CDM 2015, without the jargon
The Construction (Design and Management) Regulations apply to almost all building work, from a new estate to a kitchen refit. Here's who does what, and what it means for smaller jobs.
- construction work, homes included
- All
- construction work, homes included
- dutyholder roles
- 7
- dutyholder roles
- person days: notify HSE
- 500+
- person days: notify HSE
What CDM covers
CDM covers construction work of any size: building, alteration, conversion, fitting out, repair, maintenance, demolition, and installing services like plumbing, gas and electrics.
“A contractor must plan, manage and monitor construction work carried out either by the contractor or by workers under the contractor's control, to ensure that, so far as is reasonably practicable, it is carried out without risks to health or safety.”
In plain EnglishEven on a small job, you're expected to think it through before you start, keep an eye on it while it's happening, and be able to show you did.
Who does what
CDM puts duties on everyone involved, from the client who pays for the work to the workers on site.
The principal designer and principal contractor are only needed when more than one contractor works on the project.
Principal contractor
Regs 12–14- Plan, manage and monitor the construction phase
- Prepare the construction phase plan before work starts
- Organise cooperation between contractors and coordinate their work
- Make sure site inductions are given and keep unauthorised people out
- Provide welfare facilities throughout
- Give the principal designer information for the health and safety file
Domestic projects
Work on someone's own home, not done as part of a business, has a domestic client. CDM still applies in full.
One contractor
The client's duties pass to you, the contractor. You also draw up the construction phase plan.
More than one contractor
The client's duties pass to the principal contractor. A principal designer and principal contractor are needed.
Written agreement
The homeowner can agree in writing for the principal designer to take on the client duties instead.
Walk the site
Tap the numbers to see what an inspector would look for, and tap a regulation to see the duties behind it.
Scaffold
Inspect it before first use, after bad weather and at least every 7 days. No tag, no climb.
Notifying HSE
Larger projects must be notified to HSE on an F10 before construction starts. Check yours.
No F10 needed on these numbers. All the other CDM duties still apply, including a construction phase plan.
- –Over 30 working days and over 20 workers at once25 days, 8 at peak
- –Over 500 person days150 person days
The client normally notifies. For a domestic client it falls to the contractor or principal contractor.
The key documents
Three documents run through every CDM project. On a small job they can be short, but they need to exist.
Design
- Client appoints dutyholders
- Designers reduce risks on paper
Pre-construction
- Pre-construction information
- F10 to HSE if notifiable
Construction
- Construction phase plan before work starts
- Inductions and welfare
Handover
- Health and safety file to the client
- Kept for the building's life
Every project needs a construction phase plan. A health and safety file is needed when there's more than one contractor.
Small jobs checklist
For a typical small builder or trade, CDM on a domestic job usually comes down to this.
- Know whether you're the only contractor or one of several
- Agree who's in charge when subcontractors are on site
- Find out about the property first: asbestos, services, access
- Write a short construction phase plan before you start
- Provide toilets, washing, drinking water and somewhere to rest
- Keep the public, children and pets away from the work
- Give everyone a site induction, even on a small job
- Check your subcontractors are competent before they start
Quick check
Does CDM apply to a kitchen refit in someone's home?
How we help
As your competent person, this is part of your package or available as an add-on.
Construction phase plans
Short, proportionate plans for each job, or a template your team can fill in quickly and correctly.
Principal designer and contractor support
Advice and document support so you can carry out the PD or PC role with confidence.
Site inspections
Independent site visits that check what's really happening against your plan, with a clear report.
CDM advice on call
Straight answers on which CDM duties apply to your jobs, as part of your package.
Guidance reviewed October 2026. A plain-English summary of the law in England, Scotland and Wales, not legal advice. Always check the full text on legislation.gov.uk and the latest HSE guidance.
Not sure what CDM means for your jobs?
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