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Ten keys to decipher the CDM 2015 regulations

Updated: Sep 25, 2023

CDM applies to all types of construction projects, no matter the scale or duration.

The Construction (Design and Management) Regulations (often referred to as CDM regulations) apply to every construction project in Great Britain. CDM applies to all types of projects including domestic. No matter how big or small. How short or long. CDM applies.

Here we'll look at 10 Key Points to remember, which hopefully will help you on your next project.

KEY #1

CDM applies to every construction project. If you are planning construction work or carrying out construction work, even for an hour, you MUST comply with CDM.

The CDM regulations were first introduced in 1994. They have been through a few changes since then, once in 2007, and again in 2015. While some of the requirements have been adjusted and developed, the overall aim stays the same. To improve health and safety in construction.

Construction is a high-risk industry. Every year people are killed, and thousands injured or made ill, through construction work. Proper planning of the work and careful assessment of the hazards involved are vital to ensure the safety of those on-site.

The purpose of the CDM regulations is to focus the attention of the project team on the health and safety aspects of the project, to improve the planning and management of projects, to facilitate the early identification of hazards, and to place responsibilities and efforts where they can most benefit health and safety.

KEY #2

Anyone appointed to work on a project MUST have the skills, knowledge, training and experience to carry out their role.

To achieve its objectives the CDM regulations place duties on everyone involved in construction work, particularly on key members of the project team such as the client, designers and contractors.

These key members of the project are known under CDM as dutyholders.


The Dutyholders required under CDM 2015 include:

  • Client

  • Principal Designer

  • Principal Contractor

  • Designers

  • Contractors

KEY #3

Know your duties. Each duty holder has their own duties that they MUST carry out under CDM.

Every dutyholder has their own duties under CDM. But they must also help other dutyholders, CDM is a team effort. Each dutyholder has a duty to cooperate and coordinate with other holders. In particular, the principal contractor is in overall control of the contractors and the construction phase. The principal designer is in overall control of designers and the pre-construction phase.

The CITB has produced industry guidance documents to help you understand the duties each dutyholder has these can be accessed via the following link:

KEY #4

The roles of principal designer and principal contractor MUST be appointed on any project with more than one contractor.

On most projects, the client will need to appoint a principal designer and principal contractor. These appointments should be made in writing. Failure to appoint these roles means the client has appointed themselves, and all the legal duties and responsibilities that go with it.

KEY #5

There can only be ONE principal designer and ONE principal contractor appointed on a project at any one time.

There may be occasions where two or more projects are taking place on the same site at the same time, but are run independently of one another. Whatever the circumstances, it is essential that there is clarity over who is in control during the construction phase in any part of the site at any given time. Where it is not possible for one principal contractor to be in overall control, those principal contractors involved must:

  • Cooperate with one another;

  • Coordinate their work; and

  • Take account of any shared interfaces between the activities of each project (eg shared traffic routes).

CDM Notification

Under CDM, some projects need to be notified to the HSE. This means that, in addition to carrying out your CDM duties, you must give notice of the project before work begins.

Projects lasting more than 500 person-days (or 30 working days with more than 20 workers) need to be notified.

KEY #6

Where a project is notifiable, the client MUST give notice in writing to the HSE using an F10 notification form as soon as is practicable before the construction phase begins.

The client must ensure that an up-to-date copy of the notice is displayed in the construction site office, so it is accessible to anyone working on the site and in a form that can be easily understood.

CDM Documents

In addition to the types of health and safety documentation you require under other health and safety regulations (policy, risk assessments, inductions etc) the CDM regulations place additional documentation requirements on construction projects. These are CDM specific documents, each needed at different stages of the project and for different reasons:

  • Pre-Construction Information

  • Construction Phase Plan

  • Health and Safety File

KEY #7

The pre-construction information MUST be provided by the client on every project.

Pre-construction information is defined as information about the project that is already in the client’s possession or which is reasonably obtainable by or on behalf of the client. The information must:

  • Be relevant to the particular project;

  • Have an appropriate level of detail; and

  • Be proportionate to the risks involved.

KEY #8

A construction phase plan MUST be developed for every construction project, by the principal contractor or sole contractor.

On every project, a construction phase plan must be developed, before work begins. The client has a duty to ensure this plan has been created, and the principal contractor has a duty to create it. On projects with only one contractor, they must produce the construction phase plan.

KEY #9

The principal designer MUST create and develop a health and safety file to handover on project completion.

The health and safety file is a document that is created throughout the project. Rather than being a document to manage health and safety during the project, this is one for the future. It contains health and safety information that may be needed to ensure the safety of those using, cleaning, maintaining or demolishing the building or structure after work is finished.

Site Requirements

Part 4 of the CDM Regulations sets out the general requirements for all construction sites.

A contractor carrying out construction work must comply with the requirements of this Part so far as they affect the contractor or any worker under the control of the contractor or relate to matters within the contractor’s control.

Part 4 covers a variety of construction site activities summarised as follows:

  • Regulation 17 Safe places of construction work

  • Regulation 18 Good order and site security

  • Regulation 19 Stability of structures

  • Regulation 20 Demolition or dismantling

  • Regulation 21 Explosives

  • Regulation 22 Excavations

  • Regulation 23 Cofferdams and caissons

  • Regulation 24 Reports of inspections

  • Regulation 25 Energy distribution installations

  • Regulation 26 Prevention of drowning

  • Regulation 27 Traffic routes

  • Regulation 28 Vehicles

  • Regulation 29 Prevention of risk from fire, flooding or asphyxiation

  • Regulation 30 Emergency procedures

  • Regulation 31 Emergency routes and exits

  • Regulation 32 Fire detection and fire-fighting

  • Regulation 33 Fresh air

  • Regulation 34 Temperature and weather protection

  • Regulation 35 Lighting

Additional information on these regulations can be found in the HSE guidance document L153 which can be accessed via the following link

KEY #10

Know the general requirements for construction sites under CDM for all tasks and activities relevant to your work.

Michael Coates CMIOSH is SHEQ Manager at Geotechnics Ltd & Vice Chair of the IOSH Manchester and North West District Branch.

He's a highly experienced Chartered Health & Safety Manager with over 13 years H&S experience, and almost 30 years' total experience in the construction sector.


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