The advice on the HSE web site gives a different answer to Bob's comment, in the FAQ it states :- Question Is my project ‘notifiable’? Answer A project is notifiable to HSE if the construction phase will be longer than 30 days, or 500 person days of construction work, except where there is a domestic client. Any day on which construction work takes place is counted. What matters is how many days of construction work the project entails, not when these days occur or the start and finish dates. For example: 1 person working for 31 days (actual construction work) – notifiable. 60 people working for 10 days = 600 person days (based on an 8-hour day) – notifiable. 90 people working 3 x 8-hour shifts (30 per shift) for 6 days = 540 person days – notifiable. 30 people working 3 x 8-hour shifts (10 per shift) for 10 days = 300 person days – not notifiable. Work carried out before the construction phase begins should not be included. Its been several years since I've been involved with a project that came under CDM, but I remember there being something in the CDM regs about them not applying if less than 5 people would be carrying out construction work. I was not sure if this still applied under the 2007 regs but a quick check of http://www.qub.ac.uk/saf...managing_contractors.pdf and it appears to still be the case, (see page 12). This contradicts the HSE own answer to the FAQ I have pasted above as there they state 1 person working 31 days is notifiable. No wonder there is confusion whether a project is notifiable when the HSE's own advise appears to contradict itself.