Principal Designer Building Regulations: The Complete Guide
If you’re delivering building work in England, you must understand the role of the Principal Designer under the Building Regulations. This complete guide explains who needs a Principal Designer, what the role covers, how competence is assessed, and how it differs from the CDM Principal Designer - so you can appoint correctly, manage risk, and evidence compliance. Throughout, we’ll use the key phrase principal designer building regulations naturally to help this page surface when you’re searching for practical, trustworthy answers.
What is the Building Regulations Principal Designer?
Under Part 2A of the Building Regulations 2010 (as amended), the Principal Designer (PD) is the designer appointed by the client to plan, manage and monitor the design work and coordinate design matters so the built outcome can comply with all relevant requirements of the Building Regulations. The legal definition and core duties sit in Regulations 11D (appointment) and 11M (additional duties of a principal designer).
In plain terms, the principal designer building regulations role is the design-side lynchpin for compliance: keeping design intent coordinated, making sure designs contain the information others need, and liaising with the Principal Contractor so what’s built can meet the regulations.
When must a Principal Designer be appointed?
A client must appoint in writing a designer with control over the design work as the Principal Designer whenever more than one contractor is, or is reasonably foreseeable to be, involved in a project. The timing depends on project type:
- Higher-risk building (HRB) work: appoint before submitting the building control application to the Regulator.
- All other projects: appoint before the construction phase begins.
If the appointment ends early, the client must promptly appoint a replacement; failure to appoint means the client themselves must fulfil the PD duties until someone else is appointed.
For domestic clients, if they don’t make the required appointments, the designer in control of the design phase automatically becomes the PD (and the contractor in control becomes the PC). There’s also a mechanism allowing the CDM PD to be treated as the Building Regulations PD by written certification.
What are the Principal Designer’s legal duties?
Regulation 11M sets out the PD’s headline obligations. The Principal Designer must:
- Plan, manage and monitor the design work during the design phase.
- Coordinate design matters to take all reasonable steps to ensure that, if built to the design, the work would comply with the relevant requirements.
- Ensure designers cooperate, design work is coordinated, and parties comply with their duties.
- Liaise with the Principal Contractor and share information relevant to planning, managing, monitoring and coordinating design and building work for compliance.
- Have regard to any compliance comments from the Principal Contractor.
- Assist the client, if requested, in providing information to others.
- When their appointment ends, within 28 days provide the client with a document explaining the arrangements they put in place to fulfil duties under 11M; a replacement PD must review those arrangements.
These duties make the principal designer building regulations role an active, continuous function - not a paperwork badge.
Client duties around the PD appointment (and everyone else)
Before letting any person start design or building work, the person engaging them (often the client) must take all reasonable steps to satisfy themselves about competence and - on HRBs - check for any serious sanction in the preceding five years. Clients must also be satisfied the PD can meet both the general competence requirement (11F) and the PD-specific competence requirement (11G).
Clients must make suitable arrangements for information and keep them under review, including identifying whether work is HRB and telling designers/contractors accordingly. Where there are joint clients, they can agree who is “the client” for duties; some duties (like sharing information) still apply to all.
Competence: what does “good enough” look like?
All persons carrying out design or building work must have the skills, knowledge, experience and behaviours (or, for organisations, organisational capability) to perform their work and fulfil their duties. That’s the general competence rule in Regulation 11F. Trainees can work only under adequate supervision and cannot be appointed as PD or PC.
For the Principal Designer, Regulation 11G requires the PD to have those same attributes specifically to fulfil PD duties. Where the PD is an organisation, it must designate an individual to manage the PD functions and must satisfy itself that person is appropriately competent.
While the Regulations are the binding law, many clients and dutyholders use PAS 8671:2022 as a competence benchmark. PAS 8671 sets thresholds across behavioural, legislative/regulatory, management of design work compliance, and technical domains, and suggests independent assessment/certification aligned to the PAS to verify individual competence. It also emphasises integrity (e.g., refusing non-compliant work) and the ability to challenge and coordinate effectively across the team.
Key point: PAS 8671 is not law; it’s a structured way to demonstrate the competence the law requires.
What information and evidence is needed at completion or early occupation?
When notifying completion to the relevant authority, the submission must include statements from the Principal Designer and Principal Contractor (or sole/lead equivalents) confirming they fulfilled their duties under Part 2A, along with contact details and appointment dates. Similar statements are required if any part of an applicable building will be occupied before completion (e.g., for buildings within the Fire Safety Order’s scope).
This locks in a clear audit trail: the client’s confirmations, plus PD/PC statements, will be scrutinised - so maintaining design compliance records and PD coordination logs throughout the project is essential.
How the Building Regulations PD differs from the CDM PD
Many projects already appoint a CDM Principal Designer. The regulations allow a client to treat the CDM PD as the Building Regulations PD by written certification, provided the person has the required control and competence. But the objectives differ:
- CDM PD: Plan, manage, monitor, and coordinate health & safety risk management during pre-construction.
- Building Regulations PD: Plan, manage, monitor, and coordinate design work for Building Regulations compliance (e.g., Parts A, B, L, O, etc.).
PAS 8671 underlines this difference: under the Building Safety Act-led regime, the PD’s primary objective is design work compliance, not H&S risk coordination.
A practical workflow for the Principal Designer Building Regulations
- Early strategy & appointment
Confirm project scope, foreseeability of multiple contractors, and appoint a principal designer building regulations at the correct time (HRB before application; otherwise before construction). - Competence checks
Verify PD and team competence against 11F/11G (and where helpful, reference PAS 8671 criteria or independent certification), documenting the steps taken. - Information arrangements
Set up and maintain client information flows (including HRB indicators) and ensure designers and contractors receive what they need when they need it. - Design planning
Establish a Design Compliance Plan: what standards apply, who is responsible for what, how design gateways/reviews will be run, and how comments are tracked to closure. (Aligns with PD’s 11M planning/management/monitoring duty.) - Coordination & challenge
Coordinate all designers; challenge insufficient evidence; consider the PC’s compliance comments and adjust design packages accordingly. - Liaison with the Principal Contractor
Share information critical to planning and coordinating buildability and compliance (e.g., tolerances, test regimes, installation conditions, O&M requirements). - Handover of arrangements (if PD changes)
If the PD role changes hands, produce and pass across the required arrangements document within 28 days; the incoming PD must review and adopt/update it. - Completion/occupation statements
Prepare the PD’s statement for completion or early occupation notifications; ensure the evidence base supports the declaration.
Common pitfalls - and how to avoid them
- Late appointment: Appointing after the construction phase starts (or, for HRBs, after application) undermines coordination and may breach 11D(3). Answer: Make PD appointment a pre-construction milestone and align with procurement.
- Treating PD as a title, not a function: Issuing an appointment letter without empowering the PD to control design work defeats the point. Answer: Appoint a designer with control and give them real authority (programme, gateways, information requirements).
- Inadequate competence checks: Skipping structured verification (especially on HRBs) risks non-compliance. Answer: Document checks against 11F/11G and consider PAS 8671-aligned assessment.
- Poor PD–PC liaison: Failing to share critical design information increases rework and compliance risk. Answer: Formalise information exchanges and record responses to PC compliance comments (as required by 11M(4)).
- Thin completion evidence: Unable to support PD declarations. Answer: Build an audit trail during design (assumptions, calculations, test standards, specs, approvals), ready for completion/occupation notices.
Minor work and exemptions
Where the project consists only of work described in Schedule 4, the client is not required to comply with Part 2A (the dutyholder and competence part). This is the “minor work” carve-out. Always check whether your scope genuinely fits Schedule 4 before relying on this.
FAQs: Principal Designer Building Regulations
Do all projects need a Principal Designer?
No. You must appoint a PD where more than one contractor is, or is likely to be, involved. If there’s only one contractor, no formal PD appointment is required - though the single designer may still carry coordination responsibilities.
When exactly do we appoint on an HRB?
Before submitting the building control application to the Regulator. For other projects, before construction begins.
Can our CDM Principal Designer double as the Building Regulations PD?
Yes, if they’re a designer with control over design work and the client certifies in writing that the CDM PD is treated as the Building Regulations PD, and if they meet the competence requirements.
What if a domestic client forgets to appoint?
If a domestic client doesn’t appoint, the designer in control of the design phase becomes the PD by default (and the contractor in control becomes the PC).
What does PD competence mean in practice?
Under 11G, the PD must have the skills, knowledge, experience and behaviours (or organisational capability) to fulfil PD duties. Many organisations use PAS 8671 to benchmark and evidence this.
Can an organisation be the PD?
Yes, but it must designate a competent individual to manage the PD functions, after taking reasonable steps to satisfy itself about that person’s competence.
What does the PD have to provide if they’re replaced mid-project?
Within 28 days of their appointment ending, the outgoing PD must give the client a document explaining the arrangements they put in place to fulfil 11M duties. The incoming PD must review those arrangements.
Do we need PD/PC declarations at completion?
Yes. Completion and certain early-occupation notifications must include signed statements from the PD and PC confirming they fulfilled Part 2A duties, plus contact and appointment details.
Is “minor work” exempt from these dutyholder rules?
Where the work is only what’s listed in Schedule 4, the client is not required to comply with Part 2A. Check scope carefully.
Conclusion - Principal Designer Building Regulations
The principal designer building regulations role is central to delivering compliant buildings under England’s post-Grenfell regime. Appoint early, appoint a designer with real control, verify competence (and be ready to show how), and empower the PD to coordinate design decisions and information. With a robust PD process - ideally aligned to a recognised competence framework such as PAS 8671 - you’ll reduce compliance risk, smooth your building control journey, and have the evidence you need at completion.
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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To discuss the Building Regulations Principal Designer role for your project please call 020 4534 3130.
For further information, please contact :
Sean Robinson
BSc (Hons) MCIOB MIFSM
Director, Head of Dept.
Building Safety
London