CDM 2015 Construction Phase Plan: What It Is and What the Law Requires
The construction phase plan is the one document CDM 2015 requires on every single construction project, no matter how small. Yet it is also the document people most often get wrong, either skipping it on a small job or padding it into a folder nobody reads. This guide explains what the law actually requires: what a construction phase plan is, when you legally need one, who has to write it, and what it must contain, so you can produce one that holds up rather than guessing.
What a construction phase plan is under CDM 2015
A construction phase plan sets out the health and safety arrangements for a construction project during the building work itself. It records the significant risks on the job and how they will be managed, so that everyone on site works to the same plan. It is defined in Regulation 12 of the Construction (Design and Management) Regulations 2015 and is the practical bridge between the pre-construction information gathered beforehand and the way the site is actually run.
It is not a generic risk assessment library and it is not a health and safety policy. It is specific to one project, written before work starts, and kept live for the length of the build.
When you legally need a construction phase plan
Always. This is the point most people miss. Under Regulation 12, a construction phase plan must be drawn up for every construction project, whether it is a single-contractor kitchen extension or a multi-contractor commercial build, and whether or not the project is notifiable to the HSE. There is no minimum size below which the requirement disappears.
The timing matters just as much as the existence of the plan. It must be prepared before the construction phase begins, that is, before anyone sets up the site or starts the work. A plan written after the job has finished, to fill a gap in the paperwork, does not meet the regulation and offers no protection to the people who were on site.
Who writes the construction phase plan
The answer depends on how many contractors are on the project, and CDM 2015 is precise about it.
- One contractor on the project. The contractor draws up the construction phase plan, or arranges for it to be drawn up.
- More than one contractor. The principal contractor draws up the plan, and must do so before the site is set up. The principal contractor also keeps it under review and updates it as the project changes.
In both cases the plan should draw on the pre-construction information the client provides, so the people doing the work are not starting from a blank page on the hazards that were already known.
What a construction phase plan must contain
CDM 2015 does not hand you a rigid template, but HSE guidance L153 is clear about what a proportionate plan covers. It should set out the arrangements for managing the work and the specific health and safety risks the site presents.
- The project itself. A description of the work, the key dates, and the people carrying the CDM duty holder roles.
- Management arrangements. How health and safety will be managed on site, including site rules, induction, welfare and how information is shared.
- The significant risks. The health and safety hazards specific to this site and the control measures for each, not a library of every conceivable risk.
- Proportion to the job. A domestic loft conversion needs a short, focused plan; a large multi-contractor project needs a fuller one. The test is that it matches the real risks, not its page count.
Keeping the plan alive
A construction phase plan is a living document, not a one-off submission. As the work moves through its stages, new risks appear and old ones fall away, and the plan has to keep pace. On a multi-contractor project the principal contractor is responsible for reviewing and revising it throughout the build. A plan that was accurate on day one but was never touched again is a plan that has stopped protecting anyone.
Frequently asked questions
Is a construction phase plan a legal requirement?
Yes. Regulation 12 of CDM 2015 requires a construction phase plan for every construction project, regardless of size and whether or not the project is notifiable to the HSE. It must be prepared before the construction phase begins, meaning before the site is set up and work starts.
Who writes the construction phase plan under CDM 2015?
On a project with only one contractor, that contractor draws up the plan. On a project with more than one contractor, the principal contractor draws it up before the site is set up and keeps it under review. In both cases the plan should use the pre-construction information the client provides.
What must a construction phase plan contain?
Following HSE guidance L153, a construction phase plan should describe the project and duty holders, set out how health and safety will be managed on site, and identify the significant site-specific risks with the control measures for each. It must be proportionate to the work, so a small job needs a short focused plan rather than a generic folder.
The shortcut
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This article is general guidance for UK construction and is not legal advice. For requirements specific to your work, check the full text of CDM 2015 and current HSE guidance, including L153, and your own duty holder obligations.