Construction & Property

Comply with CDM Regulations for construction projects

How to comply with the Construction (Design and Management) Regulations 2015 (CDM 2015). Covers duty holder responsibilities, when to appoint Principal Designer and Principal Contractor, notifiable project thresholds, and F10 notification requirements.

UK-wide
Guide summary

You must follow CDM 2015 rules for any construction work in Great Britain. Appoint a Principal Designer and Principal Contractor for projects with multiple contractors. Provide pre-construction information and ensure health and safety plans are in place. Fines can exceed £100,000 for non-compliance.

  • Appoint Principal Designer and Principal Contractor for multi-contractor projects
  • Provide pre-construction information to all designers and contractors
  • Ensure construction phase plan is ready before work begins
  • Prepare and maintain health and safety file for future users
  • CDM applies to all construction including small projects and maintenance
  • Domestic clients' duties transfer to their contractor
  • Fines exceed £100,000 for health and safety failures
  • HSE actively enforces CDM 2015 regulations
On this page
UK-wide

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If you commission, design, or carry out construction work in Great Britain, you must comply with the Construction (Design and Management) Regulations 2015 (CDM 2015). These regulations set out legal duties to manage health and safety throughout a construction project's lifecycle.

CDM 2015 applies to all construction projects, regardless of size or duration. This includes new builds, demolition, refurbishment, maintenance, and repairs. Even small projects like fitting a new kitchen or extending an office building fall under CDM 2015.

Non-compliance is a criminal offence. The Health and Safety Executive (HSE) actively enforces CDM 2015, and fines for duty holder failures regularly exceed GBP 100,000.

What counts as construction work

CDM 2015 defines 'construction work' broadly. Understanding what's covered is essential before you can identify your duties.

Key point: If you're unsure whether work counts as 'construction work', it probably does. The definition is deliberately broad to ensure health and safety is managed across all types of building activity.

CDM duty holders and their responsibilities

CDM 2015 identifies specific duty holders, each with distinct legal responsibilities. The same person or organisation can hold multiple roles - for example, a design-and-build contractor might be both Principal Designer and Principal Contractor.

Understanding your role is critical. You cannot delegate or contract out of your CDM duties - the legal responsibility remains with you.

When you must appoint Principal Designer and Principal Contractor

On projects involving more than one contractor, the client must appoint:

  • A Principal Designer to plan, manage, and monitor the pre-construction phase
  • A Principal Contractor to plan, manage, and monitor the construction phase

Critical: These appointments must be made in writing before the relevant phase begins. If the client fails to make these appointments, they automatically assume all Principal Designer and Principal Contractor duties themselves.

The 'more than one contractor' test includes contractors working at different times, not just simultaneously. If your project involves an electrician, a plumber, and a builder working at different stages, you need Principal Designer and Principal Contractor appointments.

Separate Building Regulations roles: since 1 October 2023 there are also Building Regulations principal designer and principal contractor roles under Part 2A of the Building Regulations 2010 (inserted by SI 2023/911). These apply to all building work in England that is subject to building regulations and involves more than one contractor - not just higher-risk buildings. They are legally separate appointments from the CDM roles, with different competence criteria. The same firm can hold both, but an England client with more than one contractor on building-regs work must make both sets of appointments explicitly.

Domestic clients

If you're a domestic client (commissioning work on your own home, not for business purposes), your duties transfer automatically to the contractor (for single-contractor projects) or the principal contractor (for multi-contractor projects). You don't need to make formal appointments, but you should still choose competent contractors.

Pre-construction information requirements

Before construction begins, clients must provide relevant information to designers and contractors. This helps them plan work safely and identify risks early.

Practical tip: Start gathering pre-construction information early. Common sources include:

  • Existing building drawings and surveys
  • Asbestos surveys (mandatory for pre-2000 buildings)
  • Ground investigation reports
  • Utility company records for underground services
  • Previous health and safety files from earlier construction work

The earlier you provide this information to your design team and contractors, the better they can plan to eliminate or control risks.

When you must notify HSE

Certain construction projects must be notified to the Health and Safety Executive (HSE) before construction work begins. This is known as the 'F10 notification' after the form used.

Check if your project meets the notification thresholds:

Calculating thresholds

Working days: Count only days when construction work actually takes place. Weekends and bank holidays count only if work happens on those days. The project must last longer than 30 working days with more than 20 workers on site simultaneously.

Person-days example: the project must exceed 500 person-days.

  • 5 workers for 101 days = 505 person-days (notifiable)
  • 25 workers for 20 days = exactly 500 person-days (not notifiable - the project must exceed 500)
  • 10 workers for 40 days = 400 person-days (not notifiable on person-days alone)

When in doubt, notify. There is no penalty for notifying a project that turns out not to meet the thresholds. HSE prefers over-notification to under-notification.

How to submit F10 notification

The client has the legal duty to notify HSE. You may ask the Principal Designer or Principal Contractor to submit the notification on your behalf, but you remain legally responsible for ensuring it happens.

Submit your F10 notification online at hse.gov.uk/forms/notification/f10.htm. The online service provides instant confirmation.

Site display requirement: Once submitted, you must display the F10 notification (or HSE's acknowledgement) on site where workers can read it. This is a legal requirement throughout the construction phase.

Update the notification if significant details change - for example, if you appoint a different Principal Contractor or the project dates change substantially.

Construction phase plan requirements

The construction phase plan is a key CDM document. It must be prepared by the Principal Contractor before any construction work begins.

Work involving particular risks (Schedule 3)

CDM 2015 Schedule 3 identifies ten categories of high-risk construction work requiring specific risk control measures in the construction phase plan.

If your project involves any Schedule 3 work, the construction phase plan must include specific measures to address these risks. This is not optional - the Principal Contractor must ensure these measures are identified, communicated to all relevant parties, and implemented throughout the project.

Your duties as a client

If you're commissioning construction work, you are the 'client' under CDM 2015 and have significant legal duties. Here's what you must do:

  1. 1

    Make suitable management arrangements

    Ensure the project is set up so work can be done safely. This means allowing enough time and resources for health and safety to be managed throughout. Don't set unrealistic deadlines that force contractors to cut corners.

  2. 2

    Appoint competent duty holders

    Before appointing designers, Principal Designer, contractors, or Principal Contractor, check their skills, knowledge, and experience. Ask for evidence: qualifications, relevant project CVs, health and safety policies, professional memberships.

  3. 3

    Appoint Principal Designer (multi-contractor projects)

    If more than one contractor will work on the project, appoint a Principal Designer in writing as soon as you know there will be design work. They must have control over the pre-construction phase and sufficient resources to fulfil the role.

  4. 4

    Appoint Principal Contractor (multi-contractor projects)

    If more than one contractor will work on the project, appoint a Principal Contractor in writing before construction starts. They must be competent and given sufficient time and resources.

  5. 5

    Provide pre-construction information

    Gather and share all relevant information about the site with designers and contractors as soon as practicable. This includes asbestos surveys, structural drawings, ground conditions, underground services, and any known hazards.

  6. 6

    Ensure construction phase plan exists before construction starts

    Construction must not begin until there is a written construction phase plan in place. For multi-contractor projects, the Principal Contractor prepares this. For single-contractor projects, the contractor prepares it.

  7. 7

    Ensure welfare facilities are provided

    Workers must have access to toilets, washing facilities, drinking water, rest areas, and changing facilities. These must be in place before construction work begins.

  8. 8

    Notify HSE if project is notifiable

    If the project meets notification thresholds, submit F10 notification to HSE before construction begins. You can delegate the task but remain responsible for ensuring it happens.

  9. 9

    Ensure health and safety file is prepared

    At project completion, receive the health and safety file containing information needed for future construction work, cleaning, and maintenance. Keep it available and pass it to new owners if you sell the property.

Health and safety file requirements

The Principal Designer must prepare the health and safety file during the project and hand it to the client at completion. This document contains information needed for future construction work, maintenance, and cleaning.

Enforcement and penalties

CDM 2015 is enforced by the Health and Safety Executive (HSE). Breaching the regulations is a criminal offence under the Health and Safety at Work Act 1974.

Director and senior officer liability: Company directors, managers, and other senior officers can be prosecuted personally if a CDM offence was committed with their consent, connivance, or because of their neglect. You cannot hide behind the company.

Beyond criminal penalties, CDM failures can result in:

  • Civil claims: Injured workers or members of the public can sue for damages
  • Higher insurance premiums: Poor safety records increase costs
  • Reputational damage: HSE publishes prosecution details
  • Loss of contracts: Many clients require CDM compliance evidence before awarding work
Construction & Property Requirement

Construction industry-specific considerations

Construction businesses should be aware of additional sector-specific requirements:

  • Construction Skills Certification Scheme (CSCS): Most construction sites require workers to hold valid CSCS cards demonstrating competence
  • Site induction: All workers must receive a site-specific induction before starting work
  • Method statements: High-risk activities typically require written method statements (safe systems of work)
  • Considerate Constructors Scheme: Many projects require registration with CCS, which includes health and safety elements
  • Building Safety Act 2022: In England, for higher-risk buildings (at least 18 metres or at least 7 storeys AND containing at least 2 residential units, or a care home or hospital during design and construction), additional 'gateway' requirements apply during design and construction
  • Building Regulations dutyholder regime: Separately from CDM, all building work in England subject to building regulations with more than one contractor requires Building Regulations principal designer and principal contractor appointments (Building Regulations 2010 Part 2A, SI 2023/911) - this applies to ordinary building work, not just higher-risk buildings

Principal Contractors should ensure subcontractors understand these requirements and include them in site rules.

Common CDM compliance mistakes

Avoid these frequent errors that lead to enforcement action:

No written appointments: Principal Designer and Principal Contractor must be appointed in writing. Verbal agreements are not sufficient.

Appointing incompetent duty holders: 'Competence' means skills, knowledge, training, and experience appropriate to the task. Simply appointing someone cheap or available is not enough.

Failing to notify when required: Calculate person-days at project start. "I didn't realise it was notifiable" is not a defence.

Starting work before construction phase plan exists: Construction must not begin until there is a written plan in place, however simple the project.

Generic construction phase plans: A template document with the project name filled in is not acceptable. The plan must address specific risks of this project, on this site.

No pre-construction information: Clients must provide information about the site. "We didn't know" is not acceptable when information was obtainable.

Treating CDM as paperwork: CDM is about actually managing risks, not generating documents. Plans should be working documents used on site, not files gathering dust.