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22nd July, 2016

How To Calculate If Your Construction Project Is CDM Notifiable

Under CDM 2015 the rules regarding notification requirements have changed, and the changes may be subtle but they can have a big impact on your project. How do we calculate if your construction project is CDM notifiable?

First, let's look at what the regulations say...


6.—(1) A project is notifiable if the construction work on a construction site is scheduled to—

(a)last longer than 30 working days and have more than 20 workers working simultaneously at any point in the project; or

(b)exceed 500 person days.

The Construction (Design and Management) Regulations 2015

Ok, so how do we calculate this?

Well, you can cheat and use our free CDM notification calculator, or you can keep reading.

The first part is pretty easy to get your head around, 30 working days with more than 20 workers at any point.

It is important to remember that working days includes "any day on which construction work takes place", so this would include weekends if work is carried out then, and also even if work is only carried out for part of the day, this should be considered a full working day in your calculation.

But what about the second part? Exceeds 500 person days, how do we calculate that?

If you are only ever going to have less that 20 workers on site, this is the notification threshold you should be considering.

Does your project exceed 500 person days?

To calculate this you need to consider how many people you will have on site, and then multiply that by the number of days they will be on site.

10 people working for 60 days? 10 x 60 = 600 person days. This project is notifiable.

5 people working for 102 days? 5 x 102 = 510 person days. This project is notifiable.

2 people working for 20 days? 2 x 20 = 40 person days. This project is not notifiable.

Be aware, however, that unlike CDM 2007, under CDM 2015 notification status no longer triggers additional duties. If your project is non-notifiable, you still must comply with all the other duties under CDM 2015, the only difference being you don't have to complete the F10 notification form.

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