30/04/2026
CDM Regulations 2015 Explained – Duties, Roles and Compliance
Written By: enevo
Estimated Time: 15 mins
Building Safety
What are the CDM regulations?
The Construction (Design and Management) Regulations 2015, commonly known as CDM 2015, set out legal duties for managing health and safety on construction projects in Great Britain.
CDM 2015 applies to construction work of all sizes, from smaller refurbishments to major developments. It is not only about site safety. The regulations cover planning, design coordination, information, risk management and safe working throughout a project.
HSE’s guidance explains that CDM is intended to help project teams plan work sensibly, appoint the right people, coordinate their activities and provide the information needed to manage risks.
CDM 2015 came into force on 6 April 2015, replacing the previous CDM 2007 regulations.
Who do CDM 2015 regulations apply to?
CDM 2015 applies to construction work and the people or organisations involved in it, including:
- Commercial clients
- Domestic clients
- Designers
- Principal Designers
- Principal Contractors
- Contractors
- Workers
It also applies to domestic projects. Where construction work is carried out on behalf of a domestic client, the client’s duties are normally transferred to other dutyholders depending on how the project is organised. HSE distinguishes this from a householder carrying out the work themselves as DIY, where CDM 2015 does not apply.
What counts as construction work under CDM?
CDM covers a wide range of construction activities, including:
- New build construction and extensions
- Refurbishment, repair and maintenance
- Demolition and site preparation
- Structural alterations and fit-out
- Installation or removal of fixed services
This means a project does not have to be a major development to fall within CDM 2015.
What are the CDM dutyholder roles and responsibilities?
| Dutyholder | Main responsibility |
|---|---|
| Commercial client | Make suitable arrangements for managing the project, appoint appropriate dutyholders and provide sufficient time, resources and information. Make sure the Principal Designer and Principal Contractor carry out their duties and welfare facilities are provided. |
| Domestic client | Client duties normally pass to the contractor on a single-contractor project or the Principal Contractor on a project involving more than one contractor. The domestic client can instead agree in writing that the Principal Designer will carry out the client duties. |
| Designer | Eliminate, reduce or control foreseeable risks through design and provide relevant information to others. |
| Principal Designer | Plan, manage, monitor and coordinate health and safety during the pre-construction phase on projects involving, or likely to involve, more than one contractor. |
| Principal Contractor | Plan, manage, monitor and coordinate health and safety during the construction phase on projects involving, or likely to involve, more than one contractor. |
| Contractor | Plan, manage and monitor the construction work under their control and coordinate with others. On single-contractor projects, prepare the Construction Phase Plan. |
| Workers | Take reasonable care, cooperate with others and report matters that could affect health and safety. |
HSE’s current summary of duties provides the detailed responsibilities for each role.
What does a Principal Designer do under CDM 2015?
The CDM Principal Designer is a designer with control over the pre-construction phase, appointed by the client on a project involving, or likely to involve, more than one contractor.
Their role is to lead the planning, management, monitoring, and coordination of health and safety during the pre-construction phase. This includes coordinating designers, identifying foreseeable risks and providing relevant information to other dutyholders. The Principal Designer should be appointed as early as possible in the design process, where practicable at concept stage.
The role can continue into the construction phase where design work or design-related issues remain relevant. The Principal Designer also has responsibilities relating to the Health and Safety File.
For projects requiring specialist support, see enevo’s CDM Principal Designer and Advisory Services.
What documents are required under CDM 2015?
CDM 2015 requires project information and planning to be managed throughout the work. Key documents and information include:
Pre-Construction Information (PCI) – information about the project, site and existing risks that is relevant to those planning and carrying out the work.
Construction Phase Plan – the plan for managing health and safety during the construction phase. A Construction Phase Plan must be drawn up before setting up the construction site, including on single-contractor projects. The Principal Contractor must prepare it, or arrange for it to be prepared, on projects involving more than one contractor; the contractor has this responsibility on single-contractor projects.
Health and Safety File – information that should be retained and handed over for future construction work, maintenance, cleaning, alteration or demolition. A Health and Safety File is required for projects involving more than one contractor.
F10 notification – certain projects must be notified to HSE. HSE provides specific guidance on when notification is required and how it should be made.
When is a construction project notifiable?
A project must generally be notified to HSE where the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or where the total project involves more than 500 person-days of construction work.
CDM 2015 and the Building Safety Act
In England, CDM 2015 and the building regulations dutyholder regime are separate requirements, although projects may need to address both.
The CDM Principal Designer is responsible for planning, managing, monitoring and coordinating health and safety during the pre-construction phase under CDM.
The Building Regulations Principal Designer has a different role relating to compliance with building regulations. The Building Safety Regulator confirms that the roles have different functions and competence requirements, although the same organisation can undertake both roles where the relevant requirements are met. Where the same organisation carries out both roles in England, the client must confirm this in writing to those appointed.
For projects subject to both regimes, the roles need to be clearly understood and relevant information coordinated without blurring the separate legal responsibilities.
How should CDM compliance be managed through a project?
Design and pre-construction: establish the dutyholder structure, gather pre-construction information, identify foreseeable risks and coordinate design decisions.
Construction: make sure the Construction Phase Plan and site arrangements reflect the work being undertaken, with appropriate coordination between dutyholders.
Completion and handover: make sure relevant health and safety information is brought together and, where required, the Health and Safety File is completed and handed over appropriately.
CDM compliance issues to avoid
Issues to avoid include:
- Appointing the Principal Designer too late to influence design and planning.
- Assuming CDM only applies to large projects.
- Treating CDM as a paperwork exercise rather than a process for managing risk.
- Failing to provide relevant information to other dutyholders.
- Poor coordination between designers, clients and contractors.
- Failing to keep health and safety information up to date as the project develops.
Frequently asked questions about CDM 2015
Does CDM 2015 apply to small projects?
Yes. CDM 2015 applies to construction work of all sizes. The duties and arrangements should be proportionate to the project and its risks.
Does CDM 2015 apply to domestic projects?
Yes. CDM applies to domestic construction work carried out on behalf of a domestic client, although the client’s duties are normally transferred to other dutyholders.
When is a Principal Designer required?
A Principal Designer must be appointed where a project involves, or is likely to involve, more than one contractor. For commercial clients, the appointment must be made in writing as soon as practicable and before the construction phase begins. On a domestic project, if no Principal Designer is appointed, the designer in control of the pre-construction phase takes on that role.
What is a Construction Phase Plan?
It is the plan for managing health and safety during the construction phase of a project. On a project involving only one contractor, that contractor must prepare the Construction Phase Plan.
Are the CDM Principal Designer and Building Regulations Principal Designer the same role?
No. In England, they have different functions and competence requirements, although the same organisation can carry out both roles where the relevant requirements are met. Where this happens, the client must confirm the dual appointment in writing.
How enevo can support CDM compliance
enevo provides CDM Principal Designer and advisory support for clients, designers and contractors. Support can include dutyholder advice, appointment and notification support, Pre-Construction Information management, design-phase risk coordination and Health and Safety File support.
Find out more about enevo’s CDM Principal Designer and Advisory Services.
