The Construction Phase Plan Under CDM 2015: What It Must Contain and How to Keep It Alive

Every Project. Not Just the Notifiable Ones.

The single most misunderstood fact about the construction phase plan is its scope. Under CDM 2015 a CPP is required for every construction project — the domestic extension, the two-day drainage repair, the multi-year treatment works upgrade. What changed in 2015 was not whether you need one but who writes it and how big it should be: the principal contractor draws it up where there is more than one contractor; a sole contractor draws it up themselves; and the plan must be in place before the construction phase begins. The client's duty is to ensure that happens — construction starting without a CPP is a client failure as well as a contractor one.

The other misunderstanding is size. The regulations and the supporting guidance in L153 are explicit that the plan must be proportionate to the risk. A drainage repair's CPP can be a few pages; CITB's CDM Wizard exists precisely so small jobs get a real, relevant plan instead of nothing. The 200-page plan assembled by copy-paste for a small job is not compliance — it is camouflage, and it buries the ten sentences that actually matter.

What the Plan Must Cover

CDM 2015 requires the plan to record the health and safety arrangements and site rules for the construction phase, taking account of the industrial activities on site, and where relevant it must address the specific hazard areas listed in Schedule 3 — the work involving particular risks such as work near high-voltage lines, risk of drowning, contaminated land, and heavy prefabricated elements. In practical terms a competent CPP answers these questions:

The project: what is being built, where, by whom, on what programme, and who holds each CDM duty — client, principal designer, principal contractor, contractors. Management arrangements: how health and safety is organised and communicated — inductions, briefings, coordination and progress meetings, how contractors' RAMS are reviewed and accepted, how design changes reach the people they affect, welfare provision, emergency procedures, first aid, fire arrangements, accident and near-miss reporting. Site rules: the specific local law of this site — traffic and pedestrian routes, exclusion zones, permit-to-work activities, PPE standards, deliveries, working hours, security. The significant hazards and their controls: not a hazard encyclopedia, but this project's serious risks — the live services crossing the site, the deep excavations, the crane oversailing the road, the interface with an operational facility — each with the management approach that will control it.

The pre-construction information from the client and principal designer feeds directly in: existing services, ground conditions, asbestos surveys, restrictions. A CPP that does not reflect the pre-construction information is a plan for a different site.

The Plan Is a Working Document or It Is Nothing

CDM requires the plan to be reviewed, updated and revised so it remains sufficient throughout the project — and this is where most CPPs die. Version 1 is written for mobilisation, filed, and exhumed eighteen months later for an audit, by which point the site it describes no longer exists: the compound has moved, phases 2 and 3 have started, three new subcontractors have arrived, and the traffic management bears no resemblance to the drawing in Appendix C. An out-of-date CPP is worse than useless in an investigation, because it documents that the stated arrangements were not the real ones.

Keeping it alive is a discipline, not a rewrite: set review triggers — new phase, new principal hazard, significant change to site layout or management arrangements, learning from an incident — and make the review a standing agenda item at a monthly meeting. Revise the sections that changed, bump the revision, and re-brief the changes to the people affected. The revision history itself becomes evidence of a managed project.

Distribution: The Plan People Have Actually Seen

A CPP locked in the site manager's drawer protects nobody. The arrangements and site rules in it are only real if the workforce knows them — which is what the induction is for — and if every incoming contractor receives the current revision before they start, not revision 1 from the tender pack. On multi-contractor sites the distribution question is worth treating formally: who has which revision, who has confirmed receipt, and how supervisors get the relevant updates to their gangs. When the HSE inspector or the client's auditor asks an operative about the site's emergency arrangements and gets the right answer, that is the CPP working. When they get a shrug, the document's word count is irrelevant.

A Practical Standard to Hold Yourself To

Three tests tell you whether your CPP is doing its job. Currency: does the plan describe the site as it is this week — layout, phases, contractors, principal hazards? Proportionality: could a new supervisor read the parts that matter in one sitting and know how this site runs? Penetration: do inductees and subcontractors actually receive and understand the arrangements that affect them? Pass all three and the CPP is what CDM intended — the living management plan for the construction phase. Fail them and it is shelf-ware with a signature on it, and the gap between the two is where prosecutions live.