Understanding the CDM Regulations in Construction
The Construction (Design and Management) Regulations 2015, known as CDM 2015, set out the legal requirements for managing health and safety on construction projects in the UK. These regulations apply to all construction work, regardless of size, duration or complexity, and place clear responsibilities on clients, designers, principal designers, principal contractors, contractors and workers.
This guide explains what CDM 2015 covers, why the regulations exist and what each duty holder must do to keep people safe and legally compliant.
What are the CDM Regulations?
CDM 2015 was introduced to improve health and safety across the construction sector. The regulations aim to reduce accidents, improve planning and coordination and ensure that everyone involved in a project understands their responsibilities.
CDM applies to all forms of construction work, including new builds, refurbishments, extensions, demolition, repairs, maintenance and any work that changes a structure.
Why CDM Matters
Construction is one of the highest risk industries in the UK. Many incidents happen because of poor planning, unclear responsibilities or ineffective communication between project teams. CDM addresses these issues by focusing on three core principles:
Managing risk from the earliest design stages.
Ensuring clear communication between everyone involved.
Making sure duty holders work together to keep people safe.
Following CDM improves project safety, reduces delays and ensures compliance with legal requirements.
Duty Holders Under CDM 2015
CDM identifies several specific roles. Each has legal responsibilities throughout the project.
Clients
Commercial clients must make suitable arrangements for planning, managing and monitoring the project. Their responsibilities include:
Appointing a competent Principal Designer and Principal Contractor on projects with more than one contractor.
Providing key project information.
Allocating enough time and resources.
Ensuring construction work does not begin until proper arrangements are in place.
Designers
Designers include architects, engineers and anyone who influences design decisions. Their duties include:
Eliminating foreseeable risks where possible.
Reducing and controlling risks that cannot be eliminated.
Providing relevant design and risk information to other duty holders.
Principal Designers
A Principal Designer must be appointed by the client for any project that involves more than one contractor. They are responsible for:
Planning, managing and monitoring the pre-construction phase.
Coordinating all designers to ensure health and safety risks are addressed.
Identifying and eliminating foreseeable risks.
Providing information to the Principal Contractor and client.
Principal Contractors
The Principal Contractor manages health and safety during the construction phase. Their responsibilities include:
Planning, managing and monitoring construction work.
Preparing the Construction Phase Plan.
Providing inductions, welfare arrangements and safe systems of work.
Coordinating contractors and keeping communication clear.
Ensuring workers are competent and properly trained.
Contractors
Contractors must plan, manage and monitor the work under their control. They must:
Ensure workers have the right skills, training and experience.
Cooperate with the Principal Contractor and other contractors.
Follow the Construction Phase Plan and site rules.
Workers
Workers have responsibilities too. They must:
Take reasonable care of their own health and safety.
Follow training, instructions and site rules.
Report hazards or unsafe practices.
Cooperate with their employer and other duty holders.
Notifiable Projects (F10)
Some projects must be notified to the Health and Safety Executive (HSE). A project becomes notifiable if the construction work is expected to:
Last longer than 30 working days and have more than 20 workers on site at the same time, or
Exceed 500 person-days of construction work.
For commercial projects, the client is legally responsible for ensuring an F10 notification is submitted before work begins. The client may ask another duty holder, such as the Principal Designer or Principal Contractor, to submit it on their behalf.
Key CDM Documentation
CDM requires specific documentation to help duty holders plan and manage work safely.
Pre-Construction Information
Information provided by the client to help designers, contractors and the Principal Designer plan the project and understand risks.
Construction Phase Plan
A document that outlines how the construction phase will be managed. It is prepared by the Principal Contractor on projects with more than one contractor, or by the sole contractor on single-contractor projects.
Health and Safety File
A record of essential information needed for future use, maintenance, alterations or demolition. The Principal Designer coordinates the development of the file and hands it to the client at project completion.
How CDM Improves Safety
CDM 2015 creates a structured approach to health and safety by:
Reducing risk through better design and planning.
Improving communication and coordination between duty holders.
Establishing clear lines of responsibility.
Helping manage high-risk activities such as working at height, lifting operations, excavations and temporary works.
Promoting safer and more efficient project delivery.
NVQs That Support CDM Duty Holder Roles
Professionals who act as Principal Designers, Principal Contractors, Site Managers or Supervisors often need qualifications that demonstrate their competence and understanding of construction management, health and safety and CDM responsibilities.
The NVQs below could be suitable depending on the role:
For Principal Designers:
For Principal Contractors or Site Managers:
For Supervisors supporting CDM duties:
