CDM 2015 Core · Mandatory · Pre-Construction

Construction Phase Plan

The Construction Phase Plan sets out the health and safety arrangements, site rules, and specific measures for managing risks during the construction phase. It must be prepared before the construction phase begins and kept updated throughout the project. This is a key document under CDM 2015 that the principal contractor must prepare.

Last reviewed: 29 March 2026 — This guide reflects UK law as of this date. CDM 2015 Reg 12 remains current with no amendments enacted as of 29 March 2026. Next scheduled review: 29 March 2027.

Legal basis	CDM 2015 Regulation 12(1) [multiple contractors] & Regulation 15(5) [single contractor]
Applies to	ALL construction projects in Great Britain — commercial and domestic, every size and duration
Key change in 2015	Before CDM 2015, CPPs were only required on notifiable projects. Since April 2015: every project.
Who produces it	Principal Contractor (multiple contractors) or sole contractor (single contractor projects)
When	Must be in place BEFORE construction work starts on site — not after
Client gate	CDM 2015 Reg 4(5)(a): clients must NOT allow work to start without a CPP in place
Mandatory?	Yes — no exceptions, no minimum size threshold. Proportionate in depth, not in existence.
Enforcing authority	Health and Safety Executive (HSE)

1. What Is a Construction Phase Plan?

If you're a contractor in the UK, the Construction Phase Plan is your site's health and safety management document. It is the document that describes — before a single spade goes in the ground — how the work will be carried out safely, who is responsible for what, what the site rules are, and how significant risks will be controlled.

The CPP is sometimes called the Construction Phase Health and Safety Plan. Whatever you call it, it is the same document: a legally required, project-specific, written plan that must exist before construction work begins.

CDM 2015 Regulation 12(2) defines what the CPP must do:

“The construction phase plan must set out the health and safety arrangements and site rules taking account, where necessary, of the industrial activities taking place on the construction site and, where applicable, must include specific measures concerning work which falls within one or more of the categories set out in Schedule 3.”— CDM 2015 Regulation 12(2)

The CPP is not a theoretical exercise. It is a working document, kept on site, that every member of the project team should be able to read and understand. The HSE is explicit: a plan that sits in a drawer unread is not a compliant plan. It must describe actual arrangements — not idealised ones — and must be updated as the project evolves.

One important distinction

The CPP is entirely separate from the Pre-Construction Information Pack (PCIP). The PCIP is produced by or on behalf of the client and describes what is already known about the site. The CPP is produced by the contractor and describes what they plan to do about it. The PCIP feeds into the CPP — you cannot write a proper CPP without first having the PCIP. They are complementary, not interchangeable.

2. Is It a Legal Requirement?

Yes — on every construction project, regardless of size, duration, value, or whether it is notifiable. This is one of the most significant changes introduced by CDM 2015, and one that many contractors still have not fully absorbed.

Critical change from CDM 2007

Under CDM 2007, Construction Phase Plans were only required on notifiable projects — those lasting more than 30 working days with 20+ simultaneous workers, or exceeding 500 person-days. Since CDM 2015 came into force on 6 April 2015, a CPP is required on EVERY construction project. A one-week bathroom refurbishment, a domestic kitchen installation, a single-day repair — all require a CPP. This is not a grey area.

The legal provisions are split across two regulations depending on project structure:

Regulation 12(1)	During the pre-construction phase, and before setting up a construction site, the PRINCIPAL CONTRACTOR must draw up a CPP, or make arrangements for one to be drawn up. Applies to projects with more than one contractor.
Regulation 15(5)	If there is only one contractor working on the project, the CONTRACTOR must draw up a CPP, or make arrangements for one to be drawn up, as soon as is practicable prior to setting up a construction site. Applies to all single-contractor projects including domestic work.
Regulation 4(5)(a)	The client must not allow the construction phase to begin unless satisfied that the principal contractor (or contractor) has prepared a suitable CPP. This creates a legal gate: work cannot legally start without a CPP being in place.
Regulation 4(4)	The CPP must be reviewed, updated and revised throughout the project so it continues to be sufficient to manage health and safety risks.

What proportionality means — and does not mean

The CPP must be proportionate to the project. A simple domestic repair does not require a 100-page plan. But proportionality applies to the depth and detail of the plan — not to whether one exists. Every project requires a CPP. What changes is how long it needs to be and how much detail it must contain.

The HSE has been clear: a CPP for a simple domestic project might be one or two pages. A CPP for a major commercial project might run to 100 pages with appendices. Both are valid, provided they address the actual risks of the actual project. What is never valid is having no CPP at all.

Project scale	Typical CPP length	Typical content
Simple domestic	1-2 pages (HSE CIS80 format)	Key dates, service locations, identified hazards, welfare arrangements, emergency contacts, site rules
Small commercial	5-15 pages	Above plus: induction procedures, subcontractor management, COSHH, working at height measures, coordination with client’s operations
Medium project	20-50 pages	Comprehensive: all sections of L153 Appendix 3, Schedule 3 risks addressed, detailed emergency plans, H&S file arrangements, traffic management
Large / complex / notifiable	50-100+ pages plus appendices	Full documentation: detailed method statements, drawings, specialist contractor arrangements, monitoring regime, change management procedures

3. Who Is Responsible?

Responsibility for the CPP depends on how many contractors are involved in the project.

Role	Responsibility under CDM 2015
Principal Contractor	On projects with more than one contractor, the Principal Contractor must draw up the CPP (or arrange for it to be drawn up) before the construction phase begins. They must ensure it is implemented, kept on site, updated as conditions change, and communicated to all workers. This is the core duty holder for the CPP on multi-contractor projects.
Sole Contractor	On single-contractor projects (including domestic work), the sole contractor takes on the duty to prepare the CPP. On domestic projects, the contractor also inherits the client’s CDM duties under Regulation 7, including the duty to ensure a CPP is in place before work starts.
Principal Designer	The Principal Designer does not produce the CPP. However, they must assist the Principal Contractor in preparing it by providing relevant design information and ensuring that pre-construction information is passed across. The PD’s role is to feed information into the CPP, not to write it.
Client	The client must not allow the construction phase to begin unless a suitable CPP is in place (Regulation 4(5)(a)). This creates a legal gate. The client does not write the CPP, but they must be satisfied it exists and is adequate before giving authority to start work.
Subcontractors	Subcontractors do not produce the CPP but must comply with it. They must provide relevant information to the Principal Contractor for inclusion — particularly regarding their specific risks, method statements, and competence. They must follow the site rules set out in the CPP.
Workers	Workers must be made aware of the CPP’s contents relevant to their work. They must follow site rules, report unsafe conditions, and cooperate with the arrangements described in the plan. The CPP must be accessible to them — not locked in a site office.

4. When Does It Need to Be in Place?

Before any construction work starts on site. This is an absolute requirement — not a target.

Work cannot legally start without a CPP

CDM 2015 Regulation 4(5)(a) creates a legal gate: the client must not allow the construction phase to begin unless satisfied that the principal contractor (or contractor on single-contractor projects) has prepared a construction phase plan that complies with Regulation 12(2). This is not advisory. If work starts without a CPP in place, both the contractor and the client are in breach of CDM 2015.

The CPP must also be kept current throughout the project. It is not a document you write once and forget. The following are common triggers for review and update:

A new subcontractor is appointed or a new trade arrives on site
The scope of work changes significantly
A new hazard is identified that was not in the original plan
An incident or near-miss reveals a gap in the existing arrangements
The programme changes and phases overlap that were originally sequential
New information emerges from the Pre-Construction Information Pack

5. What Must a Construction Phase Plan Contain?

CDM 2015 Regulation 12(2) sets the broad requirement. HSE L153 Appendix 3 provides detailed guidance on what should be included. The CPP must address the health and safety arrangements for the project, the site rules, and any specific measures for high-risk work falling within Schedule 3. It must be proportionate — but it must be comprehensive enough that anyone reading it can understand how health and safety will be managed on this specific project.

Project Description and Management

A description of the project: what is being built or refurbished, where, the key dates (start, completion, key phases), the project team and duty holders (client, principal designer, principal contractor, key subcontractors), management structure, and lines of responsibility for health and safety. This section establishes who is in charge and how decisions get made.

Communication and Coordination Arrangements

How health and safety information will be communicated between all parties on site. This includes: site induction arrangements, toolbox talks, coordination meetings, how subcontractors will be briefed, how design changes will be communicated, and how workers can raise concerns. On multi-contractor projects, coordination between different trades working simultaneously is critical.

Management of Significant Site Risks

The specific risks identified for this project and the control measures that will be applied. This must be project-specific — not a generic list. It should address risks arising from the site itself (ground conditions, existing services, contamination, adjacent operations), risks arising from the work (working at height, excavations, lifting operations, hot works), and risks arising from the environment (traffic, public access, noise restrictions).

Schedule 3 High-Risk Activities

Where the work includes any activities listed in Schedule 3 of CDM 2015, the CPP must include specific measures for managing them. These are the categories of work that the regulations consider inherently high-risk. See Section 5a below for the full list.

Site Rules

Clear, enforceable rules that apply to everyone on site. These typically cover: PPE requirements, working hours, prohibited activities (drugs, alcohol, unauthorised access), permit-to-work requirements, housekeeping standards, reporting procedures for incidents and near-misses, and disciplinary procedures for non-compliance.

Welfare Arrangements

What welfare facilities will be provided and where. CDM 2015 Schedule 2 sets minimum standards: toilets, washing facilities, drinking water, changing rooms, rest facilities, and facilities for heating food. The CPP must describe the actual arrangements — not just state that they will be provided.

Fire and Emergency Procedures

Emergency procedures for fire, medical emergencies, structural collapse, chemical spills, and any other foreseeable emergency. Must include: alarm systems, evacuation routes and assembly points, emergency contacts (including nearest A&E), first aid provision, fire extinguisher locations, and arrangements for vulnerable workers or members of the public.

Arrangements for Monitoring, Review and Compliance

How the principal contractor will monitor that the CPP is being followed. This includes: site inspections regime, auditing arrangements, how non-compliance will be dealt with, review triggers and update procedures, and how lessons learned from incidents will be fed back into the plan.

Health and Safety File Arrangements

How information will be gathered during the project for inclusion in the Health and Safety File — the end-of-project document that records information relevant to future maintenance or construction work on the completed structure. The CPP should describe who is responsible for collecting this information and how it will be passed to the Principal Designer.

5a. Schedule 3 — High-Risk Activity Categories

Schedule 3 of CDM 2015 lists ten categories of work that the regulations consider particularly hazardous. Where any of these activities form part of the project, the CPP must include specific measures for managing them. These categories also determine whether a project is notifiable to the HSE under Regulation 6.

Work which puts workers at risk of burial under earthfalls, engulfment in swampland, or falling from a height where the risk is particularly aggravated by the nature of the work or processes used or by the environment at the place of work or site.
Work which puts workers at risk from chemical or biological substances constituting a particular danger to the safety or health of workers or involving a legal requirement for health monitoring.
Work with ionising radiation requiring the designation of controlled or supervised areas under the Ionising Radiations Regulations 2017.
Work near high voltage power lines.
Work exposing workers to the risk of drowning.
Work on wells, underground earthworks, and tunnels.
Work carried out by divers having a system of air supply.
Work carried out in a caisson with a compressed air atmosphere.
Work involving the use of explosives.
Work involving the assembly or dismantling of heavy prefabricated components.

Schedule 3 in practice

Most construction projects will involve at least one Schedule 3 activity — typically work at height (category 1) or work near underground services (which may engage categories 1 or 2). The CPP must specifically address each relevant category. Simply listing them is not sufficient: the plan must describe the actual control measures that will be applied. For example, if the project involves work at height, the CPP must describe the specific access equipment to be used, the edge protection arrangements, and the fall arrest measures — not just state that “working at height will be managed safely.”

6. Why Does It Matter?

The safety case

Construction remains the most dangerous industry sector in Great Britain. The CPP exists because experience shows that construction accidents are disproportionately caused by failures in planning and communication — not by workers making individual errors. When workers are not told about hazards, when there is no coordination between trades, when emergency procedures are unclear, and when site rules are not established or enforced, accidents happen. The CPP is the mechanism that addresses all of these planning failures before work begins.

The legal consequences

Failure to prepare an adequate CPP — or to have one in place at all — exposes both the contractor and the client to enforcement action:

Improvement notices — requiring the contractor to prepare or improve their CPP within a specified timeframe.
Prohibition notices — stopping work immediately until a compliant CPP is in place. This can shut down an entire site.
Criminal prosecution — CDM breaches are criminal offences. Fines are unlimited in the Crown Court. Individuals face up to 2 years' imprisonment.
Fee for Intervention — the HSE charges £129 per hour for investigating material breaches. Even an investigation that does not result in prosecution generates a significant bill.

The practical and commercial case

A well-prepared CPP is not just a compliance document — it is a practical management tool. It forces the contractor to think through the sequence of work, the interfaces between trades, the logistics of the site, and the specific risks before anyone sets foot on site. Projects with good CPPs run more smoothly, have fewer delays caused by safety incidents, and generate fewer disputes about who was responsible for what. In commercial terms, the CPP is insurance against the costs of poor planning: lost time injuries, HSE investigations, prohibition notices that shut down sites, and the reputational damage that follows a serious incident.

7. Common Mistakes

Not having a CPP at all on smaller projects

This is the most fundamental error. Since CDM 2015, every construction project requires a CPP — including simple domestic work. A one-page plan for a low-risk domestic project is compliant; having no plan at all is a breach.

Copying a generic template without making it project-specific

A CPP that describes a different project, contains sections marked "N/A" throughout, or uses boilerplate text that does not reflect the actual site conditions is not compliant. The HSE expects the CPP to describe this project, this site, these risks.

Producing the CPP after work has already started

The CPP must be in place BEFORE the construction phase begins. Preparing it after work has started is a breach of both Regulation 12(1) and Regulation 4(5)(a). Both the contractor and the client are exposed.

Treating it as a one-time document that is never updated

The CPP must be reviewed, updated, and revised throughout the project as conditions change. New subcontractors, design changes, unforeseen hazards, programme changes — all require the CPP to be updated. A CPP that was adequate at the start of a project may be dangerously out of date three months later.

Not making it accessible to workers on site

A CPP that is locked in the site office, stored only on a laptop, or written in language that workers cannot understand does not meet the requirement. Workers must be aware of the arrangements and rules that affect them. The CPP must be available on site in a form that is accessible.

Failing to address Schedule 3 activities specifically

Where the project involves any of the ten categories of high-risk work listed in Schedule 3, the CPP must include specific measures for managing them. Listing the categories without describing the actual control measures is not sufficient.

Confusing the CPP with RAMS

Risk Assessments and Method Statements (RAMS) are separate documents that address specific tasks or activities. The CPP is the overarching site management document that sets out the framework within which RAMS sit. The CPP references RAMS — it does not replace them, and they do not replace it.

8. How It Relates to Other Documents

The CPP sits at the centre of the CDM documentation chain. It receives information from the PCIP and feeds information into the Health and Safety File. Understanding these relationships prevents documents being substituted for one another or critical information being missed.

Document	Relationship to the CPP
Pre-Construction Information Pack (PCIP)	The PCIP is the primary input to the CPP. It describes what is already known about the site — hazards, constraints, existing conditions, surveys. The contractor uses this information to prepare the CPP. You cannot write a proper CPP without the PCIP.
Health and Safety File	The H&S File is the project’s closing document, recording information needed for future maintenance or construction. The CPP should describe how information will be collected during the project for inclusion in the H&S File. The CPP feeds into the H&S File.
F10 Notification	A separate HSE notification required when a project is notifiable. The F10 does not substitute for the CPP and vice versa. Both are required on notifiable projects.
RAMS	Risk Assessments and Method Statements are produced by contractors and subcontractors for specific tasks. The CPP is the overarching framework document; RAMS sit beneath it. The CPP should reference the RAMS regime but does not contain individual task-level RAMS.
Site Induction Record	The site induction is the mechanism by which the CPP’s arrangements and site rules are communicated to workers. The CPP should describe the induction process; the induction record demonstrates it has been carried out.
Designer Risk Register	Designers must provide information about significant residual design risks. This information feeds into the PCIP and then into the CPP. The contractor must demonstrate in the CPP how these design risks will be managed during construction.

9. A Real-World Example

A sole-trader electrician was engaged to rewire a 1970s semi-detached house. The homeowner was a domestic client, so under CDM 2015 Regulation 7, the electrician inherited the client's CDM duties — including the duty to have a CPP in place before starting work. The electrician had never heard of a Construction Phase Plan and assumed CDM regulations only applied to large building sites.

During the rewire, the electrician drilled through a wall to route new cabling and struck an asbestos insulating board (AIB) panel concealed behind plasterwork. The property, built in 1973, had never been surveyed for asbestos. The electrician stopped work and reported it, but by that point fibres had been released. A licensed asbestos removal contractor was called in. The removal, air testing, and reinstatement cost £4,200. The electrician lost three weeks of work on the project and had to arrange personal health surveillance.

Had the electrician prepared even a simple one-page CPP using the HSE CIS80 format, the process of completing it would have prompted the question: “Is there asbestos in this property?” For a 1970s house, the answer is almost always “assume yes until surveyed.” A basic asbestos awareness check or management survey before starting work would have identified the AIB panel. The cost of that survey: typically £150–£300 for a domestic property.

The CPP is not paperwork for its own sake. It is a structured process that forces you to ask the right questions before you start work — and on this project, the right question would have prevented a £4,200 problem, three weeks of lost income, and a potential health exposure.

10. Frequently Asked Questions

Do I need a CPP on small projects?▾

Yes. Since CDM 2015, every construction project requires a CPP — regardless of size, duration, or value. There is no minimum threshold. For a simple, low-risk project, the CPP may be as short as one or two pages, but it must exist. Proportionality affects the depth of the plan, not whether one is required.

Was there a CPP requirement before CDM 2015?▾

Under CDM 2007, Construction Phase Plans were only required on notifiable projects — those lasting more than 30 working days with 20 or more simultaneous workers, or exceeding 500 person-days. CDM 2015 extended the requirement to every construction project, regardless of size or duration. This was one of the most significant changes in the 2015 regulations.

Who produces the CPP on a single-contractor project?▾

The sole contractor. On single-contractor projects, there is no principal contractor appointment. CDM 2015 Regulation 15(5) places the duty to prepare the CPP on the contractor carrying out the work. On domestic projects, the contractor also inherits the client’s CDM duties under Regulation 7.

Does the client need to review and approve the CPP?▾

The client must be satisfied that a suitable CPP is in place before allowing work to start (Regulation 4(5)(a)). This does not mean the client must technically approve the plan’s content — but they must not allow work to begin without one. In practice, commercial clients should review the CPP to discharge this duty. On domestic projects, the duty transfers to the contractor.

Can I use a template CPP from a previous project?▾

You can use a template as a starting point, but the CPP must be project-specific. Every section must be completed to reflect the actual site, the actual risks, and the actual arrangements for this project. A CPP that describes a different project is not compliant, even if the work is similar. The HSE expects the plan to address this site, this team, these risks.

Does the CPP have to be kept on site?▾

The CPP must be accessible on site. HSE guidance is clear that a plan which cannot be referred to by workers or inspectors during the construction phase does not meet the requirement. It does not have to be a physical paper document — a digital copy accessible on site is acceptable — but it must be available, not stored remotely where it cannot be accessed.

What is the difference between a CPP and RAMS?▾

The CPP is the overarching site management document that describes how health and safety will be managed across the entire project. RAMS (Risk Assessments and Method Statements) are task-specific documents produced for individual activities. The CPP provides the framework; RAMS provide the detail for specific tasks. The CPP references RAMS but does not contain them, and RAMS do not replace the CPP.

Does the CPP need to be updated during the project?▾

Yes. CDM 2015 Regulation 12(5) requires the CPP to be reviewed, updated, and revised from time to time so that it continues to be sufficient to manage health and safety risks. Common triggers for update include: new subcontractors arriving on site, design changes, unforeseen hazards, incidents or near-misses, and programme changes that alter the sequencing of work.

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