Online, Virtual and Classroom Courses
Fully Certified NEBOSH, IOSH, ISEP Accredited
7-Day Customer Service
David Bryan BSc, CMIOSH, CMAPS

CDM Roles and Responsibilities - CDM 2015 Duty Holders

January 2015

This blog was updated in August 2023

In light of the Construction (Design & Management) Regulations (CDM) 2015 having been published to replace CDM 2007 enforced 6 April 2015, here is an outline of all duty holders involved in a construction project and their duties.

Clients

Clients are organisations or individuals for whom a construction project is carried out. Make suitable arrangements for managing a project. This includes making sure:

  • Domestic Clients Other duty holders are appointed
  • Sufficient time and resources are allocated
  • Relevant information is prepared and provided to other duty holders
  • The principal designer and principal contractor carry out their duties
  • Welfare facilities are provided

Domestic clients are people who have construction work carried out on their own home, or the home of a family member that is not done as part of a business, whether for profit or not.

Domestic clients are in the scope of CDM 2015, but their duties as a client are normally transferred to the contractor on a single contractor project, or the principal contractor, on a project involving more than one contractor. However, the domestic client can choose to have a written agreement with the principal designer to carry out the client duties.

Designers

Designers­ are those, who as part of a business, prepare or modify designs for a building, product or system relating to construction work.

  • When preparing or modifying designs, to eliminate, reduce or control foreseeable risks that may arise during construction, and the maintenance and use of a building once it is built.
  • Provide information to other members of the project team to help them fulfil their duties.

Principal Designers

Principal designers­ are designers appointed by the client in projects involving more than one contractor. They can be an organisation or an individual with sufficient knowledge, experience and ability to carry out the role.

They must plan, manage, monitor and coordinate health and safety in the pre-construction phase of a project. This includes:

  • Identifying, eliminating or controlling foreseeable risks
  • Ensuring designers carry out their duties
  • Prepare and provide relevant information to other duty holders
  • Liaise with the principal contractor to help in the planning, management, monitoring and coordination of the construction phase.

Principal Contractors

Principal contractors  are contractors appointed by the client to coordinate the construction phase of a project where it involves more than one contractor. They must plan, manage, monitor and coordinate the construction phase of a project. This includes:

  • Contractors Liaising with the client and principal designer
  • Preparing the construction phase plan
  • Organising cooperation between contractors and coordinating their work, ensuring
    • Suitable site inductions are provided
    • Reasonable steps are taken to prevent unauthorised access
    • Workers are consulted and engaged in securing their health and safety
    • Welfare facilities are provided

Contractors are those who do the actual construction work and can be either an individual or a company. Their duties include:

  • Plan, manage and monitor construction work under their control so that it is carried out without risks to health and safety
  • For projects involving more than one contractor, coordinate their activities with others in the project team, in particular, comply with directions given to them by the principal designer or principal contractor
  • For single-contractor projects, prepare a construction phase plan

Workers

Workers­ are the people who work for or under the control of contractors on a construction site. Workers must:

  • Be consulted about matters which affect their health, safety and welfare
  • Take care of their own health and safety and others who may be affected by their actions
  • Report anything they see which is likely to endanger either their own or others’ health and safety
  • Co-operate with their employer, fellow workers, contractors and other duty holders.

Our range of CDM courses provide in-depth explanations into the Construction (Design and Management) Regulations 2015. Click the buttons below to view our different CDM courses.

Related Blogs

  • HSE Launches Campaign Urging Employers to Assess and Control Workplace Noise and Vibration Risks Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    HSE Launches Campaign Urging Employers to Assess and Control Workplace Noise and Vibration Risks

    HSE's new campaign urges employers to assess, control and protect against noise and vibration. Brenig Moore explains the duties and practical next steps.
    27.10.26
  • European Parliament Backs Tougher Limits on Cancer-Causing Chemicals at Work Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    European Parliament Backs Tougher Limits on Cancer-Causing Chemicals at Work

    Discover what the EU's sixth CMRD revision means for exposure limits, firefighters, PPE and training, and why UK safety pros should act now.
    19.10.26
  • More Than 6 Million Vapes Binned Each Week as Battery Fires Hit Waste Sites Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    More Than 6 Million Vapes Binned Each Week as Battery Fires Hit Waste Sites

    Find out why binned vapes are causing battery fires in bin lorries and waste sites, and what health and safety teams can do to cut the risk.
    12.10.26
  • Most E-Bike and E-Scooter Fires Reported in 2025 Started Indoors or at Home Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    Most E-Bike and E-Scooter Fires Reported in 2025 Started Indoors or at Home

    OPSS received reports of 267 e-bike and e-scooter fires in 2025, and 55% started indoors. Brenig Moore explains what it means for your fire risk assessment.
    06.10.26
  • Nearly Half of UK Employers Step Up In-House Talent Development, CIPD Report Finds Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    Nearly Half of UK Employers Step Up In-House Talent Development, CIPD Report Finds

    Nearly half of UK employers are growing talent in-house, says the CIPD. Brenig Moore explains what it means for safety training and competence.
    29.09.26
  • TfL to Retrofit Bus Cabs With Air Conditioning by 2027 Following Driver Heat Complaints Image
    Brenig Moore DipNEBOSH, CMIOSH, CEnvH

    TfL to Retrofit Bus Cabs With Air Conditioning by 2027 Following Driver Heat Complaints

    Discover what TfL’s pledge to air condition bus cabs by 2027 means for heat risk, duty of care and the UK’s missing legal temperature limit.
    22.09.26
Section Curve
Case Studies

Real Life Stories

Find out how learners look back on their training with Astutis. Our case studies give our learners, both individual and corporate, a platform to share their Astutis experience. Discover how training with Astutis has helped past learners and delegates make the world a safer place, one course at a time.
More Image
Bottom Curve
What People Say

Hear What Our Learners Have To Say

We're always there for our customers. 98% of our learners rated their overall experience as good or outstanding. We will always pride ourselves on our customer service. But don’t take our word for it, here is what our customers have to say
  • "Fantastic tutor and cooperative staff: really a “Gold” learning partner."

    22.10.2026
  • "Very practical course, but very difficult to find a relevant job. However, everyone should take this course."

    22.10.2026
  • "I had a great learning experience with Astutis while completing the ISEP Certificate in Sustainability and Environmental Management. The course was well structured, and the learning materials helped me develop my knowledge and understanding of environmental management. I would like to thank the Astutis team for their guidance and support throughout my learning journey. I am proud to have achieved a Distinction and would recommend Astutis to anyone looking to develop their professional knowledge and qualifications in sustainability and environmental management."

    Mutwali Elamin Ahmed
    19.10.2026
  • "The course was well structured and provided useful knowledge in sustainability and environmental management. The study materials were clear and supported my learning throughout the course. I appreciate the guidance and support from the Astutis team. I am proud to have achieved a Distinction in the ISEP Certificate in Sustainability and Environmental Management. I would recommend this course to anyone looking to develop their knowledge and career in environmental management and sustainability."

    Mutwali Elamin Ahmed
    19.10.2026
  • "Astutis always provide excellent customer service. There is a fantastic range of courses that align with our business needs perfectly. Great communication from everyone I have dealt with and I would like to give a particular shout out to Michelle who could not be any more helpful if she tried. She is always on hand to help with any queries with a quick response time and reassuring always. Thank you Astutis :)"

    Ashleigh Sparkes
    07.10.2026
  • "Brilliant courses - always receive great feedback from colleagues!"

    Ashleigh Sparkes
    07.10.2026
  • "Great training provider with amazing co-ordinators"

    Caitlin
    07.10.2026
  • "Great offering of courses which suits the requirements of our organisation"

    Caitlin
    07.10.2026
  • "Astutis provided a high-quality learning experience that helped me build confidence in my studies. Their flexibility and professional support made it easier to progress while working full-time offshore. I would highly recommend Astutis to anyone looking to further their professional qualifications"

    Jose Malila
    06.10.2026
  • "The course was well structured, engaging, and easy to follow. The learning materials were comprehensive and relevant to real workplace situations, making it easier to apply the knowledge in practice. I particularly appreciated the flexibility of studying at my own pace while balancing work commitments. Overall, the course has helped me improve my professional knowledge and confidence, and I would highly recommend it to others."

    Jose Malila
    06.10.2026