CDM 2015 Notifiable Project: Thresholds and the F10 Explained

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

A notifiable project is one that is big enough or long enough that the client has to tell the HSE about it before work starts. Under CDM 2015 that is decided by two simple thresholds, and if the job crosses either one the client submits a form called the F10. Notification does not change who does what on site, it is one extra step for the client. Here is what makes a project notifiable, where the thresholds sit, and how the F10 works in plain English.

What notifiable actually means

Notifiable means the client must formally notify the Health and Safety Executive that construction work is going to take place, before the construction phase begins. It is a heads up to the regulator, nothing more. It does not create new duty holders, it does not change the roles, and it does not on its own make a job more dangerous or more heavily regulated. Plenty of construction work is not notifiable and still has to follow the rest of CDM 2015 in full. Notification is simply the paperwork trigger that sits on top for larger jobs.

The two thresholds

A project is notifiable if the construction work is scheduled to either run long with a sizeable crew, or add up to a lot of labour overall. In practice you check two figures:

• Duration and crew: the work is scheduled to last longer than 30 working days and have more than 20 workers working at the same time at any point during the project.
• Person days: the work is scheduled to exceed 500 person days of construction work, which is workers multiplied by days.

If either threshold is met, the project is notifiable. The first test needs both the length and the headcount together, so a long job with a tiny crew or a short job with a big crew may not trip it, but the 500 person day test can still catch a job that the first test misses.

Worked examples

The thresholds are easier to judge against real jobs. A refurbishment scheduled for 40 working days with 25 people on site at peak is notifiable, because it clears more than 30 days and more than 20 workers at once. A two week fit out with 6 workers is not notifiable on the first test and comes nowhere near 500 person days, so it is not notifiable. A groundworks package running 60 days with an average of 9 workers hits roughly 540 person days, so it is notifiable under the second test even though it never has 20 people on at once. When in doubt, work out the person days and check both tests.

The F10 notification

Notification is made on a form called the F10, submitted to the HSE. It captures the basics of the project: the site address, a brief description of the work, the planned dates, and who the duty holders are, including the client, the principal designer and the principal contractor. The client submits it before the construction phase starts, and if key details change significantly during the job the notification should be updated. The F10 is submitted online through the HSE, and a copy of the notification information is usually displayed where workers can see it on site.

Who is responsible for notifying

The duty to notify sits with the client. It is one of the client duties under CDM 2015 and it cannot be quietly handed to the contractor as a favour. On a domestic project the notification duty, like other client duties, generally passes to the principal contractor or the contractor, so a domestic client is not usually the one filing the F10. On commercial work the client is squarely responsible and needs to make sure it is done before boots hit the ground.

What notification does not change

It is worth being clear about the limits. Being notifiable does not add a principal designer or principal contractor that was not already required, those roles are triggered by having more than one contractor, not by notification. It does not change the construction phase plan requirement, which applies to every project regardless of size. And it does not mean the HSE will inspect or approve the job, the F10 is a notification, not a permission. The rest of CDM applies exactly the same whether or not the F10 is required.

Frequently asked questions

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.