On this page
- When is a Principal Contractor required?
- What must a Principal Contractor be able to demonstrate?
- What are the Principal Contractor's duties under CDM 2015?
- How do these duties work on site?
- What is the difference between Principal Contractor and contractor duties?
- What are the most common Principal Contractor failings?
- What about the Building Regulations Principal Contractor?
- Need support meeting Principal Contractor duties?
Principal Contractor duties under CDM 2015 centre on one requirement: to plan, manage, monitor and coordinate health and safety during the construction phase of a project with more than one contractor. That includes preparing the Construction Phase Plan, organising cooperation between contractors, making sure workers are inducted, providing welfare, preventing unauthorised access and consulting the workforce.
The Principal Contractor is the dutyholder that controls the site. This guide explains when a Principal Contractor is needed, what the regulations actually require and how those duties translate into practical site management.
When is a Principal Contractor required?
Under the Construction (Design and Management) Regulations 2015, the client must appoint a Principal Contractor where there is, or is likely to be, more than one contractor working on the project. The appointment must be in writing and made as soon as practicable, before the construction phase begins.
The requirement does not depend on:
- The value of the project
- Whether the project is notifiable to HSE using an F10
- Whether the client is commercial or domestic
If a commercial client fails to appoint a Principal Contractor, the client must carry out the Principal Contractor's duties itself. On domestic projects, the contractor in control of the construction phase becomes the Principal Contractor unless other written arrangements are made.
What must a Principal Contractor be able to demonstrate?
Before accepting the appointment, a Principal Contractor must have the skills, knowledge and experience to carry out the role. As an organisation it must also have the organisational capability to do so in a way that secures health and safety. This requirement comes from regulation 8 of CDM 2015 and applies to every dutyholder. We cover it in detail in our guide to competence under CDM 2015.
What are the Principal Contractor's duties under CDM 2015?
The Principal Contractor's specific duties are set out mainly in regulations 12, 13 and 14, with general duties in regulation 8. HSE's guidance, L153, explains how they should be applied.
Plan, manage, monitor and coordinate the construction phase
This is the core duty. The Principal Contractor must plan, manage, monitor and coordinate matters relating to health and safety during the construction phase so that construction work is carried out without risks to health or safety, so far as is reasonably practicable. In doing so it must take account of the general principles of prevention and, where relevant, work that is carried out at the same time or in sequence.
Prepare the Construction Phase Plan
The Principal Contractor must draw up a Construction Phase Plan during the preconstruction phase, before setting up the site. The plan must set out the health and safety arrangements and site rules. It must include specific measures for any work with particular risks listed in Schedule 3 of the regulations. It must be reviewed, updated and revised throughout the project. See our guide to the Construction Phase Plan.
Organise cooperation between contractors
The Principal Contractor must organise cooperation between contractors, including successive contractors on the same site. It must also coordinate their work. In practice this is about sequencing, interfaces, shared areas, shared plant and making sure one contractor's work does not create risks for another.
Ensure employers and contractors apply the general principles of prevention
The Principal Contractor must ensure that employers and self employed people apply the general principles of prevention consistently and follow the Construction Phase Plan.
Ensure a suitable site induction is provided
Every worker must receive a suitable site induction. The induction should cover the site specific risks, rules, emergency arrangements and welfare, not simply repeat general construction safety content.
Prevent unauthorised access
The Principal Contractor must take the necessary steps to prevent access to the site by unauthorised persons. That usually means site boundaries, controlled access points and sign in arrangements. It also covers protecting the public where the site sits next to live roads, footpaths or occupied buildings.
Provide welfare facilities
The Principal Contractor must make sure welfare facilities that meet the minimum requirements in Schedule 2 of CDM 2015 are provided throughout the construction phase. That covers toilets, washing facilities, drinking water, changing rooms and lockers, plus facilities for rest.
Liaise with the Principal Designer
The Principal Contractor must liaise with the Principal Designer for the duration of the Principal Designer's appointment. This includes sharing information relevant to the planning and management of the preconstruction phase and to the health and safety file. It also means coordinating design changes that affect the construction phase.
Provide information for the health and safety file
The Principal Contractor must provide the Principal Designer with any information in its possession relevant to the health and safety file. Where the Principal Designer's appointment ends before the project is finished, the Principal Contractor takes over responsibility for reviewing, updating and revising the file and passing it to the client at the end of the project.
Consult and engage with workers
Regulation 14 requires the Principal Contractor to make and maintain arrangements that enable it and the workers to cooperate in developing, promoting and checking the effectiveness of health and safety measures. It must consult workers or their representatives in good time on matters affecting their health, safety or welfare. It must also make sure they can inspect and take copies of relevant information. See our guide to construction toolbox talks for one practical way this is delivered.
How do these duties work on site?
The regulations describe what must be achieved rather than exactly how. On a typical project the Principal Contractor's duties are delivered through a set of practical arrangements:
- Mobilisation: Construction Phase Plan, site set up, welfare, security, emergency arrangements and logistics in place before work starts
- Contractor selection: checks that subcontractors have the competence and resources for their packages
- Preconstruction meetings: agreeing method, sequence and interfaces with each contractor
- RAMS review: checking each contractor's method before work starts. See RAMS review
- Induction and briefing: site induction for everyone and task briefings on RAMS
- Permit systems: controlling high risk activities such as hot works, excavations, confined spaces and live services
- Temporary works control: a procedure in line with BS 5975, usually through the Principal Contractor's Temporary Works Coordinator
- Coordination: daily and weekly coordination meetings, lookahead planning and interface control
- Monitoring: supervision, site inspections, audits and close out of findings
- Worker engagement: consultation, toolbox talks and routes for raising concerns
- Incidents: reporting, investigation and RIDDOR where required
- Handover: information for the health and safety file
What is the difference between Principal Contractor and contractor duties?
Every contractor, including the Principal Contractor, has its own duties under regulation 15 of CDM 2015. Contractors must plan, manage and monitor the work under their control, provide supervision, instructions and information to their workers. They must also comply with the Principal Contractor's directions and the Construction Phase Plan.
The Principal Contractor's extra duties relate to the construction phase as a whole. Contractors control their own work. The Principal Contractor controls how all the work fits together.
What are the most common Principal Contractor failings?
- Generic Construction Phase Plans that do not reflect the project
- Subcontractor RAMS accepted without meaningful review
- Poor coordination between trades working in the same area
- Inductions that are generic or not given to every worker
- Welfare not in place from the first day on site
- Weak control of site boundaries next to public areas
- Monitoring carried out but findings not closed out
- Temporary works not controlled through a proper procedure
- Health risks such as dust given less attention than safety risks
HSE's enforcement activity on construction sites regularly focuses on exactly these points. A notification of contravention can also lead to charges under Fee for Intervention.
What about the Building Regulations Principal Contractor?
Since October 2023 projects in England may also have a Principal Contractor under the Building Regulations, with duties relating to compliance of the building work rather than health and safety. The roles share a name but are legally separate. See CDM 2015 and Building Regulations dutyholders.
Need support meeting Principal Contractor duties?
Matthews & Roberts supports Principal Contractors with Construction Phase Plans, RAMS review, subcontractor coordination, site inspections and CDM advice throughout the construction phase.
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Frequently asked questions
When is a Principal Contractor required under CDM 2015?
A Principal Contractor is required on any project where there is, or is likely to be, more than one contractor. The client must appoint the Principal Contractor in writing as soon as practicable before the construction phase begins. The requirement does not depend on the size of the project or whether it is notifiable to HSE. If the client fails to appoint one, the client must carry out the Principal Contractor's duties itself.
What happens if a domestic client does not appoint a Principal Contractor?
On domestic projects with more than one contractor, the client's duties normally pass to the contractor in control of the construction phase. If a domestic client does not appoint a Principal Contractor, the contractor in control of the construction phase becomes the Principal Contractor. A domestic client can instead agree in writing for the Principal Designer to take on the client duties.
Is the Principal Contractor responsible for subcontractors' health and safety?
The Principal Contractor is responsible for planning, managing, monitoring and coordinating health and safety during the construction phase, including how contractors work together. Each subcontractor remains responsible for its own work and workers under its own duties as an employer and contractor. The Principal Contractor does not take over those duties, but it must organise cooperation, check arrangements are suitable and act when they are not followed.
Can the client be the Principal Contractor?
Yes, if the client has the skills, knowledge, experience and organisational capability to carry out the role, it can take on the Principal Contractor duties. If a commercial client fails to appoint a Principal Contractor on a project with more than one contractor, the law treats the client as having to fulfil those duties anyway. In practice most clients appoint the main contractor.
Do Principal Contractor duties apply to small projects?
Yes. The duties apply to every project with more than one contractor, however small. What changes on a small project is the level of detail needed. A short refurbishment may need only a brief Construction Phase Plan and simple arrangements, but the planning, induction, welfare, security and coordination duties still apply.
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