BR Principal Designer vs CDM Principal Designer:What’s the Difference?

If you’re planning a UK construction project, you’ll quickly run into two similar-sounding roles. This guide explains BR Principal Designer vs CDM Principal Designer in clear, practical terms so you can appoint correctly, stay compliant, and avoid costly gaps between health & safety risk management and Building Regulations compliance.

Quick Summary

CDM Principal Designer (CDM PD): leads health & safety risk management in the pre-construction (design) phase under CDM 2015.

BR Principal Designer (Building Regulations Principal Designer / BR PD): leads Building Regulations compliance across the coordinated design under The Building Regulations 2010 (Part 2A).

One competent organisation can do both, but the aims, duties, and competence requirements differ - don’t assume one automatically covers the other.

Why the Roles Exist and Why They’re Different)

The names overlap because both roles orbit “design” and “coordination.” The CDM PD focuses on foreseeable health & safety (H&S) risks arising from design and pre-construction planning. The BR PD focuses on whether the design, if built as designed, would comply with the Building Regulations (structure, fire, services, energy, accessibility, etc.). In short:

CDM PD = H&S risk in design

BR PD = Regulatory compliance by design

Keeping this distinction front-of-mind will help your team manage deliverables, competence checks and programme timing.

Side-by-side: BR Principal Designer vs CDM Principal Designer

Legal basis	CDM Regulations 2015	Building Regulations 2010, Part 2A
Primary aim	Manage H&S risk in design/pre-construction	Lead Building Regulations compliance across the coordinated design
Core verb	Plan, manage, monitor & coordinate H&S	Plan, manage, monitor & coordinate compliance
Main counterpart	Principal Contractor (construction phase H&S)	Principal Contractor (planning/monitoring for compliance on site)
Trigger to appoint	More than one contractor	More than one contractor
Key outputs	Pre-construction information, design risk coordination, H&S File inputs	Coordinated, compliant design; clear information enabling compliant construction; end-of-appointment handover of arrangements
Competence lens	H&S in design (skills, knowledge, experience; organisational capability)	Building Regulations compliance leadership (SKEB and organisational capability; role-specific competence)
Can one do both?	—	Yes, if demonstrably competent for both roles

What the CDM Principal Designer actually does

A good CDM PD will:

Plan, manage, and monitor the pre-construction phase from an H&S perspective.

Coordinate designers so they eliminate risks where reasonably practicable and reduce/control residual risks.

Assemble and share pre-construction information so designers and contractors understand site and project constraints.

Liaise with the Principal Contractor so construction-phase plans reflect design risk decisions and residual hazards.

Drive design reviews that surface H&S implications early (access for maintenance, safe sequencing, temporary works needs, etc.).

Deliverables often include a design risk register, coordinated H&S design notes, and inputs to the Health & Safety File.

What the BR Principal Designer actually does

A competent BR PD will:

Plan, manage and monitor the design work so that if constructed as designed, it would comply with the Building Regulations (the “relevant requirements,” e.g., Parts A–S).

Coordinate all designers so their contributions add up to a coherent, compliant whole (no clashes or gaps between disciplines that could cause non-compliance).

Ensure cooperation and information flow to the Principal Contractor that is relevant to planning, managing and monitoring the works for compliance (e.g., tolerances, product dependencies, testing/commissioning requirements, inspections and records).

Provide a handover of arrangements at the end of appointment (explaining how PD duties were discharged and what information is relevant going forward).

Lead the “compliance by design” strategy, aligning specifications, details, schedules and evidence to the applicable parts of the Regulations.

Outputs typically include a compliance matrix, coordinated drawings/specs, product and system evidence, testing/inspection plans, and clear contractor information requirements.

Common Issues and How to Avoid Them

1) Assuming CDM PD = BR PD by default.
They’re separate roles. You can appoint one party to do both only if they truly meet both competence bars.

2) Late appointment.
Both roles work best early, when design decisions can actually change outcomes (fire strategy, structural strategy, façade systems, energy concepts, safe access/egress, etc.).

3) Vague scopes.
Write role descriptions that explicitly refer to either H&S risk management (CDM PD) or Building Regulations compliance leadership (BR PD). Avoid “coordination” as a catch-all.

4) Missing information pathways to site.
The BR PD must ensure the Principal Contractor has what they need to plan and monitor compliant construction: specifications, product data, acceptance criteria, inspection/test plans, and handover records.

5) Competence Checks.
For the BR PD, look beyond individual CVs. Check organisational capability (systems, QA, resources, technical leadership) and use structured frameworks (e.g., PAS-style criteria) for individuals.

Programme timing and appointments

CDM PD: appoint as early as possible where the project has or is likely to have more than one contractor. Early appointment allows proactive risk-in-design decisions (e.g., safe buildability, maintenance access, temporary works philosophy).

BR PD: on most projects, appoint before construction begins; for regulated/higher-risk routes ensure appointment is in place before control applications and key design gateways. Early involvement enables a compliance strategy that informs architectural, structural and MEP concept choices.

On domestic projects, duties can transfer if the client fails to appoint, but relying on defaults is risky and often leads to gaps. Make clear written appointments.

Competence and organisational capability

When comparing BR Principal Designer vs CDM Principal Designer, recognise that competence is context-specific:

For CDM PD: demonstrate skills, knowledge and experience in H&S risk management in design, plus the capability to coordinate multi-disciplinary designers against CDM duties.

For BR PD: demonstrate skills, knowledge, experience and behaviours in Building Regulations compliance leadership, plus organisational capability - including procedures for design coordination, technical governance, specification control, product substitution checks, change control, and evidence management.

For complex or higher-risk buildings, increase scrutiny: look for a designated competent individual leading the PD function, published procedures, and recent, relevant project experience with auditable outcomes.

Information Management

To make a combined or split appointment work, build an information model that separates and connects the streams:

Design Risk (CDM PD): risk registers, residual risk notes on drawings, temporary works implications, maintenance/cleaning strategies.

Compliance Evidence (BR PD): compliance matrix mapped to Parts A-S, test/assessment data for products/systems, fire strategy outputs, acoustic/thermal calculations, accessibility checks, commissioning/verification plans.

Coordination layer: decision logs, clash/risk/compliance reviews at each design stage, issue tracking with owners and deadlines, and a clear change-control process (including how substitutions will be assessed and approved).

This structure makes audits faster and reduces rework on site.

Can one party perform both roles?

Yes - many clients prefer a single point of leadership, often the lead designer or a multi-disciplinary design practice. However:

Declare the dual role explicitly in your appointments.

Evidence competence against both sets of duties.

Define outputs for each hat (CDM risk deliverables vs compliance deliverables).

Resource it: appoint a named competent individual to lead each function, even inside one organisation.

Record decisions: keep minutes, matrices and sign-offs that show how risks were addressed and how compliance was proven.

Practical Checklist

Use this when scoping BR principal designer vs CDM principal designer responsibilities:

Project overview: scope, procurement route, anticipated contractors, key risks, applicable parts of the Building Regulations.

Role separation: confirm whether one or two appointments; if one, list distinct deliverables for CDM PD and BR PD.

Competence: evidence of SKE/behaviours; organisational capability; similar project references; named lead; CVs and CPD.

Design reviews: schedule H&S design reviews (CDM) and compliance reviews (BR) with clear gateways and owners.

Information deliverables: risk registers, pre-construction information, compliance matrix, specifications, inspection & test plans, commissioning plans, records.

Change control: how will product/system changes be assessed for both risk and compliance before approval?

Handover: who compiles the H&S File inputs; who compiles compliance evidence and end-of-appointment BR PD arrangements.

Interfaces: Principal Contractor liaison expectations (meetings, logs, response times); how information reaches site teams in time to influence work.

Example Deliverables - BR Principal Designer vs CDM Principal Designer

From the CDM PD

Pre-construction information pack and updates.

Design risk reviews at concept, developed and technical stages.

Residual risk notes embedded in drawings/models.

Coordination logs and liaison notes to the Principal Contractor.

H&S File structure and content plan.

From the BR PD

Building Regulations compliance strategy and matrix (Parts A-S).

Coordinated drawings/specifications with compliance notes.

Evidence set: calculations, standards conformance, product data, assessments.

Information to the Principal Contractor: inspection/test requirements, tolerances, acceptance criteria, commissioning and verification plan.

End-of-appointment handover describing PD arrangements and key compliance information pathways.

FAQs: BR Principal Designer vs CDM Principal Designer

1) Is the BR Principal Designer the same as the CDM Principal Designer?
No. They are separate legal roles with different aims - compliance versus H&S risk. One party can hold both if they’re demonstrably competent for each.

2) Do we always need both?
If your project has, or is likely to have, more than one contractor, you must appoint a CDM PD and a BR PD. You can combine the appointments in one competent organisation.

3) Who should we appoint as CDM PD?
A designer with control over the pre-construction phase and proven H&S in design competence - often the lead designer, but not always.

4) Who should we appoint as BR PD?
A designer or design organisation with strong Building Regulations leadership, coordination capability across disciplines, and robust QA and evidence processes.

5) Can the Principal Contractor be either PD?
The PD must be a designer. The Principal Contractor is the counterpart on site; they are typically not the PD unless they also act as a designer with suitable competence.

6) What happens if we don’t appoint a BR PD?
The client may become responsible by default until a competent BR PD is appointed - this is risky and can stall approvals and site progress.

7) What competencies matter most for the BR PD?
Technical understanding of relevant Parts (A-S), design coordination skill, robust specification control, evidence collation, and the behaviours to challenge non-compliant solutions.

8) How do changes on site affect the BR PD’s role?
Any substitution or change must be re-checked for compliance. Your change-control procedure should route such changes back through PD oversight before approval.

9) How do the two PDs work together if different organisations hold the roles?
Set up joint reviews: CDM risk reviews and BR compliance reviews. Share logs and agree a single issue tracker with owners and response times. Align deliverables so risk decisions don’t undermine compliance, and compliance decisions don’t introduce unmanaged risks.

10) What documentation will help during audits or regulator interactions?
Appointment letters with scopes, competence evidence, meeting minutes, risk registers, compliance matrix, change-control records, test/inspection/commissioning evidence, and the BR PD end-of-appointment handover.

Conclusion - BR Principal Designer vs CDM Principal Designer

When you compare BR Principal Designer vs CDM Principal Designer, you’re really comparing compliance leadership with health & safety risk leadership - both anchored in design, both essential, and both best appointed early. Decide whether one organisation will carry out both rolls, verify and document competence for each, define deliverables clearly, and maintain disciplined information flows to the Principal Contractor and site teams. Do that, and you’ll de-risk design, speed approvals, and deliver a building that’s not only safe to build and operate, but compliant by design.

Contact

If you need a Principal Designer for Building Regulations who combines deep regulatory know-how with practical design coordination, get in touch. We’ll review your project, confirm competence transparently, and set up a clear plan to deliver compliance from day one.

To arrange a no-obligation consultation – please call 020 4534 3130.

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For more information on all aspects of the BR Principal Designer role see the collection of articles in our blog.

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