CDM Regulations 2015: Dutyholder Guide, Templates & Compliance Tools

The Construction (Design and Management) Regulations 2015 — SI 2015/51 — are the primary health and safety framework for construction work in Great Britain. They came into force on 6 April 2015 and replace CDM 2007. (HSE L153, para 19) This guide explains what the regulations require, who must comply, and — uniquely — walks through a real project scenario to show exactly how each duty is triggered in sequence. Use the free template and decision tree below to put compliance into practice.

Northern Ireland note: CDM 2015 (SI 2015/51) applies in Great Britain only. Northern Ireland operates under the Construction (Design and Management) Regulations (NI) 2016, which came into force on 1 August 2016. The two regimes are broadly similar but are separate statutory instruments — do not apply GB guidance directly to NI projects without checking the NI-specific rules.

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What the CDM Regulations Are — and the Statutory Instrument Behind Them

The CDM Regulations are made as a UK Statutory Instrument. The citation is The Construction (Design and Management) Regulations 2015, SI 2015/51. They set out the legal duties that must be fulfilled before and during construction work on any project — from a single-trade domestic job to a major infrastructure scheme.

The regulations work by assigning specific duties to named dutyholders based on the size and complexity of a project. Every project — regardless of size — triggers some duties. Larger or more complex projects trigger additional ones.

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Who CDM 2015 Applies To: The Five Dutyholders Explained

CDM 2015 identifies five dutyholders. Their duties scale with project complexity.

Dutyholder	Who they are	When the role exists
Client	The person or organisation for whom the project is carried out	Every project
Designer	Any person who prepares or modifies a design for a structure	Every project with design work
Principal Designer (PD)	Designer appointed by the client to coordinate health and safety in the pre-construction phase	Projects involving more than one contractor
Principal Contractor (PC)	Contractor appointed by the client to control the construction phase	Projects involving more than one contractor
Contractor	Any person who carries out, manages or controls construction work	Every project

Domestic clients — individuals having work done on their own home that is not connected to a business — have a different position under CDM 2015. When a domestic client is working with a single contractor, that contractor is responsible for preparing the construction phase plan, organising the work, and working together with others to ensure health and safety. (HSE CIS80) When more than one contractor is involved, the principal contractor will normally take on the client duties as well as their own, unless the domestic client asks the principal designer to take on the client duties in a written agreement. (HSE, principal contractors page)

What the other dutyholders actually owe

This page concentrates on the principal contractor, but three other sets of duties shape what arrives on a contractor's desk:

• Clients and pre-construction information — the client must make arrangements for managing the project so work can be carried out without risks to health or safety, and must provide pre-construction information to every designer and contractor — the site's known hazards (asbestos surveys, existing services, ground conditions) that your RAMS and the construction phase plan are built on. (CDM 2015, reg 4)
• Designers — anyone preparing or modifying a design must apply the general principles of prevention to eliminate or reduce risks through design decisions, and provide information about residual design risks to those who need it. The hazards a designer cannot design out land in your method statement. (CDM 2015, reg 9)
• The principal designer — plans, manages, monitors and coordinates health and safety in the pre-construction phase (the PC's mirror image), and assists the client in providing pre-construction information. (CDM 2015, reg 11)
• The health and safety file — on projects with more than one contractor, the principal designer must prepare a file containing the information future maintenance, refurbishment or demolition work will need, kept and updated through the project and handed to the client at the end. Your as-built RAMS detail often feeds it. (CDM 2015, reg 12)

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The Principal Contractor: Appointment Trigger, Legal Duties and Competence Requirements

A principal contractor is appointed by the client to control the construction phase of any project involving more than one contractor. (HSE, principal contractors page)

What the law requires the PC to do

Under CDM 2015, reg 13(1), the principal contractor must plan, manage and monitor the construction phase and coordinate matters relating to health and safety during the construction phase to ensure that, so far as is reasonably practicable, construction work is carried out without risks to health or safety.

In practice, the HSE summarises the PC's duties as: (HSE, principal contractors page)

• Plan, manage, monitor and coordinate the entire construction phase
• Take account of the health and safety risks to everyone affected by the work, including members of the public, in planning and managing the measures needed to control them
• Liaise with the client and principal designer for the duration of the project to ensure that all risks are effectively managed
• Prepare a written construction phase plan before the construction phase begins, implement it, and then regularly review and revise it
• Consult and engage with workers about their health, safety and welfare
• Ensure suitable welfare facilities are provided from the start and maintained throughout
• Check that anyone they appoint has the skills, knowledge, experience and, where relevant, the organisational capability to carry out their work safely
• Ensure all workers have site-specific inductions and any further information and training they need
• Take steps to prevent unauthorised access to the site

Under reg 13(3), the principal contractor must also organise cooperation between contractors (including successive contractors on the same site), coordinate their implementation of applicable health and safety legal requirements, and ensure that employers and — where necessary for the protection of workers — self-employed persons apply the general principles of prevention consistently.

Under reg 13(4), the principal contractor must ensure that a suitable site induction is provided, that steps are taken to prevent access by unauthorised persons, and that welfare facilities complying with Schedule 2 are provided throughout the construction phase.

Competence requirements

Principal contractors must have the skills, knowledge, experience and, where relevant, organisational capability to carry out their work. (HSE, principal contractors page) The appointing party — the client — must verify this before making the appointment.

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Competence checklist: what appointing parties must verify

Before appointing any designer, principal designer, contractor or principal contractor, the appointing party must be satisfied on all four of the following qualities (HSE L153, para 7):

Quality	What to look for
Skills	Relevant technical ability for the specific tasks involved
Knowledge	Understanding of the applicable legal requirements and site hazards
Experience	Demonstrated track record on comparable projects
Organisational capability (organisations only)	Systems, resources and management structures capable of delivering the work safely

These qualities must be established before the appointment is made — not after work has started.

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The Construction Phase Plan: Required on Every Project (with Free Template)

This is the most commonly misunderstood requirement in CDM 2015. A construction phase plan is required for every construction project under CDM 2015 — not only large or notifiable projects. (HSE CIS80)

Under CDM 2015, reg 12(1), during the pre-construction phase, and before setting up a construction site, the principal contractor must draw up a construction phase plan, or make arrangements for a construction phase plan to be drawn up. On projects with a single contractor and a domestic client, the obligation to prepare the plan falls on that contractor. (HSE CIS80)

The plan does not need to be complex. HSE CIS80 states that for small-scale routine work — such as installing a kitchen, structural alterations, roofing work or a loft conversion — a simple plan before work starts is usually enough to show that you have thought about health and safety.

Under reg 12(4), throughout the project the principal contractor must ensure that the construction phase plan is appropriately reviewed, updated and revised so that it continues to be sufficient to ensure that construction work is carried out, so far as is reasonably practicable, without risks to health or safety.

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Free Construction Phase Plan Template (CDM 2015 — based on HSE CIS80)

Review and adapt this template to your specific site, task and contractors. It must be completed by a competent person before the construction phase begins.

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CONSTRUCTION PHASE PLAN (CDM 2015 — required for every construction project)

Your name / company: Client name and address: Contact details of architect or principal designer: What is the job / brief project description: Is there anything the client has made you aware of (services, asbestos, access restrictions):

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KEY DATES

Milestone	Date
Construction phase start
Planned completion
Services disconnection / reconnection
Key build stages (groundworks, structure, fitout)

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SITE MANAGEMENT ARRANGEMENTS

Item	Details
Person responsible for ensuring the job runs safely
How supervision will be provided
How workers will be kept updated (daily briefings, toolbox talks, etc.)
Site rules (access, PPE, working hours)

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WHO ELSE IS ON SITE

Name / Company	Trade	Contact details
Principal contractor
Other contractors / specialists
Labourers

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MAIN DANGERS AND CONTROLS

Hazard	Present on this site?	Control measures
Falls from height	Yes / No	Scaffolding, edge protection, secured ladders
Collapse of excavations	Yes / No	Shoring, barriers, covers
Collapse of structures	Yes / No	Propping by competent person before removal
Exposure to building dusts	Yes / No	Wet cutting, vacuum extraction, RPE
Exposure to asbestos	Yes / No	Refurbishment survey before work; communicate results
Electricity / buried services	Yes / No	Isolate before drilling; avoid with plant
Risks to public / client family	Yes / No	Secure site, net scaffolds, restrict access
Other site-specific hazards

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EMERGENCY PROCEDURES

Item	Details
Nearest A&E / emergency services route
First aider on site
Emergency contact number
Procedure in event of serious / imminent danger

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WELFARE PROVISIONS (reg 13(4) and Schedule 2)

Facility	Location / arrangements
Toilets
Washing facilities
Rest area / facilities
Drinking water

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This template is provided by ramsdocs to support CDM 2015 compliance. It is designed to reduce RAMS rework and is PC review-ready, but it must be reviewed and adapted to the specific site, task and contractors by a competent person before use. ramsdocs does not provide legal advice and this template does not constitute legal advice.

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When You Must Notify the HSE: The 500 Person-Days / 30 Working-Day Threshold

Not every project requires formal HSE notification — but those that exceed the threshold must be notified before the construction phase begins.

⚠ Notification threshold

If the job will last longer than 500 person-days OR 30 working days (with more than 20 people working at the same time), it will need to be notified to HSE. (HSE CIS80)

HSE CIS80 notes that a project exceeding these thresholds is likely to be too complex for the simple plan format used on smaller jobs.

Note that both limbs of the threshold must be read precisely:

• Limb 1: more than 500 person-days in total (e.g. 11 workers × 50 days = 550 person-days — over the threshold; exactly 500 would not trigger it)
• Limb 2: more than 30 working days, but only where more than 20 workers are working simultaneously on any of those days

Notification is made using the HSE's F10 form, which can be submitted online via the HSE website. The HSE principal contractors page references the F10 as the notification mechanism. Notification should be submitted before the construction phase begins on notifiable projects — appointing the principal contractor and principal designer as soon as practicable before the construction phase starts allows them enough time to plan and manage their respective phases. (HSE L153, para 8)

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The General Principles of Prevention: The Framework All Dutyholders Must Follow

CDM 2015 requires designers, principal designers, principal contractors and contractors to take account of the general principles of prevention in carrying out their duties. The full set is the nine principles in Schedule 1 of the Management of Health and Safety at Work Regulations 1999; HSE L153 summarises the thrust of them as:

(a) avoid risks where possible; (b) evaluate those risks that cannot be avoided; and (c) put in place proportionate measures that control them at source.

The remaining principles cover adapting the work to the individual, adapting to technical progress, replacing the dangerous with the less dangerous, coherent prevention policy, prioritising collective protective measures over individual ones, and instructing employees. (HSE L153, para 5; MHSWR 1999 Schedule 1)

Under CDM 2015, reg 13(2), the principal contractor must take into account the general principles of prevention when design, technical and organisational aspects are being decided in order to plan the various items or stages of work — and when estimating the period of time required to complete work or work stages.

Under reg 13(3), the PC must also ensure that employers and, where necessary, self-employed persons apply the general principles of prevention in a consistent manner.

These principles are not a one-off exercise. They inform how every dutyholder plans their work from the pre-construction stage through to completion.

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Worked Scenario: A Two-Contractor Loft Conversion — CDM Duties in Sequence

This scenario illustrates how CDM 2015 duties are triggered in sequence on a real project type. It is a teaching tool — adapt all documentation to your specific site, task and contractors.

Project: Domestic loft conversion — occupied family home, London. Structural engineer and architect involved in design. Main contractor carries out the structural frame and roofing. Separate electrical contractor installs new circuits. Estimated duration: 8 weeks (40 working days), maximum 6 workers on site at any one time.

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Step	What happens	CDM 2015 duty triggered	Who owns it
1. Client brief	Homeowner commissions the project	Client duties apply — but as a domestic client, duties pass to the contractors under CDM 2015	Domestic client / contractors
2. Two contractors involved	Main contractor + electrical contractor = more than one contractor	Appoint a principal contractor and a principal designer	Main contractor typically acts as PC; architect or structural engineer as PD
3. Check notification threshold	8 weeks × max 6 workers = 240 person-days. 40 working days but never more than 20 simultaneous workers. Neither limb is met.	No HSE notification required	Principal contractor / client
4. Pre-construction: design coordination	Architect prepares drawings; structural engineer specifies beam sizes	Principal designer coordinates health and safety information from designers; passes pre-construction information to the PC	Principal designer (reg 12(3))
5. Construction phase plan	Before any work begins on site	PC must draw up (or arrange for) a construction phase plan covering key dates, site management, welfare, hazards and controls	Principal contractor (reg 12(1))
6. Competence checks	PC appoints the electrical sub-contractor	PC must verify the electrician's skills, knowledge, experience and organisational capability before appointment	Principal contractor (L153, para 7)
7. Construction phase begins	Scaffolding erected; structural beam installed	PC plans, manages, monitors and coordinates the construction phase; applies general principles of prevention (reg 13(1)–(2))	Principal contractor
8. Site induction	Electrician arrives on site	PC ensures a suitable site-specific induction is provided to every worker	Principal contractor (reg 13(4)(a))
9. Welfare	Throughout the project	PC ensures welfare facilities (toilets, washing, rest) are in place from day one and maintained	Principal contractor (reg 13(4)(c))
10. Unauthorised access	Occupied home — children present	PC takes steps to prevent unauthorised persons accessing the construction area	Principal contractor (reg 13(4)(b))
11. Plan review	Electrical work begins in week 5 — additional hazards (live circuits)	PC reviews and updates the construction phase plan to reflect new risks	Principal contractor (reg 12(4))
12. Health and safety file	Project completes	Principal designer (or PC if PD appointment has concluded) passes the health and safety file to the client	Principal designer / PC (reg 12(10))

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Dutyholder Decision Tree: Which Role Applies to Your Project?

Use this table to identify which CDM 2015 roles and duties your project triggers.

Question	Yes	No
Is there more than one contractor on the project?	Appoint a Principal Contractor and a Principal Designer → proceed	Single contractor carries out contractor duties and (for domestic clients) prepares the CPP
Has the client appointed a principal contractor?	PC takes on construction phase control duties (reg 13)	If domestic client has not appointed, the contractor in control of the construction phase carries out the PC role
Will the project exceed 500 person-days in total?	Notify HSE before the construction phase begins	No notification required on this limb — check limb 2
Will the project exceed 30 working days with more than 20 workers simultaneously?	Notify HSE before the construction phase begins	No notification required on this limb — check limb 1
Is the client a domestic individual (not acting in a business capacity)?	Duties transfer to PC (and PD if written agreement made)	Standard client duties apply
Are designers involved in preparing or modifying designs?	Designer duties apply; PD coordinates if >1 contractor	Designer duties still apply to any single designer on any project

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How ramsdocs Helps You Produce and Manage CDM Documentation

ramsdocs is a document management platform that helps construction businesses create, store, version-control and share CDM documentation — including construction phase plans, RAMS, and site-specific health and safety records.

• Build construction phase plans using structured templates based on HSE CIS80 — designed to reduce RAMS rework and support PC review-ready documentation
• Store and version-control all CDM documents in one place, with audit trails showing who reviewed and approved each document and when
• Manage appointments — record principal contractor and principal designer appointments, and log competence checks against the four qualities required by L153
• Share documents with the team — distribute CPPs, site rules and induction packs directly to contractors and workers

ramsdocs is a documentation tool. It does not provide legal advice, act as a principal designer or principal contractor, or guarantee regulatory compliance. All documents produced must be reviewed and adapted to the specific site and task by a competent person.

Start your free trial → | Download the CPP template →

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Frequently Asked Questions

What are the CDM Regulations? The Construction (Design and Management) Regulations 2015 (SI 2015/51) are the statutory framework governing health and safety management in construction work in Great Britain. They came into force on 6 April 2015 and replace CDM 2007. (HSE L153, para 19)

Who do the CDM Regulations apply to? They apply to everyone involved in a construction project — clients, designers, principal designers, principal contractors and contractors. Domestic clients have a modified position, with many duties passing to the contractors they appoint.

What is a principal contractor and when must one be appointed? A principal contractor is appointed by the client to control the construction phase of any project involving more than one contractor. (HSE, principal contractors page) They must be appointed as soon as practicable and before the start of the construction phase. (HSE L153, para 8)

Is a construction phase plan always required? Yes. A construction phase plan is required for every construction project under CDM 2015 — not only large or notifiable projects. (HSE CIS80) On small domestic jobs with a single contractor, a simple written plan is sufficient.

When must I notify the HSE? When a project will last longer than 500 person-days or 30 working days (with more than 20 people working at the same time). (HSE CIS80) Notification is made using the HSE's F10 form before the construction phase begins.

What competence must I check before appointing a contractor or designer? You must establish that they have the skills, knowledge and experience to carry out the work safely, and — if they are an organisation — the organisational capability to do so. This must be established before making the appointment. (HSE L153, para 7)

How do CDM 2015 duties differ for domestic clients? Domestic clients are individuals having construction work done on their own home, not in connection with a business. For a domestic client, the contractor (or principal contractor where there is more than one contractor) takes on client duties in addition to their own. (HSE, principal contractors page; HSE CIS80)

What are the general principles of prevention? They are the nine principles in Schedule 1 of MHSWR 1999, summarised by HSE as: avoid risks where possible; evaluate those risks that cannot be avoided; and put in place proportionate measures that control them at source. CDM 2015 requires designers, principal designers, principal contractors and contractors to take account of these principles in carrying out their duties. (HSE L153, para 5; MHSWR 1999 Schedule 1)

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Disclaimer: The information on this page is provided for general guidance only. It does not constitute legal advice. All CDM documentation — including any templates downloaded from this page — must be reviewed and adapted to the specific site, task and contractors by a competent person before use. ramsdocs is a document management tool and does not act as a principal designer, principal contractor, or CDM consultant. Compliance with CDM 2015 remains the responsibility of the relevant dutyholder on each project.