CDM duty checker
Answer a few questions about the client, your role and the size of the job. The checker tells you which CDM 2015 dutyholders must be appointed, what the domestic-client rule means for you, and whether the project must be notified to HSE on form F10.
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About the project
Answer these about the construction work you're planning. CDM 2015 applies to all of it — these questions work out which duties apply and whether HSE notification is needed.
Choose a client type and your role to see your duties.
CDM 2015 in plain terms
The Construction (Design and Management) Regulations 2015 (CDM 2015) set out who does what to keep construction work safe. They apply to all construction work — there is no minimum size, and they cover domestic jobs as well as commercial ones. This checker works out which dutyholder roles apply to your project and whether the work crosses the threshold for notifying the Health and Safety Executive (HSE).
The CDM 2015 dutyholders
| Dutyholder | What they do |
|---|---|
| Client | Makes suitable arrangements for managing the project, allows enough time and resources, provides pre-construction information and makes the right appointments in writing. |
| Principal designer | Plans, manages and monitors the pre-construction phase and coordinates health and safety in design. Required when there is more than one contractor. |
| Designer | Eliminates, reduces or controls foreseeable risks through design and shares the remaining risks. |
| Principal contractor | Plans, manages, monitors and coordinates the construction phase, and prepares and updates the construction phase plan. Required when there is more than one contractor. |
| Contractor | Plans, manages and monitors their own work. A sole contractor takes on the principal-contractor duties, including the construction phase plan. |
| Worker | Works safely, cooperates, reports anything that puts people at risk. |
When is a project notifiable (F10)?
Under regulation 6, a project is notifiable to HSE on form F10 if the construction work is scheduled to:
- last longer than 30 working days and have more than 20 workers working at the same time at any point in the project; or
- exceed 500 person-days of construction work.
Either condition on its own makes the project notifiable. Notification is an additional duty — it does not change the fact that CDM 2015 applies to every project. The F10 must be submitted before construction work starts. On a commercial project the client notifies; on a domestic project the duty passes to the contractor or principal contractor.
Domestic clients
A domestic client is someone having work done on their own home (or a relative's) that is not connected with a business. They have CDM duties, but in practice those duties pass automatically to the contractor (single contractor) or the principal contractor (more than one contractor). They can instead be carried out by the principal designer where there is a written agreement. The householder is not expected to manage the construction work.
A construction phase plan is needed on every project
This is the point most often missed on small jobs: a construction phase plan (CPP) is required for every construction project under CDM 2015 — including single-contractor and domestic work — and it must be in place before work starts. It should be proportionate to the risks: a short, focused plan for a small job, a fuller plan for a complex one. Suitable welfare facilities must also be provided from the outset.
This is guidance, not legal advice
Your exact duties depend on the specifics of the project, the contracts in place and how the work is organised. Use this checker to orient yourself, then confirm against HSE guidance and the Approved Code of Practice L153, “Managing health and safety in construction”. This tool does not certify that your arrangements meet your legal duties.
Source: HSE guidance on CDM 2015 (hse.gov.uk/construction/cdm/2015) and the Construction (Design and Management) Regulations 2015.
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