24th February, 2021

How To Appoint A Principal Designer Under CDM 2015

CDM 2015 introduced a new role of principal designer for most construction projects. This CDM duty holder needs to be appointed in writing by the client on any project with more than one contractor. In this post, we look at how to appoint a principal designer.

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The Construction (Design and Management) Regulations 2015 (known as CDM 2015) introduced a new role of principal designer. And although these regulations have now been in force for over five years, many clients carry out projects infrequently, and may still be unfamiliar with the current requirements.

So, if you're not sure how to appoint a principal designer, or even if you need to, this post is here to help!

As the client of a construction project, you are the person paying for the work and the key decision-maker in terms of, who does what and when. You select your contractors, designers and set deadlines and budgets. You might not realise it, but all of these things can have a huge impact on health and safety. Pick a shoddy builder, or push for an unachievable deadline, and corners might be cut. And that's when things tend to go wrong. For these reasons, clients have legal duties under CDM, just like other members of the project team.

There used to be a CDM coordinator who would act as the clients CDM advisor. Helping the client with their CDM duties, and taking control of most of the CDM responsibilities and checks throughout the project. However, this role was removed the latest version of the CDM regulations in 2015. Now, the majority of CDM duties are split between the client, the principal designer and the principal contractor.

The principal designer is the designer in overall control of the pre-construction phase of your project. That's everything up to when construction work starts. When you're planning what needs to be done, getting bids, selecting your team, agreeing on budgets and timeframes etc. The principal designer will assist the client, make sure all of the design work is coordinated, prepare information and that other team members comply with CDM.

If you want more information on the principal designer, you can read the principal designer role, duties and responsibilities for a deeper understanding.

cdm management meeting

Because the principal designer is essentially responsible for health and safety at the pre-construction stage, they need to be appointed early. This should be the first appointment a client makes, especially if they need help with CDM. In fact, it is the clients' legal duty to make this appointment, and if you don't, you become the principal designer! And that means becoming responsible for all of the principal designer duties. But how do you appoint a principal designer and comply with CDM 2015?

When do you need a principal designer?

Previously (under CDM 2007), additional duty holders were only required on notifiable projects. However, under the new regulations, notification is no longer the trigger for additional appointments. Now, both the appointments of the principal designer and the principal contractor must be made on any project with more than one contractor.

Even a small none-notifiable refurbishment project with a plumber and a decorator should, therefore, have a principal designer appointed under the new regulations.

  1. Where there is more than one contractor, or if it is reasonably foreseeable that more than one contractor will be working on a project at any time, the client must appoint in writing—
    1. a designer with control over the pre-construction phase as principal designer; and
    2. a contractor as principal contractor.

Find out if you need a principal designer and get more details in when does a principal designer need to be appointed?

Who should you appoint as the principal designer?

Identifying the correct person to carry out this role is key to complying with CDM. Rather than a straight swap for the former role of CDM coordinator, the principal designer should be a designer in control of the pre-construction phase of the project.

cdm designer

The principal designer must have the right skills and experience to be able to perform the role. The principal designer will usually be an organisation or, on smaller projects, an individual with:

All designers have duties under CDM 2015. However, the principal designer has duties in addition to their duties as a designer, including taking control of health and safety at the pre-construction phase of the project and assisting the client with CDM requirements. When choosing your principal designer, it is important to remember that the principal designer must be a designer on the project and be in a position to have control over the design and planning stage.

Get more information on the principal designer in the principal designer role, duties and responsibilities to help you choose a suitable principal designer for your project.

How should you appoint a principal designer?

Once you know you need a principal designer and have chosen your principal designer, you can appoint them on your project. The CDM 2015 regulations specify that the appointment must be made in writing.

  1. Where there is more than one contractor, or if it is reasonably foreseeable that more than one contractor will be working on a project at any time, the client must appoint in writing
    1. a designer with control over the pre-construction phase as principal designer; and
    2. a contractor as principal contractor.
cdm client

This written appointment is especially important if you have more that one designer working on your project. Your written appointment gives clear instruction for who is taking on the additional requirements of the principal designer role. It also gives you a record of the appointment and a record of the designer's acceptance of the appointment and additional duties.

Need to appoint a principal designer? Use the principal designer appointment template to create a written record.


As a client, your duty under CDM regarding the principal designer does not end at appointment. You must also take reasonable steps to ensure the principal designer complies with the principal designer duties.

Find out more about your client duties in our free CDM duty holder guide for clients and use the free CDM compliance checklist to score your project.

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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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