CDM 2015
Duty Holder Guide

Principal Contractor

cdm 2015 Principal Contractor

CDM 2015 defines the principal contractor as the contractor in overall charge of the construction phase. The principal contractor is normally a contractor so will also have contractor duties, however, there should only be one principal contractor for a project at any one time.

Principal contractors have important duties under CDM, and must also take overall responsibility for the health and safety of all contractors on site. In this guide, we will take you through your responsibilities step-by-step. We will also link you to tools, resources and checklists to help you carry out your role.


The principal contractor is often the main contractor, and they are responsible for health and safety on site. The principal contractor must be capable of carrying out the role and have the right skills, knowledge, training and experience. This will depend upon the nature of the work and the range and nature of health and safety risks involved.

Any project with more than one contractor at any time (including subcontractors) needs a principal contractor, so this role is required on most construction projects. The principal contractor is appointed by the client, usually in writing, but appointment can also happen automatically on domestic projects.

The principal contractor is responsible for managing health and safety on the construction site and must plan, manage, monitor and coordinate the construction phase so that health and safety risks are controlled.

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Pre-Construction Phase
Before Construction Starts

The pre-construction phase is all the work that happens on a project before any work starts on site. This is the very earliest stage of a project and may also be referred to as the planning phase of the project. It's when designers and contractors are selected, and you plan and prepare for the project.

Liaise with the client and principal designer

You should check that the client is aware of their duties under CDM 2015, and work with the client and principal designer throughout the project. Early involvement gives you the opportunity to discuss construction methods and help designers consider health and safety in the design.

If the client is unfamiliar with construction projects, one of the first things you must do is make them aware of their client duties under CDM.

Establish what type of client you're working with, and remember that some client duties may transfer to you or the principal designer if you are working with a domestic client.

On projects that involve more than one contractor (including subcontractors), you must make sure the client has appointed a Principal Designer.

The principal designer is responsible for managing health and safety in the pre-construction phase of the project. Use your experience to discuss construction methods and share any information which may be relevant to considering health and safety in the design.

Where the project is notifiable, check that the client has completed and submitted an F10 notification. Use our free CDM notification calculator to check if the project needs to be notified.

Review the pre-construction information

The client must provide you with relevant information about the site, for example, surveys or the results of other investigations.

The pre-construction information should be provided to you in a clear, concise and convenient form containing information about:

  1. The project, including client expectations and key dates
  2. The planning and management, including resources and time allocated at each state
  3. Cooperation and coordination arrangements, including methods of communication
  4. Health and safety hazards of the site, including how design and construction hazards will be addressed
  5. Any relevant information from an existing health and safety file

The principal designer should help the client in putting this information together, and providing you with the pre-construction information pack. This information will help you plan the work and is the basis for developing your construction phase plan.

Prepare the construction phase plan

You must prepare a construction phase plan which describes how health and safety will be managed during the construction phase.

The pre-construction information you have received and any client requirements you have established will help in drawing up the construction phase plan.

The construction phase plan should be proportionate to the size and nature of the work, and the risks involved, workable and realistic, sufficiently developed to allow work to start on site and regularly reviewed and added to as new trades start.

The following topics should be considered in the construction phase plan:

  • Project information including description and key dates
  • Key members of the project team and contact information
  • Health and safety aims and expectations
  • Site rules
  • Arrangements for cooperation and coordination of work
  • Arrangements for involving workers
  • Site induction arrangements
  • Provision of welfare facilities
  • Fire and emergency procedures
  • Control of site safety risks
  • Control of site health risks

The principal contractor is responsible for preparing the construction phase plan before setting up the construction site and starting work.

You may need to update the plan with further information as it becomes available, but it is important to make sure that early issues such as mobilisation, site set-up, welfare and high risk activities are addressed in the plan before work starts.

Organise contractors work

The principal contractor must ensure all contractors and workers on site have the necessary skills, knowledge, training and experience for the work they are carrying out.

When appointing contractors it is important to make sure they have sufficient time to plan and resource their work before starting on site.

Ensure that contractors are aware of the time available for planning and preparation, and that they are provided with relevant information and instruction relevant to their works, including from the pre-construction information and construction phase plan.

The principal contractor should provide contractors with:

  • Details of key dates, including for preparation and lead times
  • Details of the project team including who is in charge of the site
  • Site rules and induction arrangements
  • Welfare facility arrangements
  • Details of any unusual or significant risks
  • Details of any sequence constraints
  • Emergency procedures
  • Arrangements for reporting - near miss, incidents, unsafe behaviours etc

Much of the above information can be provided in relevant pre-construction information and the construction phase plan.

Contractors should be given the opportunity to provide health and safety input at an early stage, and this will help you further develop the construction phase plan.

Contractors who will be working on site need to be involved in planning how they will carry out their work safely and with regard to health as early as is practicable.

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Construction Phase
When Work Starts On Site

The construction phase is when work that has been planned begins on site. It's when the site gets set up and the construction work could include demolition, maintenance and/or building activities.

Provide welfare facilities

The principal contractor is responsible for ensuring welfare facilities are provided and are suitable and sufficient for the size and nature of the site.

Welfare facilities must be available from the commencement of work on site and remain until the construction work is completed.

Existing facilities may be available and suitable. If not, a mixture of both existing and new, or temporary welfare facilities, will need to be provided on site.

Welfare facilities should include:

  • Toilets - lit and ventilated, suitable for men and women
  • Washing facilities - next to the toilets, including hot and cold running water, soap, and a way of drying hands
  • Supply of drinking water and cups
  • Facilities for rest including tables and chairs
  • Changing rooms and lockers where required

Welfare facilities must be regularly cleaned and have sufficient capacity for the expected number of workers on site.

Provide site inductions

The principal contractor must ensure a suitable site induction is provided to each site worker before they start work on the project.

The induction should be site specific and highlight any particular site risks and the control measures those working on the site need to know about. It should be relevant to the size and scope of the work, and level of risk involved.

The induction should include:

  • Project details
  • Management details and arrangements
  • Management commitment to health and safety
  • First aid arrangements
  • Accident and incident reporting requirements
  • Arrangements for health and safety briefings and toolbox talks
  • Consultation arrangements
  • Workers responsibilities
  • Site specific risks and arrangements

You should also provide site inductions to those who do not regularly work on the site, but visit occasionally or on a once only basis. You can tailor the induction to the nature of the visit, for example, if you will be escorting a visitor around the site, they will only need to be aware of the main hazards they may be exposed to and the control measures in place.

Manage the construction phase

The principal contractor has a duty to plan, manage and monitor the construction phase and coordinate matters relating to health and safety during the construction phase.

Planning of the works activities and identification of health and safety risks, control measures and resources needed to reduce or eliminate them is a continual process and should be carried out throughout the construction phase.

When planning, managing, monitoring and coordinating the construction phase, the principal contractor must take account of the general principles of prevention, particularly when decisions are being taken to plan items or stages of work sequences and estimating the time stages of work will take to complete.

Standards should be checked regularly by the principal contractor and prompt action taken where necessary. This may involve routine checks of work areas, and investigation of any near miss incidents.

The principal contractor must:

  • Make sure that anyone engaged to carry out work is capable of doing so safely
  • Ensure that effective health and safety measures are put in place to control the risks
  • Make sure the right plant, equipment and tools are provided to carry out the work

You should update your construction phase plan, and monitor site health and safety standards and control measures so that they remain effective.

Remember, as the principal contractor you have overall responsibility for health and safety on site during the construction phase. You should set an example and set standards for working practices on site.

The principal contractor must continue to liaise with the principal designer for the duration of the project on matters such as design changes and any implications on the management of health and safety. You should also start to provide any information requested by the principal designer for the health and safety file.

Secure the site

The principal contractor must ensure that reasonable steps are taken to prevent unauthorised access to the site.

You will need to cooperate with the client and others when working in occupied or shared premises to achieve this. Any occupiers will need to be made aware of your plans as their cooperation with the security arrangements will be important.

The site boundaries should be clearly marked out and physically defined with suitable barriers, depending on the size and nature of the project.

There will need to be special consideration and additional measures for sites with:

  • Adjacent sites
  • Other work areas next to them e.g. a shopping centre or offices
  • Occupied houses next to them e.g. new-build estates or work within a block of flats
  • Children or vulnerable people nearby e.g. schools or care homes
  • Access for members of the public e.g. a right of way through part of the site

Provide management and supervision

You must ensure that those managing and supervising the work have the right blend of skills, knowledge, training and experience and that there is an adequate number of supervisors.

Good supervision is essential for showing leadership in health and safety. It will help you to:

  • Focus workers attention on risks and preventing them
  • Show commitment to maintaining control measures
  • Consult with workers on site and take into account their views
  • Challenge unsafe conditions and behaviours on site

Through the actions of managers, the principal contractor can demonstrate health and safety leadership, and comply with the duty to ensure the construction phase plan is followed on site.

The supervisor should be familiar with the type of work planned. The level of supervision required should take into consideration the skills, knowledge, training, experience and likely behaviour of the workers.

Engage contractors and workers

It is a duty of the principal contractor to organise cooperation between contractors. You must ensure that contractors cooperate with each other so that risks to themselves and others are managed effectively.

Key information on health and safety risks including relevant parts of the construction phase plan needs to be shared with contractors and communicated with workers through induction and worker engagement.

You should ensure that contractors who start work at different stages cooperate with each other so that any information and instruction relevant to the new contractor is passed on to them so that they can work safely. This can be done through regular meetings and other less formal communication methods.

It is also a duty of the principal contractor to consult and engage with workers.

Consultation with workers is key to the successful management of health and safety on site. It should be a clear two-way process, giving an opportunity for both parties, or their safety representatives, to contribute to decision making.

Talk to workers about:

  • Risks arising from their work
  • Hazards and risks from the surrounding environment
  • Ideas for managing risks
  • Ways of providing information and training

Workers can provide valuable information by helping you identify risks on site, making sure controls are practical and providing ideas for improvement. Meaningful consultation with workers will also help raise commitment to health and safety.

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Post-Construction Phase
Project Completion

The post-construction phase is what happens at the end of the project. This may also be referred to as the handover phase of the project. It's when the construction work finishes and the project is signed-off and handed over the client.

Contribute to the health and safety file

As the principal contractor, you have a duty to provide the principal designer with any information in your possession relevant to the health and safety.

The principal designer is responsible for preparing the health and safety file and you need to provide them with any relevant health and safety information for inclusion in this document.

Requirements for the health and safety file, including its structure, content and format, should be identified before the construction phase and communicated by the principal designer.

The file contains the information needed to ensure the health and safety of anyone carrying out any future construction, demolition, cleaning or maintenance work on the building or structure.

Handover the health and safety file

On projects where the principal designer appointment finishes before the end of the construction phase, the principal contractor will take on the responsibility for the file and for handing it over to the client.

The principal designer should provide you with the file and information on the information outstanding at the end of their appointment. You will then have the responsibility for reviewing, updating and revising it, and handing the health and safety file over to the client when the project finishes.

Information should only be included in the file if it is needed to ensure the health and safety of anyone carrying out any future construction, demolition, use, cleaning or maintenance work on the building or structure.

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