What are the CDM Regulations 2015?

The CDM Regulations 2015 are a series of rules designed to improve health and safety in the construction industry. They are extremely broad in scope, covering areas such as who is in charge of health and safety on any project, putting an appropriate team of people together, assessing risk, and communicating any issues effectively.

Why does this matter?

Complying with the regulations is about protecting your business as well as the people working on a site. If there was an accident on the site you were working on, failure to have carried out adequate risk assessments in compliance with the regulations would increase the chances of your being held liable.

Failing to comply with the regulations also breaches the terms of the Which? Trusted Traders Code of Conduct. It could also affect your public iability insurance and result in enforcement action being carried out by the Health and Safety Executive (HSE).

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Who do the regulations apply to?

Everyone,  is the short answer.

More precisely, the regulations apply to anyone carrying out any kind of construction project – this includes refurbishment and repairs, as well as installations. So that could be you if you’re involved in installing kitchens, bathrooms, roofing, building extensions, loft conversions or any other construction-related service.

The CDM Regulations 2015 cover projects large and small, from design stage through to the finishing touches. The regulations apply on commercial and domestic projects, whether you are contracted directly by the customer or subcontracted by another trader.

Traders most likely to be covered include:

  • builders
  • kitchen fitters
  • bathroom fitters
  • roofers
  • carpenters
  • plumbers
  • electricians
  • plasterers
  • bricklayers
  • painters and decorators.

What do I have to do to comply?

In general terms, you need to be responsible for preparing a risk-assessment plan (the construction-phase plan, or CPP), organising the work, and working with others to ensure health and safety procedures are in place.

The specific ‘duties’ that apply vary according to the size of the project and your role within it. If your business is the only one working on a project, then all responsibilities will fall to you. On large, commercial projects, the responsibilities will be split into different categories relating to the planning and carrying out of work, as explained below.

Designer/principal designer

This is the individual or business responsible for design work and planning in the pre-construction phase. The principal designer leads the planning stage if there is more than one on a project.

Designers could be architects, engineers, interior designers or any other trade that selects materials for a project and puts together or alters plans. An example of a principal designer would be a business that supplies kitchens or bathrooms, and contracts an installer to carry out the work.

A designer must:

  • take account of the principles of prevention in their design to minimise risks to contractors, workers and end users of any project
  • eliminate, reduce or control risks through their design
  • provide design information to others working on the project.

Principal contractor

The principal contractor is the individual or business that manages and co-ordinates the construction side of the project. If there’s a lead contractor on a project, by default they are the principal contractor.

An example of a principal contractor would be a kitchen installer contracted by a local authority, which in turn sub-contracts out specific electrical or gas work to qualified electricians and plumbers.

Principal contractors must:

  • liaise with the principal designer about any changes to the design or surveys
  • keep and update a health and safety file
  • draw up a Construction Phase Plan (CPP)
  • ensure any subcontractors are familiar with the CPP.

If you have smart phone you can download the Construction Industry Training Board’s CDM Wizard app to help plan and organise your construction job.  It’s available for iPhone and Android. Read our article for more tips on creating Construction Phase Plans for more details.

If the principal contractor is managing multiple subcontractors, they must:

  • draw up a site-induction form to ensure other workers know who is responsible for management and supervision, and highlight any risks on site.


A contractor on a large project will be responsible for managing health and safety in their area and reporting any risks to the principal contractor.

Where can I find more information?

Which? Trusted Traders has produced a free, downloadable guide for businesses, which takes you through the main points of the CDM regulations.

If you want a copy of the full regulations, the HSE provides a free, downloadable booklet.

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