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The Construction (Design and Management) Regulations 2015 — commonly known as CDM 2015 — are the primary regulatory framework governing health, safety and welfare on UK construction projects. They came into force on 6 April 2015, replacing CDM 2007, and apply to virtually every construction project in the country.

For a construction project manager, CDM 2015 isn’t just a compliance box to tick. It’s the framework that defines who is responsible for what, when, and how. Getting it right protects your workers, your client and yourself. Getting it wrong can result in enforcement action, project shutdowns or worse.

Who does CDM 2015 apply to?

CDM 2015 applies to all construction work, though the extent of duties depends on whether a project is notifiable — meaning it will last more than 30 working days with more than 20 workers working simultaneously, or exceed 500 person-days of construction work. Notifiable projects require an F10 notification to the HSE and the appointment of a Principal Designer and Principal Contractor.

Even for non-notifiable projects, CDM 2015 still imposes duties on clients, designers and contractors. The scale of compliance requirements simply increases with the scale and complexity of the project.

The key duty holders

The Client has overarching duties, including ensuring suitable arrangements are in place for managing the project and that sufficient time and resources are allocated. On most commercial projects, the client appoints a project manager or client representative to discharge these duties.

The Principal Designer is responsible for planning, managing, monitoring and coordinating the pre-construction phase. They must ensure all designers cooperate with each other and that health and safety is considered throughout the design process. This role is often misunderstood — it is not simply about design, but about coordinating health and safety across the entire pre-construction phase.

The Principal Contractor takes over from the Principal Designer once construction begins. They plan, manage and monitor the construction phase, including producing and maintaining the Construction Phase Plan and ensuring all contractors cooperate with each other.

The three key documents

Three documents sit at the heart of CDM 2015 compliance. The Pre-Construction Information is compiled by the Principal Designer and provided to all designers and contractors before construction begins. The Construction Phase Plan is prepared by the Principal Contractor before construction starts and updated throughout the project. The Health and Safety File is compiled throughout the project and handed to the client at completion — it records information needed for future maintenance, alteration or demolition.

Common failure points

In our experience, the most common CDM failures are not dramatic — they’re administrative. The F10 not submitted or not updated. The Construction Phase Plan accepted but never reviewed. RAMS signed off but never checked against the actual work being done. Site inductions completed but records not kept.

The solution is a systematic approach to compliance checks — not a last-minute scramble before an audit. Monthly CDM site checks, a running action log and a habit of documenting everything are the habits that keep projects compliant and project managers protected.

The pre-start phase is where CDM compliance is either set up properly or set up to fail. By the time the first contractor mobilises on site, all of the foundational obligations should already be in place. In practice, they frequently aren’t — and the consequences play out throughout the construction phase.

This is the pre-start checklist we use on every project. It covers the key CDM obligations that must be confirmed before breaking ground on any notifiable construction project.

F10 & Appointments

• F10 notification submitted to HSE and up to date
• Principal Designer formally appointed in writing with agreed scope
• Principal Contractor formally appointed in writing
• All designers identified and competency confirmed
• Client representative / project manager named and contactable
• Contract Partners identified with competency evidence on file

SHE Plan & Programme

• Pre-Construction Information compiled and issued to all relevant parties
• Construction Phase SHE Plan received from Principal Contractor
• Construction Phase SHE Plan reviewed and accepted by the client representative
• RACI confirmed against the work programme and project phases
• Principal Contractor’s organisation chart in place and current
• Start and finish dates for the Construction Phase formally agreed
• Site induction presentation reviewed and approved

Meetings & Readiness

• Pre-start meeting held with minutes circulated and acknowledged
• Site mobilisation visit completed — no outstanding critical items
• Project progress meeting schedule agreed and in all diaries
• Client site visit schedule confirmed in the Construction Phase Plan

Why this matters

A project that starts with all of these items confirmed is a project with a strong CDM foundation. More importantly, it’s a project where all duty holders understand their responsibilities from day one.

The pre-start checklist isn’t bureaucracy. It’s the thing that prevents the 3am phone call six weeks into construction when an HSE inspector finds that the Construction Phase Plan was never formally accepted, or that two subcontractors were inducted without their competency records being checked. Document everything, keep records, and do the check properly before the project starts.

The F10 notification is one of the first CDM 2015 obligations for any notifiable construction project — and one of the most frequently mishandled. It’s not complicated, but it needs to be done correctly and at the right time.

What is the F10?

The F10 is the formal notification to the Health and Safety Executive (HSE) that a notifiable construction project is about to begin. Under CDM 2015, the client is responsible for ensuring the F10 is submitted. In practice, this duty is usually carried out by the project manager or client representative on the client’s behalf. Once submitted, the F10 notification must be displayed prominently on site for the duration of the project.

When is a project notifiable?

A project is notifiable if the construction phase will last longer than 30 working days with more than 20 workers working simultaneously at any point, or if it will exceed 500 person-days of construction work in total. If either threshold is met, the F10 must be submitted. If you’re unsure, the default position should be to notify — the consequences of failing to notify when required are significantly worse than notifying when it wasn’t strictly necessary.

When should it be submitted?

The F10 should be submitted as early as possible — ideally before the construction phase begins, and certainly before the Principal Contractor mobilises on site. If project details change significantly — for example, if the Principal Contractor changes or the project scope increases substantially — the F10 must be updated.

How to submit

The F10 is submitted online through the HSE website at hse.gov.uk/construction/cdm. You will need the project address and description, the client’s details, the Principal Designer’s details, the Principal Contractor’s details, and the planned start date and duration. The HSE does not charge for F10 submission. Once submitted, save a copy of the confirmation for the project SHE folder.

Common mistakes

The most common F10 mistakes we see: submitting after the construction phase has already started; failing to update the notification when the Principal Contractor changes; and not displaying the notification on site. All three can attract HSE enforcement action. None of them are difficult to avoid with a proper pre-start process in place.