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Duties of Principal Designer

CDM (GB) Knowledge Base


Although ultimately a 'designer' under the CDM2015 regulations, there are additional duties as a Principal Designer. Regulation 11 sets out the duties a principal designer has during the pre-construction phase. They include requirements to plan, manage, monitor and coordinate the work of the phase and to liaise with the principal contractor in providing information relevant for the planning, management and monitoring of the construction phase.

Who is a Principal Designer?

A principal designer is the designer with control over the pre-construction phase of the project. This is the very earliest stage of a project from concept design through to planning the delivery of the construction work. The principal designer must be appointed in writing by the client to carry out their duties.

The principal designer is an organisation (or on a smaller project they can be an individual) that has:

  1. a technical knowledge of the construction industry relevant to the project;
  2. the understanding and skills to manage and coordinate the preconstruction phase, including any design work carried out after construction begins.

Where the principal designer is an organisation they should have the organisational capability to carry out the role as well as the necessary skills, knowledge and experience that individual designers must have.

Principal designers may well have separate duties as designers on a project, for more information go to Duties of Designers.

Why is the principal designer important?

In liaison with the client and principal contractor, the principal designer has an important role in influencing how the risks to health and safety should be managed and incorporated into the wider management of a project. Decisions about the design taken during the pre-construction phase can have a significant effect on whether the project is delivered in a way that secures health and safety. The principal designer's role involves co-ordinating the work of others in the project team to ensure that significant and foreseeable risks are managed throughout the design process.

Planning, managing, monitoring and coordinating

In carrying out the duty to plan, manage, monitor and coordinate the preconstruction phase, principal designers must take account of:

  1. the general principles of prevention and, where relevant, the content of:
  2. any construction phase plan (see Appendix 3 of the CDM2015 guidance). This will be relevant when the plan has implications for any design work that is carried out after the construction phase has started e.g. ground contamination discovered affecting the choice of piling method; and
  3. any existing health and safety file (see Appendix 4). In cases where a health and safety file has been prepared as part of previous construction work on the building, the file should have information which will help the planning, management and coordination of the pre-construction phase.

This information should be taken into account, in particular, when decisions are being taken about design, technical and organisational issues in order to plan which items or stages of work can take place at the same time or in sequence; and when estimating the time needed to complete certain items or stages of work.

The principal designer's work should focus on ensuring the design work in the pre-construction phase contributes to the delivery of positive health and safety outcomes. Bringing together designers as early as possible in the project, and then on a regular basis, to ensure everyone carries out their duties will help to achieve this. This can be done as part of the normal design process. Regular design meetings chaired by the principal designer are an effective way to:

  1. discuss the risks that should be addressed during the pre-construction phase;
  2. decide on the control measures to be adopted; and
  3. agree the information that will help in preparing the construction phase plan.

When appointing any designers, the principal designer must check that these designers have sufficient skills, knowledge, experience and (if they are an organisation) the organisational capability to carry out the work. These checks should be carried out before appointment takes place.

The principal designer's role continues into the construction phase when design work is carried out and when gathering and preparing information for the health and safety file.

Identifying, eliminating or controlling foreseeable risks

Principal designers must ensure, as far as is reasonably practicable, that foreseeable risks to health and safety are identified. In practice, this will involve the principal designer working with other designers involved with the project. The risks that should be identified are those that are significant and are likely to arise:

  1. while carrying out construction work; or
  2. during maintenance, cleaning or the use of the building as a workplace once it is built.

Once the risks have been identified, principal designers must follow the approach to managing them set out in the general principles of prevention. The principal designer must, as far as reasonably practicable, ensure that the design team:

  1. Eliminate the risks associated with design elements. If this is not possible (for instance because of competing design considerations such as planning restrictions, specifications, disproportionate costs or aesthetics):
  2. Reduce any remaining risks; or
  3. Control them, to an acceptable level. This relies on exercising professional judgement in considering how the risks can be managed. The focus should be on those design elements where there is a significant risk of injury or ill-health.

Ensuring coordination and cooperation

Principal designers must ensure that:

  1. Everyone involved in working on the pre-construction phase cooperates with each other. They must establish that effective communication is occurring and that information is shared within the project team. This could involve holding meetings with others in the design team. Progress meetings with the client and the principal contractor also provide a way of ensuring work on the project is properly coordinated;
  2. Designers comply with their duties (see designer duties). Appropriate checks should be made to ensure that designers are dealing with design risks appropriately. This can be done as part of the design process and through regular progress meetings;
  3. Designers are providing information about elements of the design which present significant risks that cannot be eliminated. This should include information about unusual or complex risks that are more likely to be missed or misunderstood by contractors or others on the project rather than risks that are well-known and understood.

Providing pre-construction information

Pre-construction information is defined as information that is already in the client's possession or which is reasonably obtainable. It must be relevant, have an appropriate level of detail and be proportionate given the nature of risks to health or safety involved in the project.

The client has the main responsibility for pre-construction information. However, the principal designer must help and advise the client. The principal designer should help the client bring the information the client already holds (such as any existing health and safety file or asbestos survey) together. The principal designer should then:

  1. assess the adequacy of existing information to identify any gaps in the information which it is necessary to fill; and
  2. provide advice to the client on how the gaps can be filled and help them in gathering the necessary additional information.
  3. provide, as far as they are able to, the necessary information promptly and in a convenient form to help designers and contractors who:
    • are being considered for appointment; or
    • have already been appointed, to carry out their duties.

Further guidance on the requirements relating to the preconstruction information can be found in Appendix 2 of the CDM2015 guidance.

Liaising with the principal contractor

The principal designer must liaise with the principal contractor for the duration of their appointment. During the pre-construction phase this must cover sharing information that may affect the planning, management, monitoring and coordination of the construction phase - in particular, the information needed by the principal contractor to prepare the construction phase plan. Liaison should also extend into the construction phase to deal with on-going design and obtaining information for the health and safety file. This could be done by holding regular progress meetings with the principal contractor.

If the principal designer's appointment finishes before the end of the project, the principal designer must ensure that the principal contractor has all the necessary information so that they:

  1. are aware of the risks which have not been eliminated in the designs;
  2. understand the means employed to reduce or control those risks; and
  3. understand the implications for implementing the design work during the remainder of the project.

The principal designer should also arrange for a handover of the health and safety file to the principal contractor and make them aware of any issues that may need to be taken into account in reviewing, updating and completing it.

Working for domestic clients

A principal designer's role when working on a project for a domestic client is no different to the role undertaken for a commercial client. More information about domestic client can be found in the Domestic Clients topic.