Compliance Guide

CDM 2015 Duty Holders Explained: Who Does What

A practical guide for UK site managers, contractors and small builders.

CDM 2015 works by handing everyone on a construction project a defined job in managing health and safety. These roles are called duty holders, and each one carries its own set of legal duties. Get the roles clear and a project runs with responsibility in the right hands. Get them muddled and jobs fall through the cracks, which is exactly what CDM was written to prevent. Here is who each duty holder is, what they have to do, and how the roles fit together in plain English.

What a duty holder means under CDM 2015

A duty holder is simply a person or organisation that CDM 2015 gives specific health and safety responsibilities to. The regulations name six of them, running from the person who commissions the work down to the people carrying it out. The point is that health and safety is not one person's problem to solve at the end. It is shared across the life of a project, with the right duty best placed to deal with each risk. The list below is the standard chain most jobs are built on.

The client

The client is the person or organisation the construction work is carried out for. They sit at the top of the chain and set the tone for the whole project. Their duties include making sure suitable arrangements are in place for managing the work, appointing the other duty holders where required, providing pre-construction information, and allowing enough time and resource for the job to be done safely. On projects with more than one contractor the client must appoint a principal designer and a principal contractor in writing. If they do not, the client takes on those duties themselves.

The principal designer

The principal designer is appointed by the client to manage health and safety during the pre-construction phase, the design and planning stage. They plan, manage and monitor that phase, coordinate the design so foreseeable risks are eliminated, reduced or controlled, help pull together pre-construction information, and prepare the health and safety file. The role only exists on projects with more than one contractor. It is about designing risk out before anyone reaches for a tool.

The principal contractor

The principal contractor takes over for the construction phase, once work starts on site. They plan, manage and monitor that phase, draw up and update the construction phase plan, coordinate the contractors working on site, and make sure the site is secure with the right welfare facilities and site induction in place. Like the principal designer, this role is only required where more than one contractor is involved. One designs the risks out, the other manages what is left on site.

Designers

A designer is anyone who prepares or modifies a design, or arranges for or instructs someone else to. That covers architects and engineers, but also anyone whose decisions shape how something is built. Their duty is to eliminate, reduce or control foreseeable risks through their design choices, applying the general principles of prevention, and to provide information about any remaining risks so others can plan around them. Designers work under the coordination of the principal designer where one is appointed.

Contractors

A contractor is anyone who manages or carries out construction work. They plan, manage and monitor their own work and anyone they employ, and they comply with directions from the principal contractor. On a single contractor project the contractor also picks up duties that would otherwise fall to the principal contractor, including preparing a construction phase plan. Contractors are the ones turning the design into a finished structure, and their duties keep that work safe day to day.

Workers

Workers are the people who carry out the construction work itself, the trades and operatives on site. Their duties are to look after their own health and safety and that of others affected by their work, to cooperate with their employer and other duty holders, to report anything they see that is likely to endanger someone, and to follow the training and instruction they are given. They are the last link in the chain and often the first to spot a hazard developing.

How the roles fit together

The six duty holders form a chain that runs across the life of a project. The client commissions the work and sets it up properly. The principal designer manages risk while the job is still on paper. The principal contractor manages it once work is under way. Designers and contractors carry out their parts under that coordination, and workers do the work safely on the ground. Each role hands information to the next, so pre-construction information flows into the construction phase plan, and the health and safety file is carried forward for whoever works on the structure next.

The rule in one line: CDM 2015 names six duty holders, client, principal designer, principal contractor, designers, contractors and workers, and gives each a defined health and safety job so that risk is managed by whoever is best placed to deal with it, from design through to the tools on site.

Frequently asked questions

Who are the duty holders under CDM 2015?

There are six: the client, the principal designer, the principal contractor, designers, contractors and workers. Each has its own set of health and safety duties across the design and construction of a project.

Which duty holders are only required on some projects?

The principal designer and principal contractor are only required where there is, or is likely to be, more than one contractor. The client, designers, contractors and workers have duties on every project, whatever its size.

What happens if the client does not appoint a principal designer or principal contractor?

On a project that requires them, if the client does not make the appointments in writing, the client takes on those duties themselves. It does not remove the duties, it just leaves them with the client.

The shortcut

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This article is general guidance for UK construction and is not legal advice. For requirements specific to your work, check current HSE guidance and your own duty holder obligations under CDM 2015.