Compliance Guide

CDM 2015 Flowchart: Does It Apply and Who Does What?

A practical guide for UK site managers, contractors and small builders.

CDM 2015 applies to every construction project in Great Britain, from a loft conversion to a tower crane, so the real questions are not whether it applies but how much of it applies and who carries which duty. Work through it as a simple flow: is it construction work, how many contractors are involved, and is the project notifiable. Answer those three and the duty holders and paperwork fall into place. Here is the CDM 2015 flow set out step by step in plain English.

Step 1: Is it construction work?

If the work is building, altering, maintaining, repairing or demolishing a structure, it is construction work and CDM 2015 applies. That covers domestic extensions, commercial fit outs, groundworks, roofing and civil engineering alike. There is no minimum size or value below which CDM switches off. The regulations always apply to construction work, so the useful next question is not "does CDM apply" but "which parts apply to this job".

Step 2: How many contractors are involved?

This is the fork that decides most of the roles. If only one contractor is doing the work, it is a single contractor project. If two or more contractors are involved, and that threshold is easy to cross with, say, a builder plus an electrician, then more than one contractor is involved and the fuller set of duty holders is triggered.

One contractor: the client and the contractor carry the duties. The contractor plans, manages and monitors the work and provides the relevant parts of the construction phase plan.
More than one contractor: the client must appoint a principal designer and a principal contractor in writing, and both a construction phase plan and a health and safety file are required.

Step 3: Is the project notifiable?

A project is notifiable to the HSE if the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or if it exceeds 500 person days of work. If either threshold is met, the client must notify the HSE by submitting an F10 before the construction phase begins. Notification does not change who the duty holders are or add extra roles, it is simply a form the client sends. Many domestic and short projects are not notifiable but still need the rest of CDM.

Who the duty holders are

Once you know how many contractors are involved, the CDM 2015 duty holders map out cleanly:

Client: makes suitable arrangements for managing the project, provides pre construction information, and makes the written appointments. On a notifiable job the client submits the F10.
Principal designer: plans, manages and coordinates health and safety during the pre construction phase, on projects with more than one contractor.
Principal contractor: plans, manages and coordinates health and safety during the construction phase, on projects with more than one contractor.
Designers: eliminate, reduce or control foreseeable risks through their design decisions.
Contractors: plan, manage and monitor their own work and coordinate with others on site.
Workers: follow the site rules, report anything unsafe and look after their own and others' safety.

Which documents are required

The paperwork follows the same branches. A construction phase plan is required on every project, single contractor jobs included, and must be in place before work starts. A health and safety file is required only where more than one contractor is involved, and it is handed over to the client at the end for future work on the structure. On a notifiable job add the F10 notification. Nothing here is about filing for the sake of it, each document is the practical record of how the significant risks are being controlled.

The flow in one line: construction work means CDM applies; more than one contractor means a principal designer, a principal contractor and a health and safety file; over 30 days with 20 plus workers at once, or over 500 person days, means notify the HSE with an F10.

Frequently asked questions

Does CDM 2015 apply to small or domestic jobs?

Yes. CDM 2015 applies to all construction work with no lower size limit. On domestic projects some client duties usually pass to the contractor or principal contractor, but the core duties and the construction phase plan still apply.

When is a project notifiable under CDM 2015?

When the work lasts longer than 30 working days with more than 20 workers on site at the same time at any point, or exceeds 500 person days. The client then submits an F10 to the HSE before the construction phase starts.

When do you need a principal contractor and principal designer?

Whenever more than one contractor is involved. The client must appoint both in writing, and a health and safety file becomes required in addition to the construction phase plan.

The shortcut

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This article is general guidance for UK construction and is not legal advice. For requirements specific to your work, check current HSE guidance and your own duty holder obligations under CDM 2015.