualifications, membership of a professional body or a recognised assessment scheme, references from comparable projects and a look at the proposed team.

Keep the trail: written appointments, the pre construction information issued and dated, the construction phase plan before work starts, the health and safety file at the end. Those four documents, correctly dated, answer most CDM questions an enforcing authority will ask.

Where duty holder confusion actually causes harm

Most CDM failures are not exotic. They are a client who never appointed anyone in writing, so nobody planned the job; a principal designer appointed after design was finished, so buildability risk was never designed out; or a principal contractor with no realistic time or money in the programme to work safely. Each of those is a paperwork failure that turns into a site failure.

Appointments must be in writing and must be made before the construction phase begins. If a client does not appoint, the client carries those duties themselves, which is rarely what a domestic or small commercial client intends. On a domestic project the duties normally pass to the contractor, or to the principal contractor where there is more than one, unless there is a written agreement with the principal designer.

Competence is now framed as skills, knowledge, experience and, for organisations, organisational capability. Ask for evidence proportionate to the risk: relevant project examples, training records and how the firm plans the work, not just a membership logo.

Common questions

Does CDM apply to small jobs?

Yes. CDM 2015 applies to all construction work regardless of size or duration. Notification to the HSE is separate and only applies above the thirty day or five hundred person day thresholds.

Can one company be both principal designer and principal contractor?

Yes, provided it has the skills, knowledge, experience and organisational capability for both roles, and the client appoints it in writing to each.

What is pre construction information?

Information already in the client's possession or reasonably obtainable about the site and the project, including surveys, asbestos registers, services drawings and existing structural information.

Related guides

• construction phase plan
• scaffold inspection records