What Is a Construction Phase Plan? A Plain-English Guide for UK Contractors
A construction phase plan (CPP) is a live health and safety document required under the Construction (Design and Management) Regulations 2015 (CDM 2015). It sets out how health and safety will be managed during the actual build — from the first day on site through to practical completion. If you are a contractor working on a notifiable or multi-contractor project, understanding this document is not optional.
The Legal Basis
CDM 2015 regulation 12 places the duty to prepare a construction phase plan on the principal contractor (PC) where there is more than one contractor on a project. Where there is only a single contractor, regulation 12(1) still requires that contractor to draw up and manage a CPP before the construction phase begins. There is no minimum project size that removes this duty — even a modest domestic extension with a single contractor requires a CPP if the client appoints one.
The principal designer (or designer, on single-contractor projects) does not write the CPP — that is the PC's job. The principal designer is responsible for the pre-construction information pack, which feeds into the CPP.
What Must a Construction Phase Plan Include?
CDM 2015 schedule 3 lists the required content. A practical CPP will cover:
- Project description — scope, programme, site address, key contacts
- Management structure — who is the PC, site manager, principal designer, and client; lines of responsibility
- Pre-construction information — a summary of hazard information provided by the client or principal designer (e.g. buried services, asbestos surveys, ground conditions)
- Arrangements for managing significant site risks — these are the core content; see below
- Site rules — permit-to-work procedures, induction requirements, vehicle/pedestrian segregation
- Consultation and communication — toolbox talks, site meetings, how workers raise concerns
- Emergency procedures — fire evacuation, first aid, nearest A&E
- Welfare facilities — confirming compliant provision before work begins (CDM 2015 schedule 2)
Managing Significant Risks: The Core Content
The CPP is not a form-filling exercise. Its value lies in the specific arrangements for the real hazards on your site. Typical areas to address include:
| Risk Area | What to Cover |
|---|---|
| Work at height | Collective protection (scaffold, edge protection) before individual PPE; WAH Regulations 2005 hierarchy |
| Excavations | Support systems, edge protection, inspection regime under CDM/PUWER |
| Demolition | Sequence, structural survey, dust and noise controls |
| Buried/overhead services | CAT scan results, exclusion zones, safe digging procedures |
| Asbestos | Refurbishment and demolition survey findings, licensed/non-licensed work arrangements |
| Lifting operations | Appointed person, lift plan references, LOLER 1998 compliance |
| Hazardous substances | COSHH 2002 assessments referenced or appended |
| Fire | Site fire emergency plan (note: the Regulatory Reform (Fire Safety) Order 2005, administered by the Home Office, applies to non-domestic sites in use; the CPP should cross-reference your site fire plan) |
Controls should follow the hierarchy: eliminate the hazard first, then substitute, then engineering controls, then administrative controls, with PPE as a last resort — not the other way around.
When Must the CPP Be Ready?
Regulation 12(1) is clear: the construction phase must not begin until the CPP has been prepared. It does not need to be a finished document in every detail at day one — the HSE acknowledges it is a live plan — but it must be sufficiently developed to manage the foreseeable risks of the early works before anyone sets foot on site.
Who Else Needs to See It?
The CPP must be made available to every contractor working on the project. Each sub-contractor's RAMS (their own risk assessment and method statement) should be consistent with the CPP — not contradict it. During an HSE inspection, the site manager should be able to produce the current version quickly. An out-of-date document sitting in a drawer is a common enforcement finding.
Keeping It Live
This is the point most contractors miss. The CPP must be reviewed and updated as the project develops. When a new work package begins, when site conditions change, or when an incident or near-miss occurs, the plan should be revised. A CPP written on day one and never touched again does not meet the regulation's intent.
Practical triggers for a review include:
- A new sub-contractor mobilising with unfamiliar methods
- Discovery of unexpected ground conditions or services
- A change in programme that affects sequencing of high-risk work
- Any reportable incident under RIDDOR 2013
Proportionality
The HSE is explicit that the CPP should be proportionate to the project. A short-duration domestic refurbishment needs a simpler, shorter plan than a large commercial build. Lengthy generic documents copied from a template do not constitute compliance and can actually obscure the real hazards. Focus on what is genuinely significant on your specific site.
A Quick Summary
- Required by CDM 2015 reg 12 on every construction project with a contractor
- Written by the principal contractor (or sole contractor)
- Must exist before construction begins
- Covers management arrangements, significant risks, site rules, welfare and emergency procedures
- Must be proportionate, site-specific, and kept up to date throughout the project
Getting the CPP right from the start sets the tone for how health and safety is actually managed on site — which is the whole point.