CDM Construction Phase Plan: What It Is, Free Template, and How to Write One

A construction phase plan is the health and safety document that the principal contractor must prepare before any construction work starts on a project under the Construction (Design and Management) Regulations 2015 (CDM 2015). It sets out how the specific risks of the project will be managed during the build: the site rules, the arrangements for controlling significant risks, the site set-up, and who is responsible for what. It is a legal requirement on every construction project in Great Britain, however small, and work must not begin until it is in place.

This guide explains exactly what a construction phase plan must contain, gives you a free construction phase plan template, walks through a worked UK example, and shows how to turn a day-long drafting job into a task of well under an hour with AI.

What is a construction phase plan?

The construction phase plan is one of the three key CDM 2015 documents, alongside the pre-construction information (produced by the client) and the health and safety file (handed over at the end for the finished structure). The construction phase plan is the middle document: it takes the hazards and information identified before the job starts and translates them into practical arrangements for keeping people safe while the work is carried out.

Regulation 12 of CDM 2015 requires the principal contractor to draw up the plan, or review and update it, so that it is appropriate to the work and covers the health and safety arrangements and site rules for the construction phase. On a single-contractor project (where there is only one contractor), that contractor takes on the duty and must still prepare a plan.

The key points that trip people up:

• It is required on every project. There is no lower threshold. A two-day domestic bathroom refit needs a construction phase plan just as a £50m hospital does. What changes is the depth, not the existence, of the plan.
• It must exist before work starts. The plan is drawn up during the pre-construction phase and must be ready before anyone sets foot on site to build.
• It is a living document. It is not written once and filed. It is reviewed and updated as the work progresses, risks change, and new contractors arrive.
• It must be proportionate. The HSE is explicit that the plan should be proportionate to the scale and risks of the job. A small, low-risk project does not need a 60-page document.

Who is responsible for the construction phase plan?

Under CDM 2015 the duty sits with the principal contractor on projects involving more than one contractor. Where there is only one contractor, that single contractor must prepare the plan. The client has a duty to make sure a plan is prepared before the construction phase begins, and the principal designer supports the process by passing on the pre-construction information that feeds it.

A common misunderstanding is that the plan is a health and safety consultant's document. It is not. It belongs to the contractor doing the work, because they are the ones who understand the sequence, the trades, and the practical site arrangements. A consultant can help, but the responsibility and the knowledge sit with the contractor.

What must a construction phase plan include?

The HSE guidance (L153, the official CDM 2015 guidance) sets out what the plan should cover. A complete construction phase plan addresses the following areas.

Project description and key details

The basics: project name and address, a short description of the works, the programme and key dates, and the client, principal designer, and principal contractor details. This section anchors the plan to the specific job.

Management of the work

How the project will be managed for health and safety. This includes the management structure and responsibilities, the health and safety goals for the project, the arrangements for site inductions, ongoing information and training, welfare facilities, and the arrangements for cooperation and coordination between contractors. It also covers how the workforce will be consulted and how the plan itself will be reviewed and communicated.

Site rules

The specific rules everyone on site must follow: PPE requirements, permit-to-work systems, restricted areas, speed limits for site traffic, sign-in procedures, and the arrangements for visitors. Site rules are the everyday behavioural controls that keep the site safe.

Arrangements for controlling significant site risks

This is the heart of the plan and where proportionality matters most. It sets out the arrangements for controlling the significant health and safety risks the project actually presents. Typical risks to address include:

• Safety risks: delivery and removal of materials (including waste), dealing with services (overhead lines, buried cables, gas), working at height, work over water, excavations and ground conditions, traffic management and pedestrian segregation, storage of hazardous materials, temporary works and stability, lifting operations, and fire.
• Health risks: exposure to silica dust and other dusts, asbestos, noise, hand-arm vibration, manual handling, hazardous substances (COSHH), and physical demands of the work.

Crucially, the plan should only cover the risks that are significant for that particular project. Listing generic hazards that do not apply is one of the most common ways plans become bloated and useless.

The site set-up and welfare arrangements (access and egress, site boundaries and security, welfare facilities, first aid, and emergency procedures including fire) are usually documented here or in a dedicated section.

Construction phase plan vs RAMS vs pre-construction information

These documents are related but distinct, and confusing them is a frequent source of trouble on site.

The simplest way to hold the distinction: the pre-construction information is the input, the construction phase plan is the project-wide plan, RAMS are the task-level detail, and the health and safety file is the legacy document. The construction phase plan sits above individual RAMS. It sets the framework, and the RAMS from each trade fill in how their specific work will be done. You can see our guides on what a RAMS is and how to write a method statement for the task-level documents that sit underneath the plan.

A worked construction phase plan example

Here is a shortened, realistic example for a small UK project, to show the level of detail a proportionate plan needs.

Project: Two-storey rear extension and internal alterations, 14 Millfield Road, Leeds Client: Private domestic client (via appointed contractor as principal contractor) Principal contractor: Northgate Building Contractors Ltd Programme: 9 weeks, starting Monday 3 August 2026 Notifiable: No (under 30 working days and fewer than 20 workers at once, and under 500 person-days)

Management of the work: Site manager (M. Ellis) responsible on site daily. All operatives and visitors inducted before first access. Weekly site walk and toolbox talk. Plan reviewed at each stage change (demolition, groundworks, structure, roofing, fit-out).

Site rules: Hard hats, hi-vis, and safety boots at all times in the work area. No lone working during demolition or roofing. Home occupied during works, so the family's access route to the front of the house is segregated with Heras fencing and kept clear. Skip and deliveries managed to avoid blocking the shared driveway.

Significant risks and arrangements:

• Working at height (roofing, first-floor structure): scaffold designed and erected by a competent contractor, inspected before use and every 7 days, records kept. Edge protection to first-floor slab.
• Demolition of rear wall: temporary propping to the design of a temporary works engineer before removal. Exclusion zone maintained. Occupied dwelling, so dust sheeting and structural monitoring in place.
• Silica dust (chasing, cutting blocks): on-tool extraction and water suppression, FFP3 masks, face-fit tested. See COSHH assessments in RAMS.
• Buried services: CAT scan and service drawings before excavation for the new foundations. Hand-dig trial holes near the known gas run.
• Fire and occupied premises: the family remain in the front of the house. Clear escape route maintained at all times, hot works permit required, extinguishers on site, and the client briefed on the site emergency arrangements.

Welfare: Portable welfare unit with WC, wash facilities, and a rest area on the driveway for the duration. First-aider on site; nearest A&E noted.

Notice how short this is, yet it names the real risks of this specific job: an occupied dwelling, temporary works for the demolition, silica, and buried services. A plan that instead listed forty generic hazards with none of this project-specific detail would be worse, not better.

How to write a construction phase plan in minutes with AI

The reason construction phase plans are so often thin, generic, or copied wholesale from the last job is that they are time-consuming to write well, and small contractors rarely have a dedicated health and safety team. AI changes the economics of this. It will not replace your judgement about the risks, but it will do the structuring, drafting, and formatting that eats the hours.

The workflow is straightforward:

1. Gather the inputs. The pre-construction information from the client, the outline programme, the list of trades and activities, and the significant risks you already know the job carries.
2. Prompt the AI with the project specifics. Give it the project description, the sequence of works, and the significant risks, and ask it to produce a construction phase plan structured to CDM 2015 and HSE L153 guidance, covering project details, management of the work, site rules, and arrangements for controlling the significant risks you listed.
3. Review hard against reality. This is the essential step. Check that every risk it addresses actually applies to your site, that it has not invented arrangements you cannot deliver, and that nothing significant is missing. Delete generic filler.
4. Add the site-specific detail only you know. Access constraints, neighbours, occupied premises, awkward deliveries, the things that make this job different.
5. Attach the supporting documents. The site layout, the RAMS from each trade, and the relevant assessments.

The AI gives you a complete, well-structured first draft in a couple of minutes instead of a blank page. You spend your time on the part that matters, which is the judgement about what is actually risky on this job and how you will control it. Our create waste management plan workflow covers a related CDM document, our draft method statement workflow produces the task-level RAMS that sit under the plan, and the full set of construction prompts is in the BuildCopilot Prompt Pack. Health and safety leads will also find the wider AI for health and safety managers collection useful.

Common construction phase plan mistakes

• Copying the last project's plan without editing it. A generic plan that does not reflect this project's real risks is arguably worse than none, because it looks like compliance while providing no actual control. The HSE looks for a plan that fits the job.
• Writing it after work has started. The plan must be in place before construction begins. A plan produced retrospectively fails its whole purpose.
• Making it disproportionately long. A 60-page plan for a small refurbishment buries the important controls in generic boilerplate. Proportionate means covering the significant risks properly and nothing more.
• Treating it as a filing exercise. The plan has to be communicated to the workforce and used. A plan nobody on site has read does not protect anyone.
• Never updating it. Risks change as the job moves through demolition, structure, and fit-out. A static plan drifts out of date. Review it at each stage.
• Confusing it with RAMS. The plan is the project-wide framework; the RAMS are the task detail. You need both, and one does not replace the other.

When is a project notifiable?

Separate from the plan, a project must be notified to the HSE (using form F10) if the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or exceed 500 person-days. Notification is the client's duty. It is worth flagging in the plan because people often conflate the two: every project needs a construction phase plan, but only larger projects are notifiable. A small extension like the worked example above needs a plan but does not need an F10.

Free construction phase plan template

Use our free construction phase plan template to give every project a consistent, CDM-compliant structure. Pair it with the AI workflow above and the task-level RAMS template, and you get a proportionate, project-specific plan without losing a day to drafting. Keep it proportionate, keep it project-specific, keep it updated, and it does exactly what CDM 2015 intends.

Frequently asked questions

What is a construction phase plan under CDM 2015?

A construction phase plan is the document the principal contractor must prepare before construction work starts, setting out the health and safety arrangements, site rules, and the arrangements for controlling the significant risks of the project. It is required under Regulation 12 of CDM 2015 on every construction project in Great Britain.

Do small projects need a construction phase plan?

Yes. There is no size threshold. Every construction project, including small domestic jobs like a single extension or a bathroom refit, needs a construction phase plan. What changes with the scale of the project is the depth and length of the plan, which must be proportionate to the risks, not whether one is required at all.

Who writes the construction phase plan?

The principal contractor writes it on projects with more than one contractor. Where there is only one contractor on the project, that contractor prepares it. It is the contractor's document because they understand the site set-up and the sequence of work; a consultant can assist, but the duty and the knowledge sit with the contractor.

What is the difference between a construction phase plan and RAMS?

The construction phase plan is the project-wide health and safety framework covering how the whole job will be managed. RAMS (risk assessments and method statements) are task-level documents produced by each contractor detailing how a specific activity will be carried out safely. The plan sits above the individual RAMS, which fill in the detail for each trade's work.

When must the construction phase plan be ready?

It must be in place before the construction phase begins, meaning before anyone starts building work on site. It is prepared during the pre-construction phase using the pre-construction information from the client, and it is then reviewed and updated as the work progresses.

Is a construction phase plan the same as notifying the HSE?

No. A construction phase plan is required on every project. Notification to the HSE (via form F10) is only required when the work will last longer than 30 working days with more than 20 workers at once, or exceed 500 person-days. Many projects need a plan but are not notifiable.