CDM compliance means meeting the legal requirements set out in the Construction (Design and Management) Regulations 2015 (SI 2015/51). These regulations apply to every construction project in Great Britain — regardless of size — and define how projects must be planned, managed, and coordinated to protect workers and the public.
If you're involved in a UK construction project as a client, designer, or contractor, CDM compliance is a legal obligation, not a recommendation. For a practical compliance checklist and step-by-step process, see our complete CDM compliance guide or generate a free compliance checklist for your project.
What CDM 2015 actually requires
CDM 2015 is built around a simple principle: health and safety risks should be managed throughout the entire project lifecycle, starting at the design stage rather than waiting until work reaches site.
The regulations require five things:
- Appoint the right people. On multi-contractor projects, the client must appoint a principal designer (for the pre-construction phase) and a principal contractor (for the construction phase) before work begins.
- Plan before you build. A construction phase plan must be prepared before the construction phase starts. This covers site rules, health and safety arrangements, and measures for managing high-risk work.
- Verify competence. Every person or organisation appointed to work on the project must have the skills, knowledge, experience, and organisational capability for the role (Regulation 8).
- Coordinate and communicate. Duty holders must cooperate and share information. The principal contractor must coordinate all contractors on site. Workers must be consulted about health and safety matters.
- Document and hand over. A health and safety file must be maintained and passed to the client at project completion.
For a detailed breakdown of principal contractor duties and a subcontractor compliance checklist, see our CDM compliance guide.
Who has duties under CDM?
CDM 2015 assigns responsibilities to five duty holder roles. On small projects with a single contractor, one person may wear multiple hats. On larger projects, each role is distinct.
| Duty Holder | Key Responsibility | When |
|---|---|---|
| Client | Appoint competent people, provide pre-construction info, ensure adequate time and resources | Before and throughout |
| Principal designer | Plan, manage, and coordinate H&S in the pre-construction phase; identify and control design risks | Pre-construction |
| Principal contractor | Plan, manage, monitor, and coordinate H&S during construction; prepare the construction phase plan | Construction |
| Designer | Eliminate or reduce foreseeable risks through design decisions | Design |
| Contractor | Plan, manage, and monitor own work; cooperate with principal contractor | Construction |
Workers also have duties: they must take care of their own health and safety, cooperate with their employer, and report anything they believe is dangerous.
On projects with only one contractor: The contractor takes on the duties of both contractor and principal contractor. The client still has duties but does not need to appoint separate principal designer or principal contractor roles.
What happens if you don't comply
CDM 2015 is enforced by the Health and Safety Executive (HSE). Non-compliance is a criminal offence.
Enforcement actions include:
- Improvement notices — requiring you to fix a specific problem within a set timeframe
- Prohibition notices — stopping work immediately where there is a risk of serious personal injury
- Prosecution — for serious breaches or persistent non-compliance
Penalties for health and safety offences:
- Unlimited fines for organisations
- Fines and/or imprisonment for individuals (up to 2 years for most offences under the Health and Safety at Work etc. Act 1974)
- Manslaughter charges in cases where gross negligence causes death
The Sentencing Council guidelines link fines to the size and turnover of the offending organisation. For the most serious breaches, fines can reach six or seven figures depending on the size of the organisation and the level of culpability — and courts can go above the starting points.
Beyond criminal penalties, non-compliance can lead to:
- Civil claims from injured workers
- Contract termination by clients who require CDM compliance as a condition
- Insurance invalidation if an insurer finds you were non-compliant at the time of an incident
- Reputational damage that affects future tender outcomes
CDM compliance in 2026: what's changing
CDM 2015 itself hasn't changed, but the regulatory environment around it is tightening.
The Building Safety Act 2022 introduced a new Building Safety Regulator and strengthened competence requirements for duty holders on higher-risk buildings. While primarily targeting residential buildings over 18 metres, the Act's emphasis on demonstrating competence — not just declaring it — is raising standards across all construction work.
For principal contractors, this means having documents on file isn't enough — you need to demonstrate that you're actively managing compliance, verifying subcontractor competence, and monitoring ongoing adherence.
Frequently asked questions
Is CDM a legal requirement?
Yes. CDM 2015 applies to all construction work in Great Britain. It is law, not guidance. Non-compliance is a criminal offence enforced by the HSE.
Does CDM apply to small projects?
Yes. There is no minimum project size. A single-contractor kitchen refurbishment is covered, as is a multi-billion pound infrastructure project. The duties scale with project complexity, but the regulations apply universally.
What does CDM compliance mean in practice?
CDM compliance means having the right people appointed, a construction phase plan in place before work starts, documented evidence of competence for everyone on the project, active coordination between duty holders, and ongoing monitoring throughout the construction phase. It is not a one-off paperwork exercise — it requires continuous management.
What happens if you don't follow CDM?
The HSE can issue improvement notices, prohibition notices (stopping work immediately), or prosecute. Fines are unlimited for organisations. Individuals can face fines and imprisonment. In fatal cases, gross negligence manslaughter charges may apply.
Sources
- The Construction (Design and Management) Regulations 2015 (SI 2015/51)
- HSE — CDM 2015 guidance
- Health and Safety at Work etc. Act 1974
- Building Safety Act 2022
- Sentencing Council — Health and safety offences guidelines
This guide is for informational purposes and does not constitute legal advice. For project-specific CDM compliance questions, consult a qualified health and safety professional.
Last reviewed: 11 March 2026