What is CDM?

What is CDM?

What is CDM?

If you have anything to do with construction, you'll have come across CDM. It stands for the Construction (Design and Management) Regulations 2015, as formulated by the Health and Safety Executive (HSE).

CDM is an all-embracing set of regulations that apply to all aspects of construction work, from its inception to completion and beyond. Its intention is to provide the best possible health and safety protection, not only during the project but also for any additional future works. Some terms also apply to the building's use and maintenance after completion, together with general rules covering all construction sites.

Who needs to know about it?

The CDM regulations cover all projects, whether large or small, brief or protracted, domestic or commercial. Duties of care are imposed on all members of the project, especially on key personnel like clients, designers and contractors. The HSE subdivides these into several categories, with specific duties for each category.

Working together

All members of a project team must work closely together. Even if it's just a domestic repair, you'll still need to consult with a builder and materials supplier. Larger projects may involve a whole list of contributing designers, contractors and clients. The network of responsible persons, or duty holders, must collaborate to ensure that all necessary health and safety precautions are applied.

Under the CDM regulations, you'll also have to produce certain documentation that covers the main stages of the construction. These documents are required by law at each stage of a project.

Before you start any construction work, you must collect all available project information on the site, plus any existing plans and surveys. This includes your client brief, project arrangements and a health and safety risk assessment. This is the pre-construction information that gets forwarded to your designers and contractors.

It's the duty of the principal contractor to develop a construction phase plan where there are two or more contractors working on a project, before any work can commence. This sets out exactly how construction risks will be controlled. The plan addresses existing site hazards and sets arrangements in place for health and safety management throughout the project's duration. The plan must be reviewed and updated regularly to take account of any additional activities or participants in the project.

When construction work is complete, a health and safety file must be delivered to the client. This is the duty of the principal designer, who is responsible for collecting the relevant information from the parties concerned.


In certain circumstances, CDM regulations require that projects be notified to the HSE. These circumstances include your project requiring more than 500 person-days of work, or more than 20 people working for over 30 days. In these cases, a form F10 has to be completed (usually by the client or principal contractor) and submitted to the HSE.

How can WSS help?

At WSS we offer a full range of CDM support services. These cover every aspect of the regulations and duties of care you might be expected to encounter. We can help you interpret the regulations in the light of your particular project, and ensure that you have all the necessary protections in place.