How to Write a Construction Phase Plan: A Practical Guide for UK Contractors
A Construction Phase Plan (CPP) is a legal requirement under the Construction (Design and Management) Regulations 2015 (CDM 2015) for virtually every construction project in Great Britain. If you are a principal contractor — or a contractor running a single-contractor project — knowing how to write a Construction Phase Plan properly is not just about ticking a box. Done well, it becomes a working document that keeps your site safer and your team coordinated.
What Is a Construction Phase Plan and Who Writes It?
The CPP is a document that sets out how health and safety will be managed during the construction phase. Regulation 12 of CDM 2015 places the duty to prepare it on the principal contractor (on notifiable or multi-contractor projects). Where there is only one contractor, that contractor carries the same duty.
Critically, the CPP must be prepared before the construction phase begins — not retrospectively. The client must not allow construction to start unless a CPP is in place (reg 4(4)).
It is not a static document. CDM 2015 requires the principal contractor to review, update and revise it throughout the project as circumstances change.
What Must a Construction Phase Plan Include?
CDM 2015 Schedule 3 sets out the required content. Think of it in four broad areas:
1. Project Description and Management Arrangements
- Nature and location of the project
- Details of the client, principal designer, principal contractor and key contacts
- Management structure and responsibilities (who is in charge of what on site)
- Arrangements for communication and cooperation between contractors
- Arrangements for involving workers in health and safety
2. Site Rules and Controls
- Site-specific induction arrangements
- Procedures for reporting near misses, incidents and accidents
- Rules on restricted areas, access control and permit-to-work systems
- Welfare facilities provided (the minimum requirements are set out in CDM 2015 Schedule 2)
3. Significant Risks and How They Are Managed
This is the technical heart of the document. For each significant risk on your project, apply the correct control hierarchy:
| Hierarchy Level | Example on a Construction Site |
|---|---|
| Eliminate | Redesign to remove the need to work at height |
| Substitute | Use pre-fabricated units off-site instead of in-situ cutting |
| Engineering controls | Edge protection, dust extraction, trench boxes |
| Administrative controls | Safe systems of work, permits, inductions, supervision |
| PPE | Hard hats, RPE, safety footwear — last resort only |
Typical significant risks to address include:
- Work at height — governed by the Work at Height Regulations 2005; avoid where possible, then use collective protection (scaffolding, edge protection) before personal protection (harnesses)
- Excavations — inspection, support, proximity to services
- Hazardous substances — assessed under the Control of Substances Hazardous to Health Regulations 2002 (COSHH); silica dust, cement dermatitis and asbestos are common on construction sites
- Plant and vehicle movements — segregation of pedestrians and plant
- Structural stability — temporary works, propping, demolition sequences
- Overhead and underground services — identification and safe isolation
4. Arrangements for Specific Risks and Welfare
- Fire and emergency procedures (the Regulatory Reform (Fire Safety) Order 2005 applies to common areas of construction sites; ensure your emergency plan reflects this)
- First aid provision
- Arrangements for managing subcontractors and checking their competence
Common Mistakes to Avoid
Generic, copy-and-paste plans. The HSE is clear that a CPP must be specific to the project. A plan that could apply to any site is not a suitable CPP. Tailor every section to your actual site, ground conditions, scope and workforce.
Treating it as a pre-start document only. The CPP must evolve. When new subcontractors arrive, significant risks change, or the programme shifts, update the plan and re-brief the team.
Burying it in the site office. Workers and supervisors should be able to access the relevant parts of the CPP. Key information — site rules, emergency procedures, restricted areas — should be communicated at induction and displayed where appropriate.
Confusing the CPP with a RAMS. A CPP is the overarching site management plan. Individual task-level risk assessments and method statements (RAMS) sit beneath it. They should be consistent with the CPP but are separate documents.
How Long and How Detailed Should It Be?
Proportionality is important. For a small domestic refurbishment with one contractor, a concise, well-structured CPP of a few pages may be entirely adequate. For a large civil engineering project with multiple principal contractors and complex interfaces, the document will necessarily be more extensive.
The test is not length — it is whether the plan genuinely describes how health and safety risks on your specific project will be managed.
Reviewing and Handing Over
At the end of the project, relevant parts of the CPP feed into the health and safety file compiled by the principal designer. Make sure your records, as-built information and residual risk documentation are kept in order throughout.
Writing a Construction Phase Plan that actually works means engaging with the real hazards on your site, assigning clear responsibilities, and treating the document as a live management tool rather than an administrative exercise.