CDM 2015

CDM 2015 Duties Explained for Small Contractors

What CDM 2015 actually requires of a small UK contractor: duty holder roles, when to notify HSE, the construction phase plan, and the records you need.

Published 29 July 2026 8 min read SiteClick Team

The Construction (Design and Management) Regulations 2015 apply to every construction project in Great Britain, including a single-day domestic job. Most small contractors know the acronym and very little else. Here is what actually applies to you.

The duty holders

  • Client — anyone having construction work done. On a domestic job, the client duties usually transfer to the contractor (or the principal contractor if there is more than one).
  • Principal designer — required when more than one contractor is involved. Plans, manages and coordinates health and safety in the pre-construction phase.
  • Principal contractor — required when more than one contractor is involved. Plans, manages and coordinates the construction phase.
  • Contractor — anyone who carries out construction work. That is you.
  • Worker — anyone working on site.

The trigger everyone misses: if there is more than one contractor on the job, the client must appoint a principal designer and a principal contractor in writing. A builder plus an electrician is more than one contractor.

When you must notify the HSE

Notify (form F10) if the work will last longer than 30 working days and have more than 20 workers simultaneously at any point, or if it will exceed 500 person-days. Most small jobs are not notifiable — but the rest of CDM still applies.

The construction phase plan

Every project needs one, however small. It does not need to be long. It needs to cover:

  • A description of the project and key dates
  • Management arrangements: who is responsible for what
  • Site rules and induction arrangements
  • The significant risks and how they are controlled
  • Welfare arrangements — toilets, washing, drinking water, rest area
  • Emergency procedures

Two or three pages is normal for a domestic extension. The failure is not having one at all.

Welfare is not optional

Schedule 2 requires suitable toilets, washing facilities, drinking water, changing and rest facilities from day one. "The client said we could use their bathroom" needs to be written down and actually agreed.

The records that prove you complied

If something goes wrong, the question is what you can evidence. Keep:

  • The construction phase plan and any revisions
  • RAMS for each significant activity, signed by the operatives
  • Site inductions with signatures and dates
  • Toolbox talk attendance records
  • Competence records: CSCS, CPCS, IPAF, PASMA and their expiry dates
  • Equipment and scaffold inspection records
  • A daily site diary noting conditions, personnel and incidents
  • Accident book entries and RIDDOR reports

The practical failure mode

Nobody gets prosecuted for having imperfect paperwork on an uneventful job. The problem appears after an incident, when an inspector asks for the briefing record and it does not exist — because it was on a sheet in a van that is long gone.

Keeping the induction signatures, the toolbox talks, the card expiry dates and the daily diary in one app means the evidence exists by default. SiteClick was built around exactly that record set for UK sites.

CDM 2015Health & SafetyCompliance

Frequently asked questions

Does CDM 2015 apply to domestic jobs?

Yes. CDM applies to all construction work including domestic projects. The client duties normally pass to the contractor, or to the principal contractor where more than one contractor is involved.

Do I need a construction phase plan for a small job?

Yes. Every construction project requires a construction phase plan, however small. For a small domestic job it can be two or three pages.

When do I need to notify HSE with an F10?

When work will last more than 30 working days with more than 20 workers at once, or exceed 500 person-days.

Keep reading

One app for the records this guide describes

Photos, diaries, RAMS, timesheets and invoicing. From £13 a month.