When is an F10 required? A plain guide for builders

When is an F10 required? A plain guide for builders

When is an F10 required? An F10 is required when construction work is expected to last longer than 30 working days and have more than 20 workers on site at the same time at any point, or when the work will exceed 500 person days. It is the HSE notification for a notifiable construction project under CDM 2015.

That sounds simple, but small builders usually get stuck on the details. A domestic extension can be notifiable. A commercial refit can be notifiable. A short job with a busy programme may still stay below the line. The useful test is not whether the job feels big. It is whether the programme and labour count cross the notification threshold.

What is an F10?

The F10 is the online form used to notify the Health and Safety Executive of a notifiable construction project. HSE's own F10 page says you need contact details for the client, principal designer and principal contractor before you complete it. Once the notification is submitted, HSE sends a unique serial number so the notification can be accessed or edited later.

For a small site, treat the F10 as part of the job file. Save the serial number. Download the PDF from the confirmation screen. Keep it with the construction phase plan, RAMS and other CDM paperwork. The notification is not a safety plan by itself, but it proves the project has been notified.

When is an F10 required under CDM 2015?

A project is notifiable if the construction work is expected to meet either of these tests:

• it will last longer than 30 working days and have more than 20 workers working at the same time at any point; or
• it will exceed 500 person days.

Those two tests work differently. The first needs both parts: more than 30 working days and more than 20 people on site at the same time at some point. A long job with a tiny team may not pass that test. A short job with a big team may not pass it either. The second test is total labour over the project: one person working one day is one person day, so ten people for fifty-one days is 510 person days.

HSE's CDM FAQ also says every day on which construction work is likely to be carried out should be counted, even if the work on that day is short. That includes holidays and weekends if construction work is expected to happen then.

Quick examples for small jobs

A two-week bathroom refit with two people is unlikely to need an F10. It is short, the labour total is small and there will not be more than 20 workers on site at once.

A domestic extension running 12 weeks with four or five trades rotating through might not hit more than 20 workers at one time, but it can still creep towards the 500 person day test. Count it properly rather than guessing.

A larger house renovation with several subbies, a busy programme and overlapping trades is the kind of job where the F10 question should be answered before work starts. If your programme shows a long duration and a lot of labour days, do the calculation early.

Who has to send the F10?

For a commercial client, the client must notify HSE. In practice, they may ask the builder, principal designer or principal contractor to help, but the duty sits with the commercial client.

For a domestic client, the homeowner normally does not carry out the notification. HSE says notification must be carried out by the contractor, or the principal contractor if there is more than one contractor. A principal designer can do it where there is a written agreement that they will carry out the client's duties.

That matters for small builders. If you are running a notifiable domestic job, do not assume the homeowner will know what an F10 is. Sort the duty before the job starts and keep the evidence with the rest of the paperwork.

What details do you need before you start the form?

Have these ready before opening the online F10 form:

• the client details;
• the principal designer details;
• the principal contractor details;
• the site address and project description;
• the planned start date and expected duration;
• enough programme information to support why the project is notifiable.

Where there is only one contractor on a notifiable project, HSE says the client does not need to appoint a principal designer or principal contractor. When completing the form, input the sole contractor as the principal designer and principal contractor, then explain in the free text box that it is a single-contractor project.

What goes alongside the F10?

The F10 is only the notification. You still need suitable arrangements for the job. On a notifiable project, that usually means a construction phase plan, clear RAMS for higher-risk tasks, induction information, emergency arrangements and welfare details.

If you are starting from scratch, the free RAMS generator can help you set out task controls in plain English. For the wider job plan, the construction phase plan workflow keeps the site details, roles and arrangements in one place. If you are producing this sort of paperwork regularly, check the plans and pricing before you lose another evening to Word templates.

Common F10 mistakes to avoid

Do not treat the F10 threshold as a rough feel for whether the job is big. Count the expected working days, worker overlap and person days.

Do not leave notification until the scaffold is up and trades are already on site. HSE says notice should be given as soon as practicable before the construction phase begins.

Do not lose the serial number or PDF. You may need them if the notification has to be retrieved or edited.

Do not treat the F10 as the whole CDM job. It tells HSE the work is happening. It does not replace the CPP, RAMS, induction or your duty to manage the work safely.

The plain rule is this: if the job is expected to pass the 30 working day and 20-worker test, or exceed 500 person days, get the F10 sorted before work starts and file it with the rest of the site paperwork.