In this post, we take a look at Principal Contractor Duties under CDM 2015.
Assuming the role of Principal Contractor can happen under various different circumstances. Firstly, let’s answer one of the most common questions we get asked – which projects require a Principal Contractor?
Which Projects require a Principal Contractor?
A principal contractor must be appointed in writing by the client where a project involves more than one contractor.

Who is a Principal Contractor?
A principal contractor is the contractor with control over the construction phase of a project involving more than one contractor. They are appointed in writing by the client (commercial or domestic) to plan, manage, monitor and coordinate health and safety during this phase.

Is a Principal Contractor important for construction Health and Safety?
A principal contractor, in close cooperation with the client and the principal designer, has an important role in influencing how the risks to health and safety are managed during construction work. This includes ensuring standards are understood and followed.
When should a Principal Contractor be appointed?
The principal contractor should be appointed by the client as early in the project as possible and before the construction phase begins. This is so that the principal contractor duties can be carried out in good time i.e.
- allow time to plan the work of the construction phase and, in liaison with the principal designer and others involved in the project, identify any risks to health and safety and the control measures which need to be put in place
- record details of any planning in a construction phase plan
- work with the client for the duration of their appointment
- liaise with the principal designer for the remainder of their appointment for the purposes of planning, managing, monitoring and coordinating the pre-construction phase
The effort devoted to planning should be proportionate to the complexity of the project and the level of risks involved.
What Competency does a Principal Contractor need?
A principal contractor must be able to demonstrate that they have the skills, knowledge, experience (SKE) and, where an organisation, the organisational capability to carry out the work they are being appointed for. The level of SKE should be proportionate to the scale and complexity of the project and the nature of the risks to health and safety.

Examples of demonstrating Competence (Skills, knowledge, experience) might include:
- records of continuing professional development (CPD) including training records
- membership of professional bodies
- references from previous construction work
Examples of demonstrating organisational capability might involve:
What you Must Do if you are Principal Contractor
A principal contractor is appointed by the client to control the construction phase of any project involving more than one contractor.
Principal contractors have an important role in managing health and safety risks during the construction phase so they must have the skills, knowledge, experience and, where relevant, organisational capability to carry out this work.
The principal contractor must:
- plan, manage, monitor and coordinate the entire construction phase
- take account of the health and safety risks to everyone affected by the work (including members of the public), in planning and managing the measures needed to control them
- liaise with the client and principal designer for the duration of the project to ensure that all risks are effectively managed
- prepare a written construction phase plan before the construction phase begins, implement, and then regularly review and revise it to make sure it remains fit for purpose
- have ongoing arrangements in place for managing health and safety throughout the construction phase
- consult and engage with workers about their health, safety and welfare
- ensure suitable welfare facilities are provided from the start and maintained throughout the construction phase
- check that anyone they appoint has the skills, knowledge, experience and, where relevant, the organisational capability to carry out their work safely and without risk to health
- ensure all workers have site-specific inductions, and any further information and training they need
- take steps to prevent unauthorised access to the site
- liaise with the principal designer to share any information relevant to the planning, management, monitoring and coordination of the pre-construction phase
Principal Contractor Duties | Downloads
Principal Contractor Duties for Domestic Clients
When working for a domestic client, the principal contractor will normally take on the client duties as well as their own as principal contractor.
If a domestic client does not appoint a principal contractor, the role of the principal contractor must be carried out by the contractor in control of the construction phase.


Alternatively, the domestic client can ask the principal designer to take on the client duties (although this must be confirmed in a written agreement) and the principal contractor must work to them as ‘client’ under CDM 2015.
Have a Question about Principal Contractor Duties?
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