CDM 2015 Regulations – Summary of the changes


This article provides a brief summary of eight key changes to the CDM 2015 Regulations from CDM 2007 and what those changes mean in practice

In this article, Mike Webster provides a brief summary of eight key changes to the CDM 2015 Regulations from CDM 2007 and what those changes mean in practice.

The Construction (Design and Management) Regulations (CDM) are the primary regulations for managing the health, safety and welfare of all construction projects in Great Britain.  CDM 2007 has been replaced, and CDM 2015 came into force on 6 April 2015.

Key changes to the CDM 2015 Regulations from CDM 2007 are:

1. The CDM 2015 Regulations have a simplified structure

The regulations provide now contain a more linear structure that mirrors the process of delivering a construction project from concept, through design and construction to handover and future use of the structure.  The types of duty holder (Client, Principal Designer, Principal Contractor, Designer and Contractor) on a project will be the same for most projects except the very smallest (those with only one Contractor on them).

2. Clients’ responsibilities have been strengthened and broadened

The Client is now responsible for making the arrangements by which the project will be managed and ensuring that those arrangements are maintained and reviewed throughout the life of the project.  Under CDM 2007, the Client only had to take reasonable steps to ensure that the arrangements made were suitable and subsequently maintained and reviewed.

The Client is also responsible for taking ‘reasonable steps’ to ensure:

  • Both the Principal Designer and Principal Contractor comply with their duties
  • Pre-construction information is provided ‘as soon as is practicable’ to every Contractor and Designer appointed or considered for appointment
  • The construction phase plan and health and safety file are produced
  • The health and safety file is handed over to any new owner of the structure

3. The exemption for Domestic Clients has been removed

Although the exemption for Domestic Clients has been removed in CDM 2015, the only responsibilities placed upon them are to appoint the Principal Contractor and Principal Designer, where there is more than one contractor.  However, if the Domestic Client does not make these appointments, CDM 2015 automatically transfers the Client duties to the Contractor or Principal Contractor.

4. The role of CDM Coordinator has been removed

However, if the CDM Coordinator had already been appointed before 6 April 2015, the Client must appoint a Principal Designer to replace the CDM Coordinator by 6 October 2015, unless the project comes to an end before then.  This process is described in the transitional arrangements in Schedule 4 of CDM 2015.

5. The new role of Principal Designer has been introduced to plan, manage, monitor and coordinate the pre-construction (design) phase

This new role brings the function of planning, managing, monitoring and coordinating the design phase of the project, directly into the project team and under the control of a Designer.  The duties of planning, managing, monitoring and coordinating mirror those of the Principal Contractor during the construction phase.  This role is not limited to the design phase before construction starts, but carries on whilst design is still being undertaken (e.g. the design of temporary works).

The Principal Designer is responsible for ensuring that the Designers working on the project discharge their Designer duties throughout their appointment.

The Principal Designer will:

  • Support the Client in bringing together and providing the pre-construction information and act as the channel for disseminating that information at the right time to those dutyholders who will need it
  • Work together with the Principal Contractor throughout the life of their appointment to ensure the health and safety implications of design aspects and later changes are properly considered
  • Support the Principal Contractor in drawing up the construction phase plan
  • Support the Principal Contractor in developing the health and safety file and providing it to the client at the end of the project

6. Notification of the project to the Health and Safety Executive (HSE) has been removed as a trigger point for additional duties

Under CDM 2007, these additional duties included the appointment of a CDM Coordinator and Principal Contractor along with the preparation of a construction phase plan and health and safety file.

All projects now require a construction phase plan under CDM 2015.  All projects requiring more than one contractor now require a health and safety file under CDM 2015.

7. The threshold for appointing a Principal Designer and Principal Contractor is if more than one Contractor is required on a project

This has replaced notification as the threshold, and means that all bar the very smallest projects will require a Principal Designer and Principal Contractor.

8. The requirement for ‘competence’ has been removed and replaced with ‘skills, knowledge, experience and training’ and ‘organisational capability’

The evaluation of CDM 2007 noted that competency checks had introduced a new ‘industry’ and had led to bureaucracy.  CDM 2015 has split ‘competence’ into its component parts of ‘skills, knowledge, training and experience’ and, where it refers to an organisation, ‘organisational capability’.

Further information

A series of published discussions on key issues and answers to frequently asked questions are collected together in this post.

Detailed clause-by-clause comparisons of the changes between the CDM 2015 Regulations and CDM 2007 are available on the MPW R&R web site for Clients, Designers and Principal Contractors / Contractors.

A series of articles providing information on key issues regarding the CDM 2015 Principal Designer duties are collected together for ease of use in this post.

I gave a 25-minute presentation at the Institution of Structural Engineers Small Practitioners Conference on 26 June 2018 on understanding the CDM 2015 Designer Duties as they relate to civil and structural engineers.  The video of my presentation and the accompanying slides are available in this post.

An overview of the issues involved in CDM 2015 Designer Duties – Designing for maintenance are discussed in this post and the guidance available to civil and structural engineers on contemporary industry practice is highlighted.

The HSE web site contains a range of information on CDM 2015 including the guidance on the regulations, a short guide for clients and a guide on construction phase plans.

The CITB web site contains industry guidance for each of the duty holders.

About the author:

Dr Mike Webster is a chartered civil and structural engineer with over 30 years’ experience.  He specialises in construction and structural safety, CDM and risk, and founded MPW R&R to provide Consulting, Forensic and Expert Witness services in those areas.

Mike has worked on the design, inspection, appraisal and site supervision of building, bridge and car park structures.  He has developed guidance for assessing the safety of existing structures.  Mike led an independent review of CDM 1994 and the independent evaluation of CDM 2007.  He also led the review of the use of CDM 2007 in the construction of London 2012.

Mike has been instructed as an expert witness by both defence and prosecution teams in cases involving allegations of gross negligence manslaughter, breaches of the Health and Safety at Work Act and the CDM Regulations and the appeal of enforcement notices.  These cases have involved the construction, maintenance and demolition of a range of building, bridge and industrial structures.

Mike is the author of around 20 published reports and papers on construction health and safety and the CDM Regulations.  He is also the author of a range of articles on CDM 2015.   He is a member of Structural-Safety and the Institution of Structural Engineers Health and Safety Panel.

For more information email Mike at or give him a call on 07969 957471.

One comment on “CDM 2015 Regulations – Summary of the changes
  1. Mandi Holt says:

    Thank you very much for posting this up. Very helpful and concise.

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