CDM 2015

The Construction (Design and Management) Regulations (CDM Regulations) are intended to ensure that health and safety issues are properly considered during a project's development so that the risk of harm to those who have to build, use and maintain structures is reduced.

They were introduced in 1994 following publication of European Directive 92/57/EEC on minimum safety and health standards for temporary or mobile construction sites. The CDM Regulations were revised in 2007, and the latest revision came into force on 6 April 2015.

The latest revision resulted from:

The perception that the regulations had been over-interpreted.
A belief that the coordination function in the pre-construction phase was often a bureaucratic add-on that was not always embedded in the project, resulting in additional costs with little additional value.
The persistence of unacceptable standards, particularly on smaller sites.

The regulations therefore made the following changes:

Structural simplification of the regulations to make them easier to understand.
The replacement of the Approved Code of Practice (ACOP) with more targeted guidance.
Replacement of the role of CDM coordinator with a new role of 'principal designer'.
Splitting competence assessment into its component parts of skills, knowledge, training and experience, and, if it relates to an organisation, organisational capability.
Removing the exemption for domestic clients, but passing their CDM duties to the contractor.
Changing the threshold for appointment of coordinators (principal contractors and principal designers), to require coordinators where there is more than one contractor. The Health and Safety Executive (HSE) suggested that this would capture close to an additional 1 million projects a year, but that the requirements would be proportionate and little more work would be necessary. Some concern was expressed about what constitutes more than one contractor, and how it is possible to know how many contractors may be needed.

These changes separate the threshold for coordination from that of notifying the HSE about the works. The HSE must be notified where the construction work is likely to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or exceed 500 person days.

In terms of the organisation of projects, the most significant of these changes is the replacement of the role of CDM coordinator with a new role of 'principal designer' (PD). The reason for the change is to give responsibility for CDM during the design phase to an individual that has the ability to influence the design. The role of principal designer is analogous to that of the principal contractor during the construction phase and includes:

Planning, managing and monitoring the pre-construction phase.
Ensuring risks are eliminated or controlled through design work.
Passing information on to the principal contractor.
Ensuring cooperation and coordination.
Ensuring designers comply with their duties.
Assisting the client in preparing pre-construction information.
Preparing the health and safety file.

Since 6 April 2024, a second and separate 'principal designer' role has applied under the Building Regulations dutyholder regime introduced by the Building Safety Act 2022. That regime took effect on 1 October 2023 and now applies to all building work in England, with enhanced duties for higher-risk buildings. The Building Regulations principal designer is responsible for planning, managing and monitoring compliance with the Building Regulations during the design phase, and is a distinct appointment from the CDM principal designer, although the same person or organisation may hold both roles where they have the necessary competence for each. Clients and design teams should take care not to conflate the two roles.

This change required the amendment of appointment documents and contracts.

Other duty holders under the regulations are:

Clients. (see CDM 2015 client duties)
Designers. (see CDM 2015 designer duties)
Principal contractors. (see CDM 2015 principal contractor duties)
Contractors. (see CDM 2015 contractor duties)
Workers. (see CDM 2015 worker duties)

A survey looking into the impact of CDM 2015 published by Construction Manager and Health and Safety at Work in May 2017 suggested that the principles of CDM 2015 were struggling to take root and that:

A workable system had been made less workable.
Fees and costs had increased without any increase in safety.
The goal of bringing smaller projects and domestic clients into scope had proved ineffectual.

Ref: Construction Manager, 18 May 2017.

In May 2026, the HSE published a review of CDM 2015 which concluded that the regulations remain fit for purpose and that their overall objectives continue to be met. No changes to the regulations themselves were recommended, though the HSE indicated it would improve supporting guidance on matters such as pre-construction information, client duties and the competence of principal designers, and would encourage wider use of digital systems for sharing project information.