A multi-disciplinary health and safety consultancy in the south of England, with a chartered IOSH membership and a strong CDM advisory book, is appointed by a property developer as principal designer under CDM 2015 on a three-block residential redevelopment, two blocks above 18m and therefore within scope of the Building Safety Act 2022 higher-risk-building dutyholder regime. The consultancy's principal designer fee for the appointment is around £85,000 across pre-construction. Twenty-one months into the build, a worker on a downstream subcontract is seriously injured by a partial collapse of a temporary works element during façade installation. The HSE attends, an investigation begins and the Building Safety Regulator opens its own inquiry into compliance with the dutyholder regime. Eighteen months on, a civil action is filed by the worker for £1.6m; the client developer brings a contribution claim against the principal designer alleging that the design risk register failed to identify the temporary works interface risk and that the pre-construction information passed to the principal contractor was inadequate. The consultancy's PI policy — and specifically how it treats dutyholder appointments under CDM and the BSA — determines whether the firm has a year ahead defending the case from within insurance or facing a seven-figure exposure on its own balance sheet.
This article is the dutyholder companion to our pillar guide on H&S consultants' PI and the sibling to our cluster on construction H&S consultant PI. It deals specifically with the principal designer role — what it is under CDM 2015 and under the Building Safety Act 2022, who tends to hold it, what the PI policy is expected to cover, and where the wording, sub-limits and aggregates need to be examined carefully.
The principal designer role under CDM 2015
The Construction (Design and Management) Regulations 2015 introduced the principal designer as a CDM dutyholder, replacing the CDM coordinator that existed under the 2007 regulations. The appointment is required on any construction project involving more than one contractor (regulation 5(1)(a)), and the duties sit primarily in regulation 8 (competence) and regulation 11 (principal designer's duties).
Regulation 8 requires that anyone appointed to a role under CDM has the skills, knowledge, experience and (where they are an organisation) the organisational capability to fulfil the role. For a principal designer appointment this means demonstrable design-discipline understanding alongside H&S competence — which is part of why the role most often sits with the lead designer (architect or engineer) rather than with a freestanding H&S consultant, but where the design team does not include a member with sufficient H&S competence, the H&S consultant is often appointed instead.
Regulation 11 sets the substantive duties. The principal designer plans, manages and monitors the pre-construction phase. They coordinate health and safety matters during the pre-construction phase. They ensure that designers comply with their duties under regulation 9 (eliminating, reducing or controlling foreseeable risks at the design stage; providing information about residual risks). They prepare and provide the pre-construction information to every contractor and designer bidding for or appointed to the project. They liaise with the principal contractor during the construction phase, keeping them informed of relevant risks identified during ongoing design work. And they prepare the health and safety file for handover to the client at the end of the project — the document that runs with the building through its life.
The deliverables that crystallise these duties are the design risk register (the live document recording hazards identified at design stage, the controls applied, the residual risks passed on), the pre-construction information pack, ongoing design risk coordination during pre-construction, the handover to the principal contractor at the start of the construction phase, and the H&S file at completion. Each of these deliverables is the document the post-incident investigators and the contribution-claim solicitors will ask for.
The Building Safety Act 2022 dutyholder regime — parallel and distinct
The Building Safety Act 2022 introduced a separate dutyholder regime for higher-risk buildings (HRBs), defined as residential buildings 18m or above, or 7 storeys or more, with at least two dwellings. The regime is structured around the same dutyholder names as CDM — client, principal designer, principal contractor, designers, contractors — but the duties are different, the legal framework is different, and they run in parallel with the CDM regime, not in substitution.
The BSA principal designer's substantive duties are set under the secondary legislation made under the Act, notably the Building (Higher-Risk Buildings Procedures) (England) Regulations 2023 and the Building Regulations etc. (Amendment) (England) Regulations 2023. The role is concerned specifically with compliance with the Building Regulations — planning, managing and monitoring the design work, coordinating matters relating to the design work, and being able to demonstrate compliance with the relevant requirements through the gateway one, gateway two and gateway three process administered by the Building Safety Regulator within the HSE. The golden thread record-keeping duty sits across the role.
Two things follow that matter for PI. First, on an HRB project the consultancy is potentially holding two dutyholder appointments — CDM 2015 principal designer and BSA principal designer — which may be the same firm performing both functions or different firms performing each. The PI policy needs to deal with both, and underwriters typically ask the question explicitly at renewal. Second, the BSA regime imposes a substantially heavier compliance burden than CDM alone, with the BSR's gateway sign-off, the dutyholder declarations, the golden thread evidence, the change control process during construction and the as-built validation at gateway three. The work product is more extensive, the documentation trail is more demanding, and the claim exposure when something is alleged to have gone wrong is correspondingly larger.
Competence — the underwriting fulcrum
Underwriting principal designer exposure starts with competence. The consultant or firm taking the role needs to demonstrate, in evidence the insurer can review, that it has the skills, knowledge, experience and organisational capability to plan, manage and monitor the pre-construction phase on the projects it accepts. For a consultancy that is principally an H&S advisory firm rather than a design practice, the competence question typically focuses on the firm's track record with similar projects, the chartered status and CPD record of the lead principal designer individual, the firm's quality management system, whether the firm is OSHCR-registered, and what arrangements are in place for design discipline input where the firm itself does not employ architects or engineers.
For HRB BSA appointments the competence threshold is higher. The BSA principal designer is expected to demonstrate competence specifically in relation to higher-risk-building design and Building Regulations compliance — the design risk profile of HRBs (cladding, fire stopping, evacuation strategy, structural integrity for taller buildings) is genuinely different from low-rise commercial work. The competence framework set out in the Built Environment Competence Framework BSI publications (PAS 8671, PAS 8672, PAS 8673) is now standard reference material, and underwriters increasingly ask whether the firm's principal designer individuals can demonstrate compliance with the appropriate competence pathway.
What insurers ask about principal designer appointments
At renewal, insurers underwriting a consultancy with principal designer appointments will typically ask: how many active principal designer appointments does the firm hold; what is the value range of those projects; how many are HRBs within scope of the BSA; who is the named lead principal designer individual on each; what is that individual's chartered status and competence pathway; what design discipline input arrangements are in place; how is the design risk register maintained and shared; how is pre-construction information handover documented; what controls are in place to identify when an appointment crosses from non-HRB to HRB scope (which can happen as scheme proposals evolve); and what is the firm's track record on completed appointments.
The answers shape pricing, the sub-limits and aggregates that apply to the work, and the documentation the insurer asks for as a condition of cover. They also drive whether a notification is required at the point a new HRB appointment is taken on, which some policies require explicitly.
Sub-limits, aggregates and the BSA bucket
Most modern PI policies for consultancies with construction-facing work apply some form of aggregate cap on BSA-related claims. The structure varies — some policies aggregate "Building Safety Act 2022 related claims" against a single annual cap; some aggregate "claims arising from higher-risk buildings"; some aggregate "claims relating to dwellings within the scope of the Defective Premises Act 1972 as amended by section 135 of the Building Safety Act 2022"; some apply combined cladding-and-fire-safety aggregates. The wording detail matters because the precise scope of what falls in the aggregate bucket can shift the effective cover on a portfolio with mixed work.
A typical structure for a mid-sized consultancy might be a primary PI limit of £5m any one claim, with a BSA-related aggregate of £5m in the annual policy period — meaning that two seven-figure HRB claims notified in the same policy year could exhaust the BSA bucket and leave the firm uninsured for further BSA-related notifications until the next renewal. Larger firms may have layered programmes that purchase additional aggregate at higher attachment points specifically for BSA work.
Excesses on BSA-related and HRB-related claims are also commonly higher than the standard each-and-every excess — sometimes a fixed multiple, sometimes a percentage of the loss, sometimes a separate per-claim figure that engages where the loss is HRB-related.
The H&S consultant taking the role vs the architect or engineer doing so
Historically the CDM 2015 principal designer role was envisaged as sitting most naturally with the lead designer — the architect on building projects, the engineer on civil engineering or infrastructure projects — on the basis that the role's substantive duties (planning, managing and monitoring the pre-construction phase from a design coordination perspective) are most effective when held by the entity actually driving the design. In practice the role has split between two patterns: design-led practices holding the role as part of their architect or engineer appointment, and H&S consultancies holding the role as a freestanding professional appointment.
Each pattern has its own PI implications. Architects' PI and engineers' PI policies typically cover principal designer duties as part of the firm's professional activities, sometimes with explicit sub-limits or aggregate caps on BSA-related work and increasingly with explicit questions at renewal about the volume and nature of HRB principal designer appointments. H&S consultants' PI policies are similar in concept but the underwriting community is smaller and the schedule needs to be checked explicitly to confirm that principal designer duties are within the scheduled activities.
The H&S consultant holding the role as a freestanding appointment carries a particular underwriting weight: the design discipline element of the duty (coordinating the design risk register, liaising on regulation 9 designer duties) requires arrangements with the design team that the consultant is not themselves employing. Insurers ask how that interface is structured. Where the answer is robust — formal design risk register co-authored with the lead designer, regular design risk workshops minuted, clear allocation of regulation 9 responsibilities — the underwriting outcome is generally workable. Where the answer is loose, the underwriting response tightens.
What PI covers — and what it excludes
The civil liability that arises from a principal designer appointment is broadly within standard PI cover, subject to wording. A contribution claim from a client developer or principal contractor alleging that the principal designer's deliverables failed (design risk register inadequacies, pre-construction information omissions, inadequate handover to the principal contractor, defects in the H&S file) is the classic PI loss scenario.
What is excluded is criminal liability. Fines imposed on the principal designer under CDM 2015 regulation 11 breaches, under section 33 HSWA 1974, or under the BSA enforcement regime, are not insurable as a matter of UK public policy and are excluded from every standard PI policy. The same applies to fines imposed on the client developer or principal contractor — they are not paid by the principal designer's PI either, but they may give rise to civil contribution claims which would be.
Inquiry and investigation costs — the principal designer's legal costs of engaging with the BSR's investigation under the BSA, or with an HSE investigation under CDM 2015 — are commonly covered, subject to sub-limit. Where the appointment is on an HRB and the BSR's intervention is substantial (gateway non-compliance investigations, golden thread audit, post-incident inquiry), the sub-limit can be exhausted quickly and the firm needs to know in advance what the position is.
Specific exclusions to look for in the schedule: cladding-related work (commonly excluded or sub-limited even where the appointment is principal designer rather than façade designer); fire safety competence work on HRBs (sub-limited under the same BSA aggregate); pre-existing notifications and circumstances (excluded from the new policy year if not properly disclosed at renewal); work done before a specified retroactive date; and any obligation assumed exceeding reasonable skill and care (the appointment letter must not contain fitness-for-purpose language).
Run-off and the long tail
The principal designer's exposure has a long tail. The Defective Premises Act 1972, as amended by section 135 of the Building Safety Act 2022, gives 15 years for dwelling-related work completed on or after 28 June 2022 and 30 years for work completed before that date. The BSA dutyholder duties are themselves subject to enforcement that can reach back many years. For an H&S consultancy that has taken on principal designer appointments on residential schemes, the run-off decision on cessation needs to reflect that long tail — which often means run-off for substantially longer than the six-year contractual baseline, and at a multiple of the last working policy premium that reflects the residual exposure.
How Apex helps
Apex Insurance Brokers is an independent FCA-authorised insurance broker. We act for the consultancy under the FCA's Conduct of Business rules. Where a consultancy holds CDM 2015 principal designer appointments — and particularly where it also holds BSA principal designer appointments on higher-risk buildings — the PI placement decisions are materially more complex than for general H&S advisory work. We work with insurers across the market and place coverage for consultancies in this space regularly. The terms on which we act are in our Terms of Business; our handling of personal data is in our Privacy notice; the route to raising concerns is on our Complaints page. The health and safety consultants sector page is the place to start a renewal conversation, or contact us directly.
Frequently asked questions
Is the CDM principal designer the same as the BSA principal designer?
No. The CDM 2015 principal designer is a dutyholder under regulation 5 and regulation 11 of CDM, with duties focused on planning, managing and monitoring the pre-construction phase for health and safety. The BSA principal designer is a dutyholder under the Building (Higher-Risk Buildings Procedures) (England) Regulations 2023 and connected legislation, with duties focused on planning, managing and monitoring design work for compliance with the Building Regulations on higher-risk buildings. They share the name and frequently the same individual appointment, but they are legally distinct roles operating under different regimes and running in parallel on HRB projects.
Can a freestanding H&S consultancy hold the principal designer appointment?
Yes, and many do. The competence test under CDM regulation 8 requires the appointee to have the skills, knowledge, experience and organisational capability to fulfil the role; that test is met by H&S consultancies with appropriate competence and design discipline interface arrangements. For BSA HRB appointments the competence threshold is higher and the design coordination interface needs to be more robust, but H&S consultancies do hold BSA principal designer appointments — typically in arrangement with the lead designer for the design coordination element.
What is the design risk register and why does it matter?
The design risk register is the live document maintained by or under the principal designer's direction that records hazards identified during the design stage, the design decisions taken to eliminate, reduce or control them, and the residual risks that need to be passed to the principal contractor and downstream contractors. It is a deliverable that crystallises the principal designer's regulation 11 duties. After an incident on site, the design risk register is one of the first documents requested in HSE and BSR investigations and in any civil contribution claim — its quality and completeness are central to the principal designer's defence.
Are BSA-related claims aggregated under my PI?
Almost certainly yes. Most modern PI policies for construction-facing consultancies apply some form of annual aggregate cap on BSA-related claims — sometimes labelled "Building Safety Act 2022 related claims", sometimes "claims arising from higher-risk buildings", sometimes captured under a combined cladding-and-fire-safety bucket. The wording varies and the precise scope of what falls in the aggregate matters. The broker should walk through the specific BSA aggregate language in the policy and explain it explicitly at each renewal.
Does my PI cover defence costs for a Building Safety Regulator investigation?
It depends on wording. Most policies include defence costs for regulatory investigations within the PI policy or as a separate legal expenses extension, but sub-limits apply and the sub-limit can be exhausted on a substantial BSR intervention. Where the principal designer is responding to a gateway non-compliance investigation, a golden thread audit or a post-incident inquiry by the BSR, the legal costs can be substantial. The broker should confirm explicitly what cover is in place for BSR investigations as a distinct question from HSE CDM investigations.
Will my PI pay the fine if I am prosecuted under CDM 2015 or the BSA?
No. Criminal fines under CDM 2015, under HSWA 1974, or under the BSA enforcement regime, are not insurable under UK public policy and are excluded from every standard PI policy. What can be covered, subject to wording, is the legal costs of defending the prosecution. The structural civil exposure is the contribution claim from the client developer, principal contractor or other dutyholder for damages they have paid to an injured party, and that contribution claim is the principal designer's PI loss.
How long should I hold run-off for a consultancy that has taken on principal designer appointments?
Longer than the six-year contractual baseline. The Defective Premises Act 1972 as amended by section 135 of the Building Safety Act 2022 gives 15 years for dwelling-related work completed on or after 28 June 2022 and 30 years for work completed before. Principal designer appointments on residential schemes within scope of the DPA need run-off arrangements that reflect those periods, even where the cost is significant. The broker should model the run-off cost against the residual exposure as part of any cessation or sale planning.
Related guides
- The pillar — H&S consultants' PI insurance UK guide 2026
- Construction H&S consultant PI — the site adviser exposure
- Health and safety consultants sector page — speak to a broker
- All Apex PI sectors
About Apex Insurance Brokers
Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority, FCA firm reference 724952. Registered in England and Wales, Companies House 07014570. Trading address QCS, 53 Queen Charlotte Street, Bristol BS1 4HQ; registered office c/o Westcan, 5 Anglo Office Park, Bristol BS15 1NT. Email info@apexinsurancebrokers.co.uk, telephone 0117 325 0027. This guide is general information about Professional Indemnity Insurance for UK consultancies holding CDM and Building Safety Act principal designer appointments and is not advice tailored to any individual firm's circumstances. Last reviewed: May 2026.
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