The construction industry in the UK has undergone some of its biggest reforms in decades, particularly in response to the lessons of the Grenfell Tower tragedy. One of the most significant changes is the introduction of a new Principal Designer role within Building Regulations, as part of the Building Safety Act 2022.
As a chartered quantity surveyor based in the UK, I’ve noticed growing confusion around the Principal Designer role—particularly how it differs under the new Building Regulations (via the Building Safety Act 2022) versus the older CDM 2015 duties. My aim here is to clarify that shift, explain what clients should expect, and how we as QSs can navigate these responsibilities.
A skilled CDM Principal Designer helps keep projects compliant with the 2015 Construction (Design and Management) Regulations from the outset.
At Saunders CQS, our robust, systemic approach means documentation dovetails with procurement procedures, without creating extra red tape. With our deep industry experience, we take what can often feel like an operational headache and turn it into something straightforward and efficient.
Here’s how we do it in practice:
This proactive style has supported projects as diverse as regional airports, historic churches and care homes.
Since October 2023, the Building Safety Act has introduced a separate Principal Designer role, this time under the Building Regulations.
While the CDM Principal Designer focuses on health and safety risks during design, the new Building Regulations Principal Designer is legally responsible for ensuring the entire design complies with Building Regulations. This includes fire safety, structure, energy efficiency, accessibility, and more.
Key duties include:
Unlike CDM, which is enforced by the Health & Safety Executive, the Building Regulations Principal Designer role is overseen by the Building Safety Regulator.
For those with an eye for detail, here is a side-by-side comparison of the two differing Principal Designer roles and how they differ, at a glance:
| Aspect | CDM 2015 Principal Designer | Building Regulations Principal Designer |
| CDM Regulations 2015 | CDM Regulations 2015 | Building Safety Act 2022 / Building Regulations |
| Primary Focus | Health & safety during design and pre-construction | Full design compliance with Building Regulations |
| Project Trigger | Projects with more than one contractor | All projects requiring building control approval |
| Duties | Manage risks, coordinate designers, PCI, safety file | Ensure compliance, manage design, submit statements |
| Enforcement Body | Health & Safety Executive (HSE) | Building Safety Regulator |
| Competence Requirements | Knowledge of health & safety and design coordination | Technical knowledge of Building Regulations, compliance, and evidence of competence (skills, knowledge, experience, behaviours) |
The two roles can sometimes be carried out by the same individual or organisation—but only if they can demonstrate competence in both areas. This is where the QS perspective becomes vital.
On a recent townhouse conversion, we identified early that the client had assumed the CDM Principal Designer covered Building Regulations duties. By setting out both roles clearly in the tender documents, we:
That foresight avoided delays at Gateway 2 and gave the client confidence that both health & safety and building compliance obligations were fully met.
The new Building Regulations Principal Designer role is not just a rebranding of CDM—it’s a shift in accountability that changes how we design, procure, and deliver projects. At Saunders CQS, we bring the same proactive, practical approach that we apply under CDM to this new role: embedding compliance into the process, supporting clients, and ensuring that safety and quality are built in from day one.
For advice on appointing a Principal Designer under either CDM 2015 or the Building Safety Act, contact us today for a no-obligation consultation.
