What is a Construction Phase Plan and why it matters under CDM 2015
Under CDM 2015 Regulation 15, a written Construction Phase Plan should be in place before the construction phase starts. Whether you're building a house extension for a homeowner or running a larger commercial development, the CPP sits high in the documentation hierarchy and sets the framework within which contractors' RAMS should operate. If a contractor's RAMS conflicts with the project CPP or site rules, that conflict should be resolved before work starts.
The CPP isn't the same as RAMS. RAMS documents are prepared by contractors for specific tasks — how an individual contractor will carry out their particular work safely. The CPP is the principal contractor's document for managing health and safety across the entire project. It's the umbrella that everything else fits under.
The legal duty to prepare a CPP sits with the principal contractor on projects involving more than one contractor. On single-contractor domestic or commercial projects, that contractor usually prepares the CPP. The client must make suitable arrangements for managing the project, which in practice generally means ensuring the CPP has been prepared before construction starts. This isn't a paperwork exercise — the CPP needs to reflect how the project will actually be managed. An inadequate CPP that doesn't address the real hazards of the project may still be challenged, regardless of how many pages it runs to.
When a Construction Phase Plan is legally required
Under CDM 2015, a CPP is generally expected for construction projects, with the main distinction being who prepares it. On single-contractor projects — whether domestic or commercial — that contractor prepares the CPP. On projects with two or more contractors, the principal contractor appointed by the client prepares the CPP before the construction phase begins.
CDM 2015 introduces the concept of notifiable projects. A project is notifiable to HSE if it involves more than 30 working days of construction work with more than 20 workers simultaneously, or more than 500 person-days of construction work in total. Notifiable projects must be notified to HSE via the F10 form before construction begins. But — and this is important — a CPP is required for all construction projects, notifiable or not. The notifiability threshold relates to client notification duties, not to the CPP requirement itself.
For domestic clients — homeowners having work done on their property — the duty to prepare the CPP passes to the principal contractor if one is appointed. If no principal contractor is appointed, the contractor prepares the CPP. CDM 2015 allows domestic clients to be exempt from certain CDM duties, but the contractor's obligation to prepare and follow a CPP remains regardless.
The CPP must be sufficiently developed before construction starts. A CPP written on the first day of construction, after work has already begun, isn't compliant. The plan must reflect genuine thought about how the project will be managed — its hazards, its structure, its emergency procedures, and its welfare arrangements. The principal contractor should review and update the CPP as the project progresses and the work evolves.
Who is responsible for the Construction Phase Plan
On single-contractor projects, the contractor is both the preparer and the sole duty holder for the CPP. They must prepare the plan, implement it, and ensure it's reviewed and updated throughout. For multi-contractor projects, the principal contractor takes responsibility. This is one of the principal contractor's most important CDM 2015 duties.
The client also has duties. Under CDM 2015 Regulation 8, the client must ensure the principal contractor prepares the CPP and that it's appropriately reviewed and updated. The client must ensure the CPP is in place before the construction phase begins. The client doesn't prepare the CPP — that duty sits with the principal contractor — but the client must satisfy themselves that it exists and is adequate.
Where a principal designer is appointed, they contribute to the CPP by providing pre-construction information — the information about the project and the site that informs the CPP's content. They also advise the client on the adequacy of the CPP. But the principal designer doesn't prepare the CPP. That remains the principal contractor's responsibility.
Sub-contractors don't prepare their own CPP for the overall project. However, every sub-contractor must prepare RAMS for their own work — task-specific risk assessments and method statements that sit within the framework established by the CPP. If a sub-contractor's RAMS proposes a method that conflicts with the CPP's site rules or management arrangements, the principal contractor must resolve the conflict before approving those RAMS.
Minimum content of a Construction Phase Plan under CDM 2015 Schedule 3
CDM 2015 Schedule 3 specifies the minimum content of a CPP. This isn't an exhaustive list — the CPP must contain sufficient information to manage the health and safety risks of the specific project. Schedule 3 requires:
The level of detail in the CPP must be proportionate to the size and complexity of the project. A small domestic extension requires a simpler CPP than a major infrastructure project, but both should address each Schedule 3 heading in a way that matches the project's risks and complexity. Proportionality applies to the depth of detail, not to whether the core topics are considered at all.
How to write a CPP that passes client and HSE review
One of the most common reasons a CPP is challenged is generic content. A CPP that reads as if it was generated from a template and reused for every project suggests that the principal contractor has not planned this specific project properly. A CPP that names the actual site, the actual client, the actual programme, and the actual hazards — even if it's shorter than a generic template — is more likely to stand up to review because it demonstrates genuine planning.
The project description section must name the specific project and location. "The construction of a single-storey domestic extension" is a project description. "The construction of a 45m² single-storey rear extension to 14 Oak Road, Manchester" is a site-specific project description. The programme section must include actual key dates — not just "start date to completion date" but the dates of significant stages: demolition, substructure, superstructure, first fix, second fix, and completion.
The management structure must name actual people — not just "site manager" but "John Smith, CSCS Gold Card, SMSTS-certified, tel: 07700 000000." For multi-contractor projects, the principal contractor must identify the key contacts for each trade contractor. The emergency procedures section must name the specific assembly point, the specific site address that will be given to emergency services, and the names of the first aiders.
Welfare facilities should be confirmed as in place before construction begins. The CPP should state what welfare facilities will be provided — toilets, washing facilities, changing rooms, a rest area, access to hot water — and make clear they meet the relevant CDM welfare standards. A CPP that says "welfare facilities to be provided" without confirming what is actually available is likely to be challenged as too vague.
Site rules — why they matter and how to set them properly
Site rules are one of the most important — and most commonly neglected — elements of a CPP. Site rules translate the general requirements of health and safety law into specific requirements that apply to this specific site. They must be clear, enforceable, and communicated to every person who works on the site.
Effective site rules address the specific hazards and conditions of the site. A site adjacent to a main road has different rules from a site in a residential cul-de-sac. A site with overhead power lines has different rules from one without. A site with significant temporary works has different rules from one without.
Site rules should cover: PPE requirements specific to the site — what PPE is mandatory beyond the legal minimum; site access and hours of work — when the site is open, how visitors are managed; site vehicle rules — speed limits, designated pedestrian routes, reversing procedures; restrictions on specific activities — such as hot works permits, works affecting neighbours, or restrictions on particular equipment; and any permit-to-work systems that will operate on the site — for hot works, excavation, work at height, or confined space entry.
Site rules should be communicated to every worker before they start on site. The site induction is usually the mechanism for this communication. The induction should cover the site rules — not just read them from a sheet, but explain what they mean in practice and what happens if they're not followed. If a worker has not received an induction, it becomes much harder to show the site rules were properly communicated.
Emergency procedures in the Construction Phase Plan
The CPP must include arrangements for managing emergencies throughout the construction phase. These arrangements must be specific to the site — not generic statements about following procedures.
The emergency arrangements must identify: the fire assembly point — a specific named location, away from buildings and vehicle routes; the site address for emergency services — which must be displayed at the site entrance and in the site office; the first aiders on site — names and locations; the location of first aid kits, fire extinguishers, and other emergency equipment; and the procedure for contacting emergency services — how to call 999, who meets the emergency services and briefs them on arrival.
For larger sites, the emergency arrangements must address more complex scenarios: vehicle incidents — what to do if a vehicle strikes a worker or member of the public; structural collapse — how workers evacuate and who coordinates the emergency response; and multiple casualties — how the site manages more than one casualty simultaneously.
The emergency arrangements must be reviewed and updated when the site layout changes significantly. A site emergency plan written at the start of a project may not be adequate once the project has moved into a new phase with different hazards and a different layout. The principal contractor must review the emergency arrangements at each stage of the project.
The relationship between the CPP and contractor RAMS
The CPP and RAMS are complementary documents with different purposes. The CPP is the principal contractor's document for the whole project. RAMS are contractors' documents for their specific tasks. The CPP sets the framework; RAMS operate within it.
When a contractor submits RAMS to a principal contractor for approval, the principal contractor checks that the RAMS are consistent with the CPP. If the RAMS propose a method of work that conflicts with the CPP's site rules — for example, a RAMS that doesn't reference the hot works permit system — the principal contractor returns the RAMS for revision.
The CPP must also reference the key RAMS documents that will operate on the project. For high-risk activities — working at height, excavation, confined space entry, and asbestos — the CPP should identify which contractors will be carrying out this work and confirm that their RAMS have been approved before the work commences.
Both documents should be readily available on site, or otherwise quickly accessible, if HSE or project stakeholders need to inspect them. The CPP should be reviewed and updated as the project progresses. RAMS should also be reviewed and updated when the method of work changes or when new hazards are identified.
Build contractor RAMS that can be aligned to the project CPP
RAMS Builder helps contractors draft RAMS that can be aligned to a project's CPP framework. You can use it to capture site rules, emergency arrangements, and project-specific controls in contractor RAMS before submission. Describe your project, your role, and the work you will carry out, then review and tailor the document against the actual CPP, site rules, and permit systems before you submit it.
Notifiable Projects and the F10 Form — When to Notify HSE
The Construction Phase Plan is generally required for construction projects, but certain projects must also be formally notified to the Health and Safety Executive. Under CDM 2015, a project is notifiable if it involves more than 30 working days of construction work with more than 20 workers on site simultaneously, or more than 500 person-days of construction work in total. Notifiable projects must be notified to HSE using the F10 form before construction begins.
The F10 notification is the client's responsibility — or the principal contractor's if the client has transferred this duty. However, contractors working on projects that clearly meet the notifiability thresholds should satisfy themselves that the notification has been made before commencing work. Starting work before a notifiable project's notification arrangements have been dealt with can expose duty holders to enforcement action.
Even when a project isn't notifiable, a CPP may still be needed under CDM 2015. The notifiability threshold determines notification duties — it doesn't decide the wider planning duties on its own. A 25-day project with 15 workers on site simultaneously doesn't require an F10 notification, but the principal contractor may still need a CPP. Always check the project setup against CDM 2015 Regulation 15 and the actual roles involved.