CDM Regulation Changes and the Principal Designer Role

The CDM regulations changed on 6th April 2015 with an objective to simplify the process to provide improved compliance and health and safety outcomes. Part of this change was the introduction of the Principal Designer role.

Outline of the CDM requirements

All Projects must have:

  • workers with the right skills, knowledge, training and experience (this is known as the competency criteria)
  • contractors providing appropriate supervision, instruction and information
  • a written construction phase plan

Projects where more than one contractor is involved must also:

  • appoint, in writing by the client, a Principal Designer and Principal Contractor
  • provide a health and safety file, for which the Principal Designer and Principal Contractor are responsible

Additionally all projects must be notified to the Health and Safety Executive if work is scheduled to:

  • last longer than 30 working days AND have more than 20 workers working simultaneously at any point in the project
  •  OR exceeds 500 person days

Key changes to the CDM regulations

Principal Designer

The Principal Designer will be the individual or organisation responsible for the pre-construction phase. The Principal Designer and the Client share the duties previously undertaken by the now redundant role of the CDM co-ordinator. The Health and Safety Executive state that the Principal Designer must ‘be a designer’, however they define a designer as an individual who is competent to either carry out or instruct others to perform the necessary design work.

This role is focused on the pre-construction phase but continues into construction phase where design work is modified, new design work is carried out and works are undertaken during the DLP. The Principal Designer also retains responsibility to ensure that other duty holders carry out their obligations throughout the contract, such as the provision of the health and safety file.

Although in practice the Client may delegate most functions, the responsibility to ensure they are implemented cannot be delegated. The client must satisfy themselves that the appointed designers and contractors have adequate levels of skill and experience, however there is no longer an explicit duty to check competence. The client retains full legal responsibility for the duties of the Principal Designer and Contractor if formal appointments are not made when required.

The Principal Designer role should not be confused with the role of an architect. The Principal Designer may not be directly responsible for the production of the physical design material and their role cannot be novated from the client to the Principal Contractor. The Principal Designer role always remains a direct appointment of the client.

Summary of functions for other Duty holders

Commercial clients:

Make appropriate arrangements for managing a project, including to ensure:

  • all other duty holders are appointed as appropriate
  • that sufficient time and resources are allocated
  • relevant information is prepared and supplied to other duty holders
  • that the PD and PC carry out their duties
  • adequate welfare facilities are provided

Principal Designers

Plan, manage, monitor and coordinate health and safety aspects during the pre-construction phase of a project. This includes:

  • identifying, eliminating or controlling foreseeable risks
  • ensuring designers carry out their duties
  • prepare and provide relevant information to other duty holders
  • liaising with the Principal Contractor to help in the planning, management, monitoring and coordination of the construction phase.


  • during design modifications, eliminate, reduce or control foreseeable risks that may arise during construction and post completion use
  • ensure good communication with other members of the project team

Principal Contractor

Plan, manage, monitor and coordinate health and safety aspects during the construction phase of a project. This includes:

  • liaising with the client and Principal Designer
  • prepare and distribute the construction phase plan
  • establish collaboration between contractors and coordinate their work
  • ensuring that suitable site inductions are provided, reasonable steps are taken to prevent unauthorised access, workers are consulted and engaged in securing their health and safety and that welfare facilities are provided


  • plan, manage and monitor construction work under their control so it is carried out without risks to health and safety.
  • for projects involving more than one contractor, coordinate their activities with others in the project team – in particular, complying with directions given to them by the Principal Designer or Principal Contractor.


Those working for or under the control of contractors on a construction site must:

  • be consulted about matters which affect their health, safety and welfare
  • take care of their own health and safety, and of others who might be affected by their actions
  • report anything they see which is likely to endanger either their own or others’ health and safety
  • co-operate with their employer, fellow operatives, contractors and other duty holders

To find out more information on our nationwide project management services, contact us today. You can either complete the enquiry form on our contact page or call one of our friendly team on 01423 611 604.


Skelton logo
Holland and Barrett logo
Nisbets logo
Hewden Logo
Travis perkins logo
Woodhead investments
Impala Estates
Empire cinemas logo
Currys logo
Connect housing logo
Clipper logo
Bucher Municipal logo
Motus logo
Smyths logo
Build a bear logo
GSF logo
National tyres logo
Halfords logo
Grafton logo
MKM logo
Next logo
BT logo
EE logo
Parts Alliance Logo
Barchester Logo
Anchor Logo Image
Booker Logo
XPO Logo
Portman Group - Portman Dental Care Logo
Formula One Autocentres Logo
GallifordTry Logo
Dunelm Logo
Dixons Carphone Logo
Last Cawthra Feather Logo
re'new Logo
Idexx Laboratories Logo
Schroders Logo
Travel West Midlands Logo
Cheque Centre Logo
Toolstation Logo
Inviron Logo
Careers Bradford Logo
National Trust Logo
TGI Fridays Logo
Speedy Hire Logo
Hyundai Logo
Thorntons Logo
Endsleigh Insurance Logo
Pizza Hut Logo
National Express Logo
Vodafone Logo
Nuffield Health Logo
Lush Cosmetics Logo
Speedy Cash Logo
TK Max Logo
Call Now Button