CDM 2015: Practical Compliance for Developers and Clients

26 October 2025 · 9 min read · Health & Safety

The Construction (Design and Management) Regulations 2015 represented a fundamental shift in how health and safety is managed on UK construction projects. Central to the regime is the repositioning of the client as the primary accountable party — the duty holder who sets the tone, appoints the team, and ensures that the framework operates. A decade on from implementation, CDM 2015 compliance remains inconsistent, with many clients still uncertain about what is required of them and what the consequences of failure look like.

Client Duties Under CDM 2015

Regulation 4 of CDM 2015 sets out the overarching duty on clients to make suitable arrangements for managing projects, including the allocation of sufficient time and resources. For commercial clients — which includes developers and anyone undertaking construction work in connection with a trade or business — these duties are comprehensive and non-delegable. The client can engage advisors to help, but legal accountability remains with the client throughout.

The key client duties are:

• Make suitable arrangements for managing the project (Regulation 4)
• Appoint a principal designer and principal contractor in writing (Regulation 5)
• Take reasonable steps to ensure duty holders have the necessary skills, knowledge, and experience (Regulation 8)
• Provide pre-construction information to designers and contractors (Regulation 4)
• Ensure the F10 notification is made to the HSE (Regulation 6)
• Ensure a construction phase plan is drawn up before construction begins (Regulation 12)
• Ensure the health and safety file is prepared, reviewed, and retained (Regulation 4)

"The client is the linchpin of CDM 2015. The Regulations place the client at the centre because the client controls the project — the decisions made at the earliest stages have the greatest impact on health and safety outcomes." — HSE Guidance L153, Managing Health and Safety in Construction

Principal Designer vs Principal Contractor

One of the most significant changes in CDM 2015 was the replacement of the CDM co-ordinator role with the principal designer (PD). The PD is responsible for planning, managing, and monitoring the pre-construction phase, coordinating health and safety during design, and ensuring that designers comply with their duties.

The principal contractor (PC) is responsible for planning, managing, and monitoring the construction phase, including the preparation of the construction phase plan, site security, site welfare, and consultation with workers. The PC role has remained broadly similar to the 2007 regime.

The critical decision for clients is who to appoint as PD. The Regulations require the PD to be a designer — someone who prepares or modifies designs, or arranges for others to do so. In practice, on many projects, the lead architect or lead consultant is the natural PD. But on design-and-build projects where the contractor controls the design, the contractor's in-house design team may be more appropriate. The appointment must be made in writing, and the client must be satisfied that the appointee has the necessary skills, knowledge, and experience (SKE).

F10 Notifications

A written F10 notification must be submitted to the HSE when a project meets either of two thresholds:

1. The project will be notifiable if it is expected to involve more than 30 working days with more than 20 workers simultaneously, or
2. The project exceeds 500 person-days of construction work

The notification must be made as soon as is practicable after the client knows enough about the project to complete the form. In practice, this means the notification is typically submitted after the principal designer and principal contractor are appointed but before construction work begins. If the project changes such that it crosses a threshold, a notification must be made at that point.

The F10 is not a permission — it is a notification. But failure to notify is a criminal offence, and the HSE uses notification data to target inspections. Non-compliance can also undermine insurance positions and complicate future property transactions.

Pre-Construction Information

Pre-construction information (PCI) is the information about the project and site that is relevant to health and safety. It must be provided to designers and contractors so they can discharge their duties. The client is responsible for providing PCI, typically with the PD's assistance in assembling and structuring it.

As a minimum, PCI should include:

• Site description and constraints (ground conditions, existing structures, services)
• Significant risks identified during pre-construction (asbestos, contaminated land, overhead lines)
• Relevant existing health and safety files from previous projects on the site
• The client's brief and any specific health and safety requirements
• Timetable for design and construction phases

PCI is a living document — it should be updated as more information becomes available and issued to each new appointee on the project.

Common Compliance Failures

From HSE enforcement data and our own project audits, the most common compliance failures are:

• Failure to appoint the PD and PC in writing before construction begins
• Inadequate or outdated PCI provided to tendering contractors
• Construction phase plan that is generic rather than project-specific
• Health and safety file not completed or not handed over at completion
• Client unaware of their duties, having delegated all responsibility to consultants without oversight

Practical Steps Now

1. Appoint a CDM advisor: if you do not have in-house CDM competence, appoint a CDM advisor to guide you through client duties — this is not the same as the PD and provides an additional layer of assurance
2. Make appointments early: appoint the PD and PC before any design or construction work starts, and ensure appointments are documented in writing
3. Prepare comprehensive PCI: invest time in assembling thorough pre-construction information — it reduces risk and demonstrates client diligence
4. Review the construction phase plan: the client's duty includes taking reasonable steps to ensure the CPP is in place — review it critically, do not simply accept it
5. Maintain the health and safety file: ensure the file is compiled throughout the project, not assembled retrospectively at completion
6. Keep records of all appointments and decisions: demonstrate compliance through a clear audit trail — the HSE will expect this if an incident occurs

Sources: Construction (Design and Management) Regulations 2015; HSE Guidance L153 (2024 revision); HSE, Construction Statistics in Great Britain 2024; RICS Guidance Note on CDM Compliance (2023); HSE F10 notification guidance; enforcement data from HSE prosecution database.