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The impact of the CDM 2015 and the principal designer role after the end of the transition period

02 November 2015 #Construction


The six month transition period for the Construction (Design and Management) Regulations 2015 (“CDM 2015”) ended on 6 October 2015 and this signifies the dawn of a new focus on design as the key to health and safety operation on construction projects.

The change that has had the most impact is the creation of the new role of a principal designer. This fundamentally replaces the now abolished CDM co-ordinator role. The principal designer has an important role in influencing how risks to health and safety are managed throughout a project, and the role combines elements of health and safety advisor and a technical designer. This moves away from the bureaucratic, ‘box ticking’ approach that was suggested by some to be the hallmark of the planning supervisor and CDM co-ordinator roles and towards a system where health and safety issues are considered at the earliest opportunity and are embedded in the design process.

Therefore now the CDM 2015 is fully in force, it is important to take a more pragmatic viewpoint to assess the principal designer role in more detail. In particular, I will address:

1) who can be appointed as principal designer;
2) what must a principal designer do;
3) whether a consultant can refuse to be appointed as a principal designer; and
4) whether you can sub-contract the role of a principal designer.

1. Who can be appointed as principal designer?

The answer to this question lies in regulation 5 of the CDM 2015. It requires the client to appoint a principal designer (and a principal contractor) if there is (or is likely to be) more than one contractor on the project. The client must appoint in writing:

…a designer with control over the pre-construction phase as principal designer.”

On the face of it, this seems clear, as the principal designer must:

  • Be a designer; and
  • Have control over the pre-construction phase.

These criteria initially appear to apply to quite a limited range of professionals; however, in practice it covers a larger range of parties due to the wide drafting of the definition of ‘design’ and ‘designer’. Therefore, an architect, structural engineer or a quantity surveyor who has sat within the CDM client’s team from the pre-construction phase is likely to meet the criteria of the principal designer role. Equally, a project manager who co-ordinates the activities of designers may satisfy the requirements.

Further, a design and build contractor may also be appropriate as principal designer, if they are involved in the project from an early stage, or if they take over the role of the principal designer at the point of contract and novation of the design team. But a contractor who has not been involved in the pre-construction phase is less likely to fulfil the requirements.

Due to the requirement under regulation 8 for the principal designer to possess the necessary skills, knowledge and experience and organisational capability to fulfil the role, a common trend is for clients to opt for appointing a ‘technical’ consultant from the design team such as the architect or engineer as principal designer, despite the wide range of other consultants being able to fulfil the role.

However, with this there is an underlying dilemma that begins to appear, as not every project team contains the multi-faceted organisation that is ideally suited to discharge the principal designer role. So faced with the real prospect of being singled out to fulfil the role, what can designers such as specialist architects and engineers do? Firstly they could refuse to take on such duties. Alternatively, they could acquire the expertise by adding staff with the appropriate experience and qualifications, or they can sub-contract out aspects of their role to specialist health and safety consultants. I will explore these questions in more depth below, after a brief consideration of the duties of the principal designer.

2. What must a principal designer do?

The CDM 2015 requires the principal designer to:

plan, manage and monitor the pre-construction phase and coordinate matters relating to health and safety during the pre-construction phase to ensure that, so far as is reasonably practicable, the project is carried out without risks to health and safety”.

However, it also imposes an obligation to “ensure” that “all persons working in relation to the construction phase cooperate with the client, the principal designer and each other”.

This is problematic, as the principal designer will have no means of compelling such performance. The principal designer will not have a contract with any of those individuals (other than the client) so will be powerless to force them to act.

One drastic solution is to put in place a multi-party interface agreement between each of the participants under which they have contractual rights to compel performance against each other. This is unlikely to be feasible or attractive in anything other than the most complex projects. Alternatively the client should be pressed to agree a reciprocal duty on its part, to ensure that all professional appointments and construction contracts contain obligations on the consultants and contractors to comply with their CDM responsibilities and co-operate with the principal designer. Then, if the principal designer meets with resistance from one of the delivery team, they can inform the client who will have the contractual muscle to compel performance of the non-compliant party.

3. Can a consultant refuse to be appointed as principal designer?

If the consultant is faced with the prospect of being appointed as principal designer, they have the option of refusing to assume the role. However, there are important considerations that must be borne in mind when this step is taken.

Aside from the risk of alienating their client, the statutory duty to appoint a principal designer on the construction project still exists; therefore it would be prudent for the consultant to clarify with the client precisely which member of the project team will be appointed as principal designer instead of their practice.

If the client does not appoint a principal designer, then in accordance with regulation 5(3) the client will assume the role. In such circumstances, the consultant should take proactive steps to assess whether the client has the necessary skills, knowledge and experience to fulfil those duties, then warn the client that they should appoint a principal designer if they do not.

By comparison, on domestic projects where a principal designer is required, if the client does not appoint a principal designer, the designer with control over the pre-construction phase will be deemed to be the principal designer even if not appointed in writing. As a result, it is very important to clarify who will be appointed, in order to avoid assuming the role by default.

4. Can you sub-contract the role of a principal designer?

The ‘sub-contracting out’ approach was not uncommon under the old Construction (Design and Management) Regulations 2007, where many project managers took on the role of CDM co-ordinator and appointed a sub-consultant to perform the duties.

However, this approach may fall foul of the designer’s professional indemnity insurance. Equally, the enhanced ‘designer’ requirements contained within the principal designer’s obligations as set out in regulation 8 may go beyond the expertise of many specialist health and safety consultants’ professional indemnity insurance cover and preclude them from fulfilling the role.

The most important issue with this approach is the fact that whilst it is possible to enter into a sub-consultancy appointment under which the sub-consultant will carry out the duties of a principal designer, the statutory role cannot be subcontracted. This means that the sub-consultancy will only pass on the civil liability in relation to the role, and not the potential criminal liability. Therefore it is important for a consultant to ensure that the sub-consultant has the sufficient skill to fulfil the requirements of the role. If you assume the role of principal designer and sub-contract it, the risk of fines or imprisonment in the event of a failure will remain with you rather than your sub-consultant.


In summary, the CDM 2015 moves the focus of health and safety on construction projects firmly towards the design, with duties imposed on a wide range of parties to continuously have one eye looking to the future when discharging their design obligations. The introduction of the principal designer role in particular is indicative of the intention through CDM 2015, to amend design at the heart of health and safety and vice versa.

As I have highlighted in this article, parties should strive to fully understand and be conscious of the duties of the principal designer, and the options and risks associated with refusing to accept, or sub-contracting the principal designer role.

Stanley Kamalu

Trainee Solictor 

Clarkslegal, specialist Construction lawyers in London, Reading and throughout the Thames Valley.
For further information about this or any other Construction matter please contact Clarkslegal's construction team by email at by telephone 020 7539 8000 (London office), 0118 958 5321 (Reading office) or by completing the form on this page.
This information is for guidance purposes only and should not be regarded as a substitute for taking legal advice. Please refer to the full General Notices on our website.

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