A Principal Contractor is the party legally responsible for managing health and safety during the construction phase of a project notifiable under the Construction (Design and Management) Regulations 2015 (CDM 2015). They must be appointed in writing by the client before the construction phase begins. Their duties include preparing and maintaining the Construction Phase Plan, coordinating all contractors on site, ensuring adequate welfare facilities, and keeping an up-to-date site induction and training record. On projects with more than one contractor, a Principal Contractor must be appointed even if the project is not formally notifiable to the HSE.
What they do
- Prepare and maintain the Construction Phase Plan (CPP)
- Notify the HSE via the F10 online notification for notifiable projects
- Coordinate the activities of all contractors and subcontractors
- Ensure adequate welfare facilities are provided and maintained
- Conduct and record site inductions for all workers
- Manage site access control, exclusion zones and permit-to-work systems
- Liaise with the Principal Designer on pre-construction design hazards
- Maintain the site health and safety file and pass it to the client on completion
- Investigate and record accidents, near misses and dangerous occurrences
When you need one
A Principal Contractor must be appointed whenever a project involves more than one contractor - whether or not it reaches the HSE notification threshold.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Principal contractor fee | Included in build contract |
| Construction Phase Plan preparation | £800 - £2,000 |
| HSE F10 notification (online) | Included |
| CDM compliance audit | £600 - £1,500 |
| Site safety management plan | £500 - £1,200 |
| Hourly rate | £70 - £120 / hr |
The Principal Contractor's fee is normally embedded in the build contract price. Standalone Construction Phase Plan preparation and CDM advisory services are charged separately where a specialist CDM consultant is engaged.
Qualifications to look for
The primary professional qualification for construction managers in the UK. MCIOB members have demonstrated competence in managing construction projects including health and safety obligations. Check membership at ciob.org.
Health and safety qualifications specifically relevant to the CDM Principal Contractor role. The NEBOSH Construction Certificate is the industry benchmark for site management.
Frequently asked questions
What is a Principal Contractor?
The Principal Contractor is the organisation or individual in overall control of a construction site who takes on the CDM duties including producing a Construction Phase Plan, coordinating all contractors, and ensuring welfare facilities are provided.
Who can be a Principal Contractor?
Any individual or organisation that manages or controls the construction phase can be appointed as Principal Contractor. They must be competent to manage the health and safety of the project and must not be appointed until the Construction Phase Plan is prepared.
What is the difference between a Principal Contractor and a Principal Designer?
The Principal Designer manages health and safety during the pre-construction (design) phase. The Principal Contractor manages health and safety during construction. On small projects the same person may fulfil both roles, but this requires competence in both disciplines.