CDM 2015 dutyholder identifier

Work out which CDM role you hold, who must be appointed, whether the project is F10 notifiable, and which documents should exist before site work starts.

Before you use the selector

CDM 2015 means the Construction (Design and Management) Regulations 2015. A dutyholder is a person or organisation with legal duties under those regulations, such as a client, designer, contractor, principal designer, or principal contractor.

This page follows the HSE dutyholder structure. It is a planning aid for UK construction projects, not a substitute for reading the regulations, HSE L153, or taking project-specific legal advice.

Principal designer, the designer appointed to plan, manage, monitor, and coordinate pre-construction health and safety.

Principal contractor, the contractor appointed to plan, manage, monitor, and coordinate the construction phase.

F10

F10 notification, the online notice submitted to HSE when a construction project meets the notification thresholds.

Identify your CDM position

Select the project setup. Matching dutyholder cards and F10 trigger rows are highlighted below.

Client type

A domestic client has construction work carried out on their own home and not for a business.

Your role on the project

How many contractors will be involved?

Count subcontractors as contractors. If more than one contractor is involved, CDM principal roles apply.

Planned construction duration

working days

Peak number of workers at any one time

Estimated total worker-days

Person-days means all workers added together across the project. Ten workers for 50 days equals 500 person-days.

Your likely position

Commercial client with principal appointments

You should appoint a principal designer and principal contractor because more than one contractor is involved.

Immediate checks

F10 notification trigger

A project is notifiable to HSE if it is expected to last longer than 30 working days and have more than 20 workers working at the same time at any point, or if it is expected to exceed 500 person-days. These thresholds come from CDM Regulation 6 and the HSE CDM FAQ.

Trigger	How to read it	Your selector result
Longer than 30 working days and more than 20 workers at peak	Both parts must be true. Thirty days exactly is not enough unless the person-day trigger also applies.	Checking...
More than 500 person-days	Add each worker's working days across the whole construction phase.	Checking...

CDM dutyholder cards

The selector highlights the roles most likely to apply to your setup. On real projects, one organisation can hold more than one duty, but each duty still needs to be covered.

Commercial client

A business or organisation having construction work carried out.

• Make suitable arrangements for managing the project.
• Allow enough time and resources for health and safety.
• Provide pre-construction information, meaning existing site and design risk information needed before work starts.
• Appoint the PD and PC in writing where more than one contractor is involved.
• Ensure a construction phase plan and welfare arrangements are in place.

Domestic client

A person having work done on their own home, not for a business.

• Domestic client duties normally transfer to the contractor, or to the PC where there is more than one contractor.
• The domestic client can agree in writing that the PD carries the client duties instead.
• The contractor or PC still needs a construction phase plan for the work.

Designer

Anyone preparing or modifying designs, including drawings, specifications, and design details.

• Eliminate, reduce, or control foreseeable design risks.
• Provide information about significant remaining risks.
• Cooperate with the PD and other designers.
• Do not start design work unless satisfied that the client understands their CDM duties.

Principal designer

Required when more than one contractor is involved.

• Plan, manage, monitor, and coordinate health and safety in the pre-construction phase.
• Help the client gather pre-construction information.
• Coordinate designers and pass relevant information to the PC.
• Prepare the health and safety file, meaning the record of information needed for future maintenance, cleaning, alteration, or demolition.

Principal contractor

Required when more than one contractor is involved.

• Plan, manage, monitor, and coordinate the construction phase.
• Prepare and keep the construction phase plan, meaning the live plan for site risks, rules, welfare, and management arrangements.
• Organise site induction, cooperation, consultation, and worker engagement.
• Make sure welfare facilities are provided from the start and remain suitable.

Contractor

Anyone carrying out, managing, or controlling construction work.

• Plan, manage, and monitor the work under their control.
• Check workers have the right skills, knowledge, training, and experience.
• Cooperate with the PC and follow the construction phase plan.
• If there is only one contractor, prepare the construction phase plan.

Worker and supervisor

People carrying out construction work, including site supervisors when they also control work activities.

• Take reasonable care of their own health and safety and that of others affected by their acts.
• Cooperate with employers, contractors, and the PC.
• Report anything likely to endanger health or safety.

Supervisors also need to make sure instructions, permits, exclusion zones, and RAMS controls are followed on site. RAMS means risk assessments and method statements.

Single contractor or multiple contractors?

This is the switch that most often changes the CDM structure. A small job can still need principal roles if more than one contractor is involved.

One contractor only

• No PD or PC appointment is required.
• The contractor must prepare the construction phase plan.
• The client still needs suitable arrangements and pre-construction information.
• F10 notification can still apply if the duration or person-day thresholds are exceeded.

More than one contractor

• A PD and PC must be appointed.
• The PC prepares the construction phase plan.
• The PD coordinates pre-construction health and safety and prepares the health and safety file.
• Domestic client duties transfer to the contractor, PC, or PD by written agreement.

Document checklist

0 / 8 checked

Use this as a pre-start prompt. It does not prove compliance by itself, but it helps expose missing appointments or missing information before work starts.

Client brief and CDM dutyholder appointments recorded

For multiple-contractor projects, the PD and PC appointments should be clear and in writing.

Pre-construction information issued

Existing surveys, asbestos information, service records, site constraints, design hazards, and public interface risks.

Construction phase plan prepared before site setup

Required for all construction projects. It should match the actual work, not a generic template.

Welfare arrangements confirmed

Toilets, washing, drinking water, rest facilities, drying area, first aid, and emergency procedures should be ready from day one.

Designer risk information issued to the PC

Significant residual risks should be clear enough for pricing, sequencing, temporary works, and site controls.

Skills, knowledge, training, and experience checks recorded

Use role-specific evidence, such as training records, cards, supervision arrangements, and previous experience.

F10 notification checked and displayed if needed

Notifiable projects need the notice submitted as soon as practicable before construction begins, and the notice should be clearly displayed on site.

Health and safety file owner agreed

The file should collect information needed for future maintenance, cleaning, alteration, and demolition.

Tick each item as you confirm it.

Frequently asked questions

Does a small construction job need a construction phase plan?

Can the same company be principal designer and principal contractor?

Who submits the F10 notification?

Does CDM only apply to notifiable projects?

Sources

HSE CDM 2015 dutyholder responsibilities - client, designer, contractor, principal designer, and principal contractor duties
HSE summary of CDM 2015 - overview of what changed and how the regulations apply
HSE commercial client guidance - client duties for business and organisational projects
HSE domestic client guidance - how domestic client duties transfer
HSE CDM FAQ - notification threshold wording and common CDM questions
HSE F10 notification guidance - how to notify HSE before construction starts
HSE F10 online notification form - project notification service
HSE L153 managing health and safety in construction - legal guidance on CDM 2015
HSE CIS80 construction phase plan - template plan for small projects
The Construction (Design and Management) Regulations 2015 - legislation text

Related resources

Site safety induction checklist Temporary works compliance checklist PPE compliance quick reference Industrial and commercial construction