The 30-day assumption on a gym conversion
You are site manager for a contract converting a vacant retail unit into a gym for a private developer: two load-bearing walls out, a new steel-framed mezzanine in. The programme shows 35 working days on site and peak occupancy of 22 operatives; the tender estimate is 560 person-days. Contract, appointments and pre-construction information are all filed. On your first walk-round you find the structural alterations have already started, there is no construction phase plan in the folder, and the developer's project manager emails: 'It's under 30 days, so no F10 and no principal designer needed - we've built two of these without one.' Your employer holds the principal contractor appointment.
1. Is this project notifiable to HSE? Show your reasoning against the CDM 2015 test and say who carries the legal duty to make sure notification happens.
Read the worked answer
Work the test as two alternative limbs, not a checklist that must all be met:
- Limb 1: more than 30 working days and more than 20 workers simultaneously at any point. Here 35 days (>30) and 22 workers (>20) - met on both counts.
- Limb 2: the project exceeds 500 person-days. Here 560 - met independently.
So the PM is wrong twice over. 'Under 30 days' is not the test, and even if the duration limb had failed, the person-day limb catches it.
The duty sits with the client. The client must ensure the notification is made; in practice the principal designer or principal contractor submits the F10, but the client cannot delegate the accountability away. Your action is therefore not to overrule the PM, but to put the calculation in writing to the client and PM, offer to submit the F10 on their behalf with their written confirmation, and record the advice given. That protects the client, your employer and you. An unnotified notifiable project is also evidence that the client's arrangements for managing the project are not suitable - worth raising while you have their attention.
2. The structural alterations have started with no construction phase plan. What is your position, and what do you actually do on Monday morning?
Read the worked answer
The principal contractor must draw up the construction phase plan before setting up the site and before the construction phase begins. That has not happened, so the site is being run outside the legal framework.
But the decisive issue is not the paperwork gap, it is what the paperwork gap conceals: load-bearing walls are being removed with no recorded temporary works design, no sequence, no checking regime and no emergency arrangements. That is a collapse risk to everyone in the unit and possibly to the structure next door.
Monday morning:
- Stop the wall removal and anything that depends on it. Not the whole site - you can keep low-risk work going under your own supervision.
- Get the temporary works design, the sequence and the checking regime from a competent temporary works engineer, and a plan that covers the demolition, the retained structure and the interface between them.
- Draw up the construction phase plan - proportionate, site-specific, including management structure, welfare, site rules, first aid, emergency arrangements and the demolition sequence - and brief it out before restarting.
- Escalate in writing to your contracts director and the client, explaining the stop, the restart criteria and the dates. Commercial pressure is not a defence, and a written record of a reasoned decision is what stands up later.
3. What duty holder appointments does this project need, and what would change if the works had been let to a single contractor?
Read the worked answer
Because more than one contractor is involved (demolition, steelwork, fit-out trades), the client must appoint both a principal designer and a principal contractor, in writing. Check the paperwork actually says this - a framework agreement and a purchase order are not the same as the appointment.
- Principal designer: coordinates health and safety in the pre-construction phase, and typically starts the health and safety file (the client's duty is to ensure the file is prepared, kept available and handed over).
- Principal contractor: plans, manages and monitors the construction phase, draws up the construction phase plan, coordinates contractors, provides welfare and controls site access.
- Client: makes suitable arrangements for managing the project and ensures sufficient time and resources are allocated - a 35-day programme for this scope is worth testing against that duty.
If there had been only one contractor, no principal designer or principal contractor appointments would be required; that single contractor would carry the duties of both. The client's own duties do not disappear in that case - they simply fall to be discharged with fewer people involved.