The Principal Designer is a statutory duty holder created by the Construction Design and Management Regulations 2015 (CDM 2015). On notifiable construction projects - those lasting more than 30 working days with more than 20 workers simultaneously on site, or exceeding 500 person-days - the client must appoint a Principal Designer before construction begins. The Principal Designer's role is to coordinate health and safety in the design phase, eliminate hazards so far as reasonably practicable, and ensure that the Principal Contractor has the information they need before work starts. The same firm or individual often acts as both lead designer and Principal Designer on smaller projects.
What they do
- Pre-construction health and safety coordination across the design team
- Hazard identification and elimination in the design process
- Pre-construction information pack preparation and distribution
- Health and safety file compilation and handover to client
- Liaison with Principal Contractor on CDM matters
- CDM notification to HSE (F10 form submission)
- Design risk register preparation and maintenance
When you need one
A formally appointed Principal Designer is required on notifiable projects. The triggers below are those that make a project notifiable - if any apply, a Principal Designer must be appointed before construction starts.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| CDM coordination (small notifiable project) | £800 - £2,000 |
| CDM coordination (medium project) | £2,000 - £5,000 |
| Pre-construction information pack | £400 - £900 |
| Health and safety file | £300 - £700 |
| Hourly rate | £75 - £130 / hr |
Where the architect or lead consultant already holds CDM competence, the Principal Designer fee may be rolled into their overall design fee rather than charged separately. Always check whether CDM coordination is included in your lead consultant's appointment.
Qualifications to look for
The APS is the professional body for health and safety in the design and management of construction projects. MAAPS (Member) and FAAPS (Fellow) demonstrate competence specifically in CDM coordination and Principal Designer roles. Check at aps.org.uk.
Many Principal Designers are qualified construction professionals - chartered builders, architectural technologists or surveyors - who have developed CDM competence as a specialism. The underlying professional qualification plus APS membership is a strong combination.
A widely recognised health and safety qualification relevant to construction. The NEBOSH Construction Certificate is often the minimum standard expected for CDM coordination roles, particularly on smaller projects.
How to find a reputable Principal Designer
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Does every building project need a Principal Designer?
No. Only notifiable projects require a formally appointed Principal Designer. A project is notifiable to the HSE if it will last more than 30 working days with more than 20 workers simultaneously on site at any point, or if it will exceed 500 person-days in total. However, the CDM duties on designers apply to all projects - the Principal Designer role is specifically for notifiable projects with more than one contractor.
Can my architect be the Principal Designer?
Yes. Architects frequently act as Principal Designer on notifiable projects because they are already the lead designer and are well-placed to coordinate design-phase health and safety. However, the architect must have the skills, knowledge, experience and organisational capability to fulfil the role. If they lack CDM competence, a specialist CDM consultant should be appointed alongside them.
What is CDM?
CDM stands for the Construction Design and Management Regulations 2015. They impose legal duties on clients, designers and contractors to plan, manage and monitor health and safety throughout all stages of a construction project. The regulations replaced earlier CDM versions and introduced the Principal Designer role to replace the former CDM Coordinator.