A construction phase plan (CPP) is the health and safety document that CDM 2015 requires for every construction project in Great Britain — from a loft conversion to a major infrastructure scheme. It sets out how health and safety will be managed during the construction phase: the arrangements, the site rules, and the control measures for the significant risks on that specific job. No construction phase plan, no lawful start on site.
This guide explains what the plan must include, who is responsible for writing it, how it differs from a construction phasing plan (a different document that often gets confused with it), and where assistive AI is starting to take the drafting burden off contractors.
What is a construction phase plan?
A construction phase plan is a written plan, required by the Construction (Design and Management) Regulations 2015 (CDM 2015), that records how health and safety will be managed while construction work is carried out. It is job-specific: it describes the project, the management arrangements, and the controls for the site’s significant risks — not a generic company policy pasted between projects.
The plan must be drawn up before the construction phase begins, and it must be treated as a living document: reviewed and updated as the work progresses and as risks change.
Is a construction phase plan a legal requirement?
Yes. Under CDM 2015 a construction phase plan is required for every construction project, regardless of size, duration or value — including domestic projects. The client has a duty to make sure a plan is drawn up before work starts; the contractor or principal contractor has the duty to actually produce it.
There is no exemption for small jobs. What changes with project size is proportionality: HSE guidance is clear that the plan should be proportionate to the scale and risk of the work. A two-day domestic refurbishment might need only a few pages (the CITB CDM Wizard app exists for exactly this); a phased demolition and rebuild in a city centre needs substantially more.
Who writes the construction phase plan?
- Single-contractor projects: the contractor draws up the plan.
- Projects with more than one contractor: the principal contractor draws it up, using pre-construction information supplied by the client and principal designer.
- The client must ensure the plan exists before the construction phase starts — on domestic projects this duty normally passes to the contractor or principal contractor.
In practice the drafting usually lands on a contracts manager, site manager or health and safety lead — often under time pressure, in the same pre-start window as RAMS, notifications and programme.
What must a construction phase plan include?
HSE’s guidance (L153) sets out the expected contents. A proportionate plan typically covers:
| Section | What it covers |
|---|---|
| Project description | The client, the team, the scope of work, key dates and programme for the construction phase |
| Management arrangements | Who is responsible for what; how the work will be organised, supervised and communicated; arrangements for cooperation between contractors |
| Site induction, training and welfare | How people are inducted, competence checks, and the welfare facilities required by Schedule 2 of CDM 2015 |
| Site rules | Access and security, traffic and pedestrian routes, PPE requirements, permits to work, emergency procedures and first aid |
| Specific risks and control measures | The significant, site-specific risks — e.g. work at height, demolition, temporary works, asbestos, services, lifting operations — and how each is controlled |
| Health hazards | Dust, noise, vibration, hazardous substances and the controls for each |
The test is usefulness, not thickness. A plan bloated with boilerplate that nobody on site reads fails at its one job: telling the people doing the work how the risks on this project are managed.
When does the plan need to be ready — and how is it kept up to date?
The construction phase plan must exist before any construction work starts, including site set-up. From there it should be reviewed and revised throughout the job: when the programme changes, when new trades or significant risks arrive, and when incidents or near misses show a control isn’t working. Records like a well-kept site diary and point-of-work checks such as POWRAs feed that review loop — they are the evidence that the plan reflects what is actually happening on site.
Construction phase plan vs construction phasing plan: what’s the difference?
The two names are one letter apart and regularly confused, but they are different documents doing different jobs:
- A construction phase plan is the CDM 2015 health and safety document described above. It is a legal requirement.
- A construction phasing plan (or sequencing plan) is a programme document: it breaks the build into phases and sets out the order and logic of the work — what gets built when, how trades overlap, how the site is zoned, and how people, plant and materials move as the job progresses. It is not required by CDM 2015, but on any complex project it drives cost, duration and buildability.
Good construction phasing and sequencing decisions — which zones open first, where the crane sits, how demolition hands over to groundworks — are among the highest-leverage choices made before work starts. They also feed the construction phase plan, because the sequence of the work determines when specific risks appear on site.
Where does AI help with phase plans and phasing?
Both documents are drafting- and analysis-heavy, which is exactly where assistive AI is starting to earn its place in contractors’ workflows:
- Drafting the construction phase plan: an AI assistant can assemble a proportionate, project-specific first draft from the pre-construction information, the scope and the programme — pulling through the right site rules and risk sections rather than recycling a generic template. A competent person still reviews, adjusts and owns the result; the gain is that they start from a structured draft instead of a blank page, the same assistive pattern as AI-drafted RAMS.
- Keeping it live: because the plan must evolve with the job, AI can flag when programme changes or diary entries imply a risk the plan doesn’t yet cover.
- Phasing and sequencing options: AI-assisted scenario modelling can compare candidate phasing strategies — durations, logistics constraints, cost implications — faster than working each option up by hand, so planners evaluate more options before committing to one.
These are emerging, assistive capabilities: the value is speed and coverage on the drafting and analysis, with judgement staying firmly with the planner, QS or safety professional. For how this pattern is playing out in one of the most safety-critical corners of the industry, see our guide to AI in demolition and the demolition operational efficiency hub.
Frequently asked questions
Do I need a construction phase plan for a small domestic job?
Yes. CDM 2015 requires one for every construction project, including domestic work. For small, low-risk jobs it can be short and simple — the CITB CDM Wizard app was built for this.
Is there a standard construction phase plan template?
HSE and CITB both publish guidance and simple templates. A template is a fine starting point, but the plan only satisfies CDM 2015 if it is made specific to your project — its risks, its site, its management arrangements.
What’s the difference between a construction phase plan and RAMS?
The construction phase plan is the project-level document covering how health and safety is managed across the whole construction phase. RAMS (risk assessments and method statements) are task-level: how one activity will be carried out safely. RAMS sit under the umbrella of the phase plan.
Who checks the construction phase plan?
The client must ensure it exists before work starts, and the principal designer assists with pre-construction information. HSE inspectors can ask to see it — an absent or plainly generic plan is a common enforcement finding.
How often should the plan be updated?
Whenever the work or its risks change: new phases, new contractors, design changes, incidents. On most live projects that means reviewing it at least at each phase boundary and after any significant programme change.
Talk to us about faster, better pre-construction documents
Surtori helps contractors use assistive AI across their operational documents and pre-construction workflow — phase plans, RAMS, POWRAs, site records and phasing analysis — with the judgement staying where it belongs. Book a discovery call to see what that looks like on your projects.