CDM are the main set of regulations for managing the health, safety and welfare of construction projects. Watch our short video which explains the basics.

Key points

The project must follow all of Steps 1 and 2 PLUS the client must notify the Health and Safety Executive (HSE) of the project.

Step 1

All projects must have:

• workers with the right skills, knowledge, training and experience,

• contractors providing appropriate supervision, instruction and information,

• a written construction phase plan. Download this example.

Step 2

Projects involving more than one contractor (domestic or non-domestic):

must follow Step 1 plus:

• must appoint a principal designer and principal contractor

• must have a health and safety file.

Step 3

If work is scheduled to:

• last longer than 30 working days and,

  • will have over 20 workers working simultaneously at any point in the project, OR exceeds 500 person days

The project must follow all of Steps 1 and 2 PLUS the client must notify the Health and Safety Executive (HSE) of the project.

You may also be interested in

The HSE is a good source of information and guidance. It has produced:

• The key publication Managing health and safety in construction - Construction (Design and Management) Regulations 2015 - (L153) on the legal requirements for CDM.

• Some very useful frequently asked questions pages. These are not formal HSE guidance and are not intended to cover every aspect of the topic or be a ‘one size fits all’ answer, but provide consistent and helpful answers to some of the most common questions that have arisen about CDM. 

• HSE Construction webpages and dedicated Resources page.