What Is a Construction Phase Plan — and Do You Need One?
The Construction Phase Plan (CPP) is one of those documents that many clients have never heard of — but which their principal contractor is legally required to produce before any notifiable construction work starts. Understanding what it is, who produces it, and why it matters helps you assess whether your contractor is operating properly.
The Legal Basis
Under the Construction (Design and Management) Regulations 2015 (CDM 2015), the principal contractor must prepare a Construction Phase Plan before the construction phase begins. The plan must be reviewed, updated, and revised throughout the project as circumstances change.
CDM 2015 applies to virtually all construction work in the UK. For domestic clients, the threshold for formal notification to the Health and Safety Executive (HSE) is projects lasting more than 30 working days with more than 20 workers simultaneously, or projects exceeding 500 person-days. Below these thresholds, HSE notification isn't required, but the duty to have a CPP remains.
What a Construction Phase Plan Contains
A well-prepared CPP covers: a project description and key contacts (client, principal contractor, principal designer, relevant specialists); the management structure and responsibilities for health and safety on site; arrangements for managing risks specific to the site and project; how the site will be secured, controlled, and managed; welfare facilities; how emergency procedures and first aid will be handled; arrangements for managing subcontractors and self-employed workers; how design changes during construction will be managed; and how information will be communicated to the workforce.
The CPP is a live document — not a box-ticking exercise. A good CPP is updated as the project progresses, particularly when significant changes occur to the programme, scope, or site conditions.
Why It Matters in Practice
On a well-run project, the CPP serves as the site management framework. It means that everyone working on site — from the main contractor's supervisors to visiting subcontractors — is operating within the same understood structure. When something unexpected happens on site, the CPP provides the reference point for how to respond.
From the client's perspective, a contractor who can produce a proper CPP before work starts is demonstrating that they have thought carefully about how to run the project safely and professionally — not just how to complete the physical works.
What to Ask Your Contractor
Before works start, ask your principal contractor for a copy of the Construction Phase Plan. You don't need to read it line by line, but the fact that it exists — and is specific to your project rather than a generic template with the names swapped — tells you something important about how they operate.
If a contractor has never heard of a Construction Phase Plan, or tells you it's not required for your project when multiple contractors are involved, that's a significant warning sign.
RCB produces a project-specific Construction Phase Plan on every project as part of our principal contractor scope. It's not an afterthought — it's part of how we set up and run every job from day one.
07359 872594 | contact@rcbgroup.co.uk | www.rcbgroup.co.uk