Building Risk and Compliance Building Control

The Role of the CDM Principal Designer in Keeping Projects Safe

Fri 02/27/2026 - 11:25

Construction sites are inherently hazardous environments where the potential for accidents and incidents remains ever-present.

Article by:

Neil Fenn

CDM Operations Director

Need some advice?

Leave your details and we will get in touch.

I want to be contacted by an expert

In the UK construction industry, the Construction (Design and Management) Regulations 2015 (CDM 2015) established a critical role to address safety from the earliest stages of a project: the Principal Designer. This position represents a fundamental shift in how we approach construction safety, embedding risk management into the design process itself rather than treating it as an afterthought.

This role consolidates what was previously the CDM Coordinator function under CDM 2007, but with enhanced responsibilities and a more proactive mandate. The Principal Designer must possess both design knowledge and health and safety competence, a combination that ensures safety considerations are integrated into every design decision.

Under the CDM regulations the Principal Designer plays a crucial role in working with the designers, helping to identify and mitigate design risks during the pre-construction phase i.e. before construction work begins - ensuring that safety is considered and built into projects at the earliest possible point.

This approach, known as designing out, is central to the Principal Designer's role and is specifically linked to addressing potential hazards during the design phase, rather than expecting contractors to manage them later. The overall goal is to ensure that a project can be constructed, maintained and used safely throughout its entire lifecycle, although future alterations and eventual demolition should also be considered.

“Consider a prestigious office building with a large, ornate chandelier suspended in a multi-storey atrium. It's an impressive design feature, but how will it be maintained? Traditional approaches might require scaffolding, mobile elevated work platforms, or rope access, all of which introduce significant health and safety risks and ongoing costs.
“A CDM Principal Designer would challenge this design early on, asking: ‘How will this chandelier be cleaned, maintained, or replaced?’. By raising this question during the design stage, alternative solutions can be explored, such as incorporating a mechanical lowering system that allows the chandelier to be brought safely to ground level for maintenance. This simple design modification eliminates the need for working at height entirely, protecting both construction workers and future maintenance teams.
“This principle applies across all aspects of construction design, from accessibility of mechanical plant for servicing, to the positioning of glazing for safe cleaning, to the selection of materials that won't require hazardous maintenance procedures.”

Neil Fenn, Operations Director for our CDM Consultancy & Building Risk and Compliance teams

It is worth noting, though, that the CDM Principal Designer doesn't work in isolation. Their role involves bringing together all members of the design team - architects, structural engineers, MEP consultants and specialist designers - to ensure health and safety considerations are integrated into every design decision.

In taking this collaborative approach, the CDM Principal Designer ensures that:

Designers understand their CDM duties and how their design choices impact health and safety
Significant risks are identified early when they're more cost-effective to address
Pre-construction information is gathered and shared with those who need it
Design evolution is tracked so that safety considerations keep pace with design development

Another, often-overlooked aspect of the CDM Principal Designer's role is planning for what happens after construction is complete. Buildings need to be maintained, cleaned, repaired, and eventually modified or demolished, and each of these activities presents potential health and safety risks.

With the full lifecycle of a building being kept in mind during the design phase, the CDM Principal Designer helps ensure that maintenance access is safe and practical, building services can be serviced without undue risk, future modifications can be carried out safely and the eventual demolition or deconstruction is feasible, without creating unnecessary hazards.

This forward-thinking approach protects not just construction workers, but also facilities management teams, building occupants and future contractors for many years to come.

By getting CDM Principal Designers involved at an early stage, there are better outcomes for everyone involved, including safer construction sites, more maintainable buildings and projects that progress more smoothly because potential problems have been anticipated and resolved from the offset.

While the Principal Designer role is a legal requirement under CDM 2015 for projects involving more than one contractor, the value lies in the safety improvements that derive from this approach.

For clients, designers, and contractors, recognising and supporting the CDM Principal Designer's work is not merely a regulatory requirement, it’s an investment in protecting lives, preventing incidents, and delivering projects that exemplify best practice in construction safety management.

At SOCOTEC, our CDM Principal Designer team brings together extensive construction industry experience with specialist health and safety knowledge. We understand both the technical challenges of construction and the practical realities of delivering complex projects.

The CDM Principal Designer role represents a shift in how the construction industry approaches health and safety, moving away from reactive hazard management to proactive risk elimination through intelligent design. As an approach, it benefits everyone involved in a project, from the construction team to the end users, and contributes to the ongoing improvement of health and safety standards across the industry.