28th July, 2020

Who Does CDM 2015 Apply To?

The Construction (Design and Management) Regulations 2015 (CDM 2015) apply to all construction work, but who is responsible for complying with these regulations? Every construction project, no matter how big or small, short or long, needs to comply with CDM, and CDM applies to everyone involved.

Who Does CDM 2015 Apply To? header image

If you work in construction, then you need to know about the Construction (Design and Management) Regulations 2015 (CDM), because they apply to you. You see, CDM doesn't just apply to construction work, but to the people who carry out that work. Whether it's a builder, a tradesman (or woman), the architect, engineer, interior designer, or even the client. Everyone must comply with CDM.

Who does CDM 2015 apply to? The answer, more often than not, is everyone.

And you can't just leave the handling of CDM down to one person on the project. Just like the project itself, CDM is a group effort. Construction work often involves many different people and businesses coming together to complete a project. And they each need to take care of their safety, but also ensure that the people involved can work safely on the site too.

That’s right, it is not just down to the contractor, or the principal contractor, or the principal designer to comply with CDM. Nearly everyone involved in the project will have some duties under CDM 2015.

There are 5 main duty holders:

  1. Client
  2. Principal Designer
  3. Principal Contractor
  4. Designers
  5. Contractors

The Client

Initially, the first person CDM 2015 will apply to is the client. That is before anyone else is appointed. The client may not be directly involved in the construction work, and might not even know much about the health and safety hazards, laws, or requirements surrounding it. But despite this, clients have duties under CDM for good reason. They can have a big impact on health and safety.

You might be wondering how a client can improve health and safety on a site they might not visit, on the type of work they are not involved in, in an area they may not have much interest in. After all, many clients choose to take a hands-off approach and let the builder get on with it. But the decisions a client makes about the project, the people they choose to do the work, the budget and timeframe they allow, the information they share with the team, can all help (or hinder) health and safety.

Unless the client is a domestic client* (having work done in their own home not connected to any business), they are responsible for appointing the principal contractor (or sole contractor) and principal designer in writing. They must allocate sufficient time and resources to the project, ensure welfare facilities are provided, and that the work can be carried out without risk to health and safety.

*on domestic projects the appointment of the Principal Designer and Principal Contractor is usually automatic.

The client is also responsible for notifying the HSE where the project is notifiable and providing the pre-construction information. While the client isn't expected to manage the work themselves, they are expected to take steps to make sure that those that are (like the principal designer and principal contractor) comply with CDM.

The Principal Designer

The principal designer is often the first appointment a client makes, this could be the main architect for the project or another designer, or sometimes (on a design and build contractor for example) it may be the builder.

principal designer

There is only one principal designer on a project at any one time, while there may be many designers. The principal designer has the overall responsibility of complying with CDM 2015 during the pre-construction phase and ensuring that all designers carry out their own CDM duties.

The principal designer has lots of duties under CDM. Before work starts, they will often need to assist the client, liaise with the principal contractor, and gather information from the client the designers to pass on to the principal contractor. During the work, apart from design changes, information mostly flows the other way, from the contractors back to the principal designer for inclusion in the health and safety file.

The Principal Contractor

The principal contractor is in overall control of the construction phase and is responsible for CDM duties on-site, including the construction phase plan, inductions, welfare, and ensuring that contractors comply with CDM 2015.

principal contractor

As with the principal designer, there can be only one principal contractor appointed at any one time on the project. The principal contractor is in charge of and responsible for the safety of all the other contractors on site. While contractors have their own health and safety responsibilities and duties under CDM, the principal contractor has overall responsibility for running the site.

Most of the principal contractor duties happen once work starts on site, but of course, they need time to prepare as well. In addition to managing health and safety on the site, the principal contractor will share health and safety information with contractors and the principal designer, and provide information for the client on project completion.


Designers need to apply CDM to every design they prepare that relates to construction work. That could be the design of the whole house, or just an individual structure or service. And designer duties don't just apply to designers, but anyone who prepares a design for construction. The client might specify an element of the design. The structural engineer is likely to be involved in the design. Manufacturers may supply drawings and specifications. Electricians and plumbers might design services. The builder may have an input on the design too.

Essentially, designers must consider health and safety, including the principals of prevention and the pre-construction information when preparing a design. Eliminating or reducing any risk as far as is reasonably practicable.

Designers must also provide information about any risks associated with their design to the principal designer so that this information can be included if necessary in the pre-construction information, health and safety file, and communicated with the rest of the project team.


CDM also applies to every contractor involved in the project, no matter how big, small, long or short their involvement. There will often be several different contractors involved in a project, and each contractors work could create hazards and risks for the other contractors on site. CDM requires contractors to work together, not just to manage their own work, but to consider everyone involved in the project.


Contractors need to plan, manage and monitor their own work, to ensure that is carried out safely. And they must also comply with the [construction phase plan](/documents/cdm/construction-phase-plan-template and any directions given to them from the principal contractor. Like designers, contractors must also take into account the principals of prevention when it comes to planning and carrying out their work.

Anyone a contractor engages to carry out construction work must have the necessary skills, knowledge, training and experience to do the work safely, and the contractor has a duty to provide them with appropriate supervision, instruction and information.

So CDM applies to clients, the principal designer, the principal contractor, designers and contractors. Each has different duties under CDM, and while we have summarised some of those duties in this post, you can get a full breakdown of each role in our free CDM guides.

And when we say CDM 2015 applies to everyone, it really is true. Workers also have duties under CDM 2015, to take care of their own health and safety and cooperate with other duty holders.

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This article was written by Emma at HASpod. Emma has over 10 years experience in health and safety and BSc (Hons) Construction Management. She is NEBOSH qualified and Tech IOSH.

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