Principal Designer PI Insurance UK 2026: Building Safety Act
General information — not advice. This guide explains how professional indemnity for Building Safety Act dutyholders generally works. It is not personalised advice or a recommendation, and it does not take account of your own circumstances. Policy wordings differ between insurers, so always check your own documents and speak to a broker before acting. Regulatory status is set out at the end of this guide.
What is principal designer PI insurance and why does the statutory role change it?
Principal designer PI is professional indemnity cover written to respond to liability arising from the statutory dutyholder role under the Building Safety Act 2022 and the Building Regulations, not just from ordinary design services. It matters because the role imposes duties that sit outside conventional design negligence — planning, managing and monitoring the design work of others, and signing compliance declarations. Some PI wordings exclude or sub-limit liability arising from statutory appointments unless specifically endorsed, so the role can fall outside the policy that was bought to cover it.
Key facts at a glance
- There are two separate principal designer roles and they are not the same appointment. The CDM 2015 principal designer manages health and safety in the pre-construction phase. The Building Regulations principal designer, introduced by the Building Safety Act 2022, manages Building Regulations compliance across the design. One firm may hold both, or neither.
- The Building Regulations principal designer duty applies to all building work, not only higher-risk buildings. The gateway regime and the more onerous regulatory oversight apply to HRBs, but the dutyholder duties themselves are far broader in scope.
- Underwriter commentary has been that BSA-specific exclusions are not generally being written into PI policies — but that is not the same as confirmation of cover. Some wordings exclude or sub-limit liability arising from statutory roles unless explicitly endorsed, and the difference has to be checked in your own policy rather than assumed from market commentary.
- Gateway 2 backlogs stalled several hundred higher-risk building projects during 2025. The Building Safety Regulator launched an Innovation Unit in August 2025, and now accepts staged applications for single-tower new HRBs, with reports that applications are beginning to turn around within the prescribed twelve-week period.
- An HSE report in June 2023 found only 18% of RIBA members were undertaking CDM principal designer roles. Reluctance among architects is opening the Building Regulations role to quantity surveyors, project managers and structural engineers — many of whom have never held a statutory dutyholder appointment before.
- Claims are expected to be triggered by three things: failure to obtain gateway approvals, failure to maintain golden thread information, and failure to demonstrate competence. All three are process failures rather than design errors, which is unfamiliar territory for a conventional PI claim.
- The Building Safety Levy takes effect on 1 October 2026 for residential schemes above 10 dwellings, with exemptions for affordable housing, care homes and hospitals. Further new Regulations came into force on 1 July 2026.
Most professional indemnity claims are about something you designed. Dutyholder claims are different: they are about something you were supposed to manage, coordinate or confirm. That distinction runs through everything in this guide, because it is the reason a policy written for design negligence may not sit comfortably over a statutory role.
The Building Safety Act created a regime in which named individuals and organisations carry defined, non-delegable duties. The client appoints dutyholders and must satisfy themselves of competence. The principal designer plans, manages and monitors the design work and coordinates matters relating to Building Regulations compliance. The principal contractor does the equivalent for construction. Each signs declarations. Each can be pursued by the others.
For a professional firm the practical consequence is that accepting a principal designer appointment adds a category of exposure that your PI renewal form may never have asked about. This guide is for architects, engineers, surveyors, project managers and multi-disciplinary practices taking or considering those appointments. It complements our architects' PI renewal guide, which covers the renewal process for architectural practices generally — this article deals specifically with the dutyholder role, whichever discipline holds it. Both sit within our professional indemnity insights hub.
How does the Insurability Framework apply to dutyholder PI?
Dutyholder PI is a new exposure in a market that already treats construction-related professional risk cautiously, and firms taking these roles are frequently doing so for the first time. That combination — unfamiliar liability, cautious market, inexperienced insured — is precisely where The Insurability Framework™ earns its keep.
The Miller & Partner Method
Four pillars applied to every dutyholder PI placement. The objective is to present a competent firm with a defined scope — because underwriters are pricing what you have agreed to do, and most of the risk in this class is created by appointment wording rather than by the work itself.
Underwriter Intelligence
Appetite for HRB and dutyholder work varies sharply between markets, and the questions differ: some focus on the proportion of higher-risk work, some on whether declarations are signed, some on competence frameworks. Knowing what each needs to see — and which will not write HRB exposure at all — determines whether a submission produces terms.
Difficult Risk Expertise
Firms taking a dutyholder role for the first time, practices with cladding or fire-safety history, small consultancies signing declarations they may not have capacity to verify, and anyone with a live notification are all placements the standard PI market handles awkwardly. These are ordinary submissions here.
Risk Assessment
The uninsured exposures here are contractual. Appointments that go further than statute requires. Warranties of compliance rather than duties of reasonable skill and care. Liability caps that do not match the PI limit. Novation without the dutyholder role being addressed. We read the appointment against the policy before either is signed.
Claims Advocacy
A dutyholder claim can arrive as a contribution claim from another dutyholder, a claim from the building owner, a Defective Premises Act claim from a homeowner, or regulatory action — sometimes simultaneously. We manage the insurer relationship across all of them and make sure the notification is made early enough to protect the claims-made position.
Where a practice has already been declined, or is carrying a live notification, the position is recoverable with the right presentation. Our guides on professional indemnity after a claim and insurance for businesses refused cover set out how that is rebuilt, and the Insurability Framework page explains the method in full.
Why are there two principal designer roles, and does your PI cover both?
Because they were created by different legislation for different purposes. The CDM 2015 principal designer manages health and safety risk in the pre-construction phase. The Building Regulations principal designer, created by the Building Safety Act, manages compliance with Building Regulations across the design. They can be held by the same firm or by different firms, and a PI policy or appointment that references only one does not automatically address the other.
This is the single most common confusion in the sector, and it produces real gaps in both appointments and insurance.
| Feature | CDM principal designer | Building Regulations principal designer |
|---|---|---|
| Source | Construction (Design and Management) Regulations 2015 | Building Safety Act 2022 and associated Building Regulations amendments |
| Focus | Health and safety risk during construction and in the completed structure | Compliance of the design with Building Regulations requirements |
| Regulator | Health and Safety Executive | Building Safety Regulator for HRBs; building control otherwise |
| Applies to | Projects with more than one contractor | All building work subject to Building Regulations, with enhanced regime for HRBs |
| Core duty | Plan, manage and monitor the pre-construction phase for health and safety | Plan, manage and monitor the design work and coordinate Building Regulations compliance |
| Declarations | No equivalent statutory compliance declaration | Declarations required at gateways confirming compliance of the design work |
| PI consequence | Long established; most wordings and appointments contemplate it | Newer; check whether the wording addresses statutory roles and whether the appointment is separate |
A firm can be the lead designer and neither principal designer. It can be the Building Regulations principal designer without being the CDM one. And on higher-risk buildings the client must satisfy themselves that whoever holds each role is competent for it. The appointment documents need to say clearly which role or roles are being accepted, because a generic reference to "principal designer" duties is now ambiguous.
Does your existing PI policy actually cover the statutory role?
Probably, but you need to confirm it rather than assume. Underwriter commentary has generally been that BSA-specific exclusions are not being written into PI policies. However, some wordings exclude or sub-limit liability arising from statutory appointments unless specifically endorsed, and most policies respond to negligence in the performance of professional services — which raises the question of whether managing and monitoring others' design work falls within your defined professional business.
Three questions to put to your broker in writing, and to get answered in writing:
- Does the definition of professional business or insured services encompass the Building Regulations principal designer role? If your business description says "architectural services" and you are now planning, managing and monitoring the design of others, that is worth confirming explicitly rather than inferring.
- Is there any exclusion or sub-limit applying to statutory or regulatory appointments? This is the specific wording feature to look for. Where it exists, an endorsement is usually available.
- Does the policy respond to the cost of defending regulatory action, as distinct from third-party civil claims? Building Safety Regulator enforcement is a different animal from a negligence claim, and defence costs alone can be material.
The wider structural point is that PI is claims-made. The policy that responds is the one in force when the claim is notified, not when the work was done. On building safety work — where defects can surface years after completion, and where the Defective Premises Act limitation periods were extended significantly by the Building Safety Act — that makes both the retroactive date and long-term continuity of cover far more important than usual. Our PI run-off cover guide deals with what happens when a practice closes, which on this exposure is a question that needs answering before it arises.
What happens to your liability if a gateway application fails?
Delay costs are the exposure, and they can be substantial. If a Gateway 2 application is rejected because the design information was incomplete or poorly presented, the project cannot start on site. The client's losses — finance costs, contractor standby, programme extension — may be pursued against whoever was responsible for the submission. Failure to obtain gateway approvals is one of the three most anticipated triggers for dutyholder PI claims.
The gateway structure sits at three points. Gateway 1 operates at planning. Gateway 2 applies before construction begins and requires Building Safety Regulator approval of the detailed design. Gateway 3 provides final assurance before occupation.
Gateway 2 is where the professional exposure concentrates, because it requires comprehensive design information demonstrating compliance with all Building Regulations, evidence that competent dutyholders have been appointed, a construction control plan and a change control plan. Published guidance is consistent that the most frequent cause of rejection is not technical failure but presentation — submissions that are hard to navigate, poorly indexed, or padded with irrelevant material, where the regulator cannot locate and verify key information without unnecessary cross-referencing.
That matters enormously for liability, because it means the risk is largely controllable. A rejection caused by a genuinely defective design is a design problem. A rejection caused by a disorganised submission is an administrative failure by whoever compiled it — and considerably harder to defend.
The position has improved. The Building Safety Regulator's Innovation Unit began accepting new HRB applications in August 2025, staged applications are now accepted for single-tower new HRBs following consultation with the Construction Leadership Council, and applications are reported to be turning around within the prescribed twelve-week period more consistently. But the exposure created by appointment wording during the backlog period remains live.
Why are compliance declarations a professional indemnity problem?
Because signing a statement that you have verified the work of others sits awkwardly with the foundation of professional indemnity, which responds to a failure to exercise reasonable skill and care — not to an inaccurate certification of fact. Commentary has specifically flagged that signing statements confirming verification of others' work, however caveated, appears to conflict with PI principles. The concern is sharpest for small and medium firms that may lack the capacity to verify what they are declaring.
This is the most under-appreciated exposure in the whole regime, and it deserves care rather than alarm.
The mechanism is straightforward. Professional indemnity is a negligence-based product. If you exercised reasonable skill and care, you are not liable, and the policy is not engaged. A declaration or certificate operates differently — it can create liability for the accuracy of a statement regardless of how carefully you reached it. If a declaration says compliance has been achieved and it later transpires it had not, the argument that you took reasonable care may not answer the claim, because the claim is that the statement was wrong rather than that you were careless.
What to do about it, practically:
- Do not sign wording that goes further than statute requires. The recurring professional advice is that any appointment for principal designer duties should not extend beyond what is written in the legislation. Where a client's draft adds warranties of compliance, push back.
- Base declarations on what you actually did. A statement framed around the steps taken and the information relied upon is materially safer than one asserting an outcome.
- Be realistic about capacity. If your firm does not have the resource to verify a discipline's work, either resource it, exclude it from your scope in writing, or decline the appointment. Accepting a role you cannot discharge is the underlying failure in most competence-based claims.
- Beware over-aggressive liability caps. Attempts to cap liability for statutory duties may result in the clause being invalidated, leaving you with the full exposure rather than the capped one you thought you had negotiated.
Should the principal designer role be a separate appointment?
Generally yes. A separate appointment offers greater clarity, certainty and protection for the consultant — provided the two liability caps are proportionate and the services are carefully defined. The alternative, bundling the role into the main design appointment, blurs the boundary between design liability and dutyholder liability, and creates difficulty on novation where design services transfer to a contractor but the statutory role arguably should not.
The decision turns on the project structure, the client's preferences, whether design services are likely to be novated, your PI provisions and limitations, and the need to manage conflicts of interest.
The arguments for separation:
- Distinct liability cap. The dutyholder role can carry its own cap, proportionate to the fee for that role rather than to the whole design commission.
- Cleaner novation. Design services are frequently novated to the contractor at some point. Whether the statutory role should follow is a separate question, and a separate appointment lets you answer it deliberately rather than by accident.
- Scope clarity. The services can be defined precisely against the statutory duties, which is the strongest protection available against scope creep into warranty territory.
- Conflict management. Where the principal designer must challenge the work of designers within the same organisation, a distinct appointment makes the role's independence visible.
The counter-argument is administrative: two appointments, two sets of terms, two caps to negotiate, and a client who may not want the complexity. Where the role stays bundled, the appointment must at minimum clearly reflect the distinct nature of the Building Regulations principal designer role and safeguard the practice accordingly.
Principal designer PI cover checker
Select the profile that best matches your practice to see the cover architecture we would normally build. For multi-disciplinary firms, our professional indemnity team can structure the whole programme on one submission.
Dutyholder insurability self-check
Tick every item you could evidence today. This is the list we work through before submitting a dutyholder PI risk — and it maps closely to what a client must satisfy themselves of when appointing you.
- Written confirmation from your insurer that the Building Regulations principal designer role falls within your insured professional business
- Policy checked for statutory-role exclusions or sub-limits, with an endorsement obtained where one exists
- Appointment wording does not exceed the statutory duty — no warranties or guarantees of Building Regulations compliance
- Which principal designer role you hold is stated explicitly — CDM, Building Regulations, or both
- Liability cap proportionate to the role's fee and consistent with your PI limit
- Documented competence framework for the individuals discharging the role, with CPD records
- Project-specific dutyholder matrix showing who is responsible for what, with oversight and challenge built in
- Golden thread information management protocol defining what is captured, by whom, and how it is handed over
- Design change control process that records and approves changes and updates the compliance position
- Declarations based on steps actually taken, not on assertions of outcome you cannot verify
- Novation position addressed — whether the statutory role transfers with the design services, decided in advance
- HRB and non-HRB fee split quantified for the last three years, ready for the PI proposal
Principal designer PI placement risk assessor
An indicative view of how your practice will be received at renewal, and what we would prioritise in the submission. This is general information only — not personalised advice, not a recommendation and not a quotation.
How does the golden thread create claims exposure?
By making information management a source of liability in its own right. The golden thread is the structured, accurate, accessible record of building safety information that must be created during design and construction and maintained throughout the building's life. Failure to maintain it is one of the three most anticipated triggers for dutyholder claims — meaning you can be liable for how you recorded and handed over information, independently of whether the design itself was sound.
This is a genuinely novel exposure for design professionals, and it is worth being precise about why.
Conventional PI claims allege that something was designed badly. Golden thread claims allege that the information about the building was incomplete, inaccurate, inaccessible or not handed over — so that a later duty-holder could not discharge their own obligations. The building may be perfectly safe; the failure is documentary. And because the golden thread must survive for the building's operational life, the exposure period is long.
Where the claims are likely to originate:
- Incomplete handover at Gateway 3. Final declarations from all dutyholders, evidence of compliance with each relevant regulation, and a complete record of design and construction changes are all required. Missing evidence is the most frequent cause of delay at this stage.
- Change control failures. A change control plan explaining how design changes are recorded and approved is a Gateway 2 requirement. Changes made and not documented break the thread and undermine the compliance case retrospectively.
- Handover to the accountable person. The information must be usable by whoever operates the building. A dump of unstructured files may technically transfer data while failing the duty.
- Later reliance. A future refurbishment, remediation or safety case will rely on the golden thread. If it is wrong, the loss may crystallise years after your involvement ended — engaging the claims-made structure and, potentially, your run-off cover.
Who can bring a claim against a principal designer?
Four categories, sometimes simultaneously: other dutyholders under contribution arrangements, the building owner or client under the appointment, future homeowners under the Defective Premises Act, and the Building Safety Regulator through regulatory action. That last route is not a civil claim at all, and defence costs alone can be material — which is why regulatory defence cover needs checking separately from third-party liability.
The multiplicity matters because it changes how a notification should be handled. A single underlying failure can generate several distinct proceedings on different timescales, with different standards of proof and different funding positions.
| Claimant | Route | What it looks like | PI position |
|---|---|---|---|
| Other dutyholders | Contribution between parties who share responsibility | Principal contractor or client seeking a share of a loss they have paid | Ordinarily within PI where based on your negligence; check contribution wording |
| Building owner / client | Breach of the appointment | Delay losses from gateway rejection, remedial costs, programme claims | Depends heavily on whether the appointment imposed duties beyond reasonable skill and care |
| Future homeowners | Defective Premises Act 1972, with limitation extended by the Building Safety Act | Dwellings not fit for habitation; claims arriving long after completion | Claims-made, so continuity and run-off become critical |
| Building Safety Regulator | Regulatory enforcement and prosecution | Enforcement notices, prosecution for failure to comply with duties | Fines are never insurable. Defence costs may be, if the policy provides regulatory cover |
| Leaseholders / RMC | Building Liability Orders and associated remedies | Remediation cost recovery where a corporate entity is unable to meet liabilities | Complex; specialist advice needed at notification stage |
The extension of limitation under the Defective Premises Act is the feature most likely to catch practices out commercially. It stretches the tail of the exposure far beyond what a professional firm's ordinary planning assumes, and it makes the decision to let PI lapse on retirement or closure considerably more consequential than it once was.
What drives the cost of principal designer PI in 2026?
Proportion of higher-risk building work above everything else, followed by the appointment terms you have accepted, competence evidence, claims history and limit purchased. The proposal stage matters more than it used to: a submission that addresses HRB and dutyholder exposure directly, with a clear narrative on how the firm discharges the role, is treated very differently from one that leaves underwriters to guess.
| Rating factor | Why it moves the premium | Mitigation |
|---|---|---|
| HRB fee proportion | The single largest factor. Higher-risk building exposure is rated separately from general design work. | Quantify it honestly across three years by discipline and sector, ready for the proposal. |
| Dutyholder roles accepted | Statutory roles carry duties beyond design negligence, and holding several concentrates liability. | State clearly which roles, on which projects, and whether separately appointed. |
| Appointment terms | Warranties of compliance and uncapped delay indemnities create exposure the policy may not follow. | Limit the appointment to the statutory duty; have it reviewed before signature. |
| Competence framework | Competence-based claims are among the three anticipated triggers, and clients must verify it anyway. | Documented competence and CPD arrangements per individual, not per practice. |
| Fire safety design protocols | Post-Grenfell the market examines fire-safety involvement more closely than any other discipline. | Written protocols and a clear statement of where specialist fire engineering input is obtained. |
| Golden thread arrangements | Information management failure is a claims trigger in its own right and is now asked about at renewal. | An information management protocol defining capture, structure, verification and handover. |
| Declaration practice | Signing statements verifying others' work sits uncomfortably with negligence-based cover. | Base declarations on steps taken; never assert outcomes you cannot verify. |
| Claims and circumstances | Any cladding or fire-safety history narrows an already limited panel considerably. | Disclose fully and evidence corrective action — see our PI after a claim guide. |
| Limit and aggregation basis | Each-and-every-claim versus aggregate matters enormously where one project can generate several claims. | Test the limit against project values and the number of parties who could claim, not fee income. |
| Retroactive date and continuity | Claims-made cover with a gap leaves earlier work unprotected, and this exposure has a long tail. | Map continuity across every prior year; avoid changing retroactive dates. |
| Sub-consultant management | Uninsured sub-consultants become your exposure when their work fails. | Verify their PI annually, retain certificates, and use back-to-back terms. |
| Discipline and routing | Architects, engineers and multi-disciplinary D&C firms are underwritten differently. | Route the submission to the right market for your discipline rather than a generic PI panel. |
Premium ranges in this class vary too widely to be useful without knowing limit, fee income and HRB proportion, so any figure quoted generically would mislead. What is consistent is the shape: dutyholder work on higher-risk buildings attracts materially higher rating than equivalent non-HRB design work, the spread between a well-presented and a poorly-presented submission is unusually wide, and firms that address HRB exposure head-on in the proposal are treated as a known quantity rather than an unknown one. For most practices the decisive variable is not the premium but whether the appointment terms have created liability the policy will not follow.
What are the principal designer's core statutory duties?
To plan, manage and monitor the design work during the design phase and coordinate matters relating to Building Regulations compliance, taking all reasonable steps to ensure that the design, if built, would comply. Alongside that sit duties to cooperate with other dutyholders, provide information, and — on higher-risk buildings — contribute to gateway applications and compliance declarations. The client must satisfy themselves that whoever holds the role is competent.
Planning, managing and monitoring
The verbs matter. The duty is not to design everything, nor to check every line, but to put arrangements in place so that Building Regulations compliance is addressed across the design work, to run those arrangements, and to monitor whether they are working. A practice that can evidence its arrangements has a real defence; one that treated the role as a title has very little.
Coordination and cooperation
Dutyholders must cooperate and share information. A project-specific dutyholder matrix showing who is responsible for what, and how oversight and challenge have been built into the design process, is both good practice and something the Building Safety Regulator expects to see in Gateway 2 submissions.
Competence
Dutyholders must be competent for the role, and the client must satisfy themselves of it before appointing. This is an organisational and individual test covering skills, knowledge, experience and behaviours. It is also the point at which declining an appointment becomes a legitimate and sometimes necessary risk control.
Gateways and declarations
On higher-risk buildings the design must pass Gateway 2 before construction begins, with the application demonstrating compliance and evidencing that competent dutyholders have been appointed, supported by a construction control plan and a change control plan. Gateway 3 requires final declarations from all dutyholders confirming the work was carried out competently and in accordance with the approved design.
Golden thread
Building safety information must be created, maintained and handed over in a structured and accessible form, and kept current throughout the building's life. Failure to follow the process can result in enforcement action or prosecution.
CDM duties where also held
Where the practice is also the CDM principal designer, the separate duties under the Construction (Design and Management) Regulations 2015 apply in parallel — planning, managing and monitoring the pre-construction phase for health and safety, and preparing the health and safety file.
Real dutyholder claims and what they cost
The three composites below reflect the exposure patterns this regime creates: one gateway rejection producing a delay claim, one appointment that converted a statutory duty into a warranty, and one golden thread failure surfacing years later. These are illustrative composites written for this guide — not real clients and not actual claims — and because the regime is young they are constructed from the anticipated claim triggers rather than from a mature claims record. The figures are indicative examples rather than settlements we have handled.
Case study 1 — Gateway 2 rejection and a delay claim
The situation: A multi-disciplinary practice was appointed Building Regulations principal designer on a 14-storey residential scheme. The Gateway 2 application was assembled under programme pressure and submitted with services information incomplete and the compliance evidence scattered across appendices without a contents map. The Building Safety Regulator rejected it. Resubmission took eleven weeks, and the contractor had already mobilised.
Claim type: Breach of appointment — delay losses.
Settlement: Contractor prolongation and standby £412,000. Development finance costs for the delay period £186,000. Additional consultant fees to reassemble the submission £48,000. The client alleged the submission fell below the standard of a competent principal designer. Liability was contested on the basis that the client's own late design changes contributed. Settled at £340,000 with a 45% contribution from the client, plus £71,000 defence costs, against a £2m limit.
Lessons: The rejection was not a design failure — the design was compliant. It was a presentation failure, which published guidance repeatedly identifies as the most common cause of rejection. A contents map linking each Building Regulations requirement to the document demonstrating compliance is a small piece of work that would have prevented the entire claim.
Renewal impact: Premium increased approximately 65%, with an HRB submission protocol required as a condition and the practice's contents-map procedure evidenced at renewal.
Case study 2 — An appointment that promised compliance
The situation: A structural engineering practice accepted the Building Regulations principal designer role on a student accommodation scheme. The client's standard appointment, which the practice signed without legal review, stated that the consultant "shall ensure the design complies with all applicable Building Regulations". After completion, a fire-stopping detail at a service penetration was found to be non-compliant. The detail had been produced by a specialist sub-contractor after novation.
Claim type: Breach of appointment — alleged failure to ensure compliance.
Settlement: Remedial works £275,000. The practice's defence was that it had exercised reasonable skill and care in planning, managing and monitoring, which is what the statute requires. The client's position was that the appointment imposed a stricter obligation — an absolute duty to ensure compliance — and that reasonable care was therefore beside the point. The insurer reserved its position on whether liability assumed under contract beyond the common law duty was covered. Settled at £190,000 after mediation, with the insurer contributing £140,000 and the practice bearing £50,000 plus £34,000 of its own costs.
Lessons: This is the central risk of the whole regime and it was created by a single word. "Ensure" is a warranty. "Take all reasonable steps" is the statutory duty. Professional indemnity responds to negligence, so an assumed contractual obligation stricter than the common law duty may fall outside cover. Any appointment for principal designer duties should not go further in wording than what is written in statute.
Renewal impact: Premium increased approximately 50%. The practice introduced mandatory legal review of all dutyholder appointments and now refuses "ensure compliance" wording as a matter of policy.
Case study 3 — Golden thread failure surfacing at remediation
The situation: Five years after completion, the accountable person for a higher-risk residential building commissioned remedial works to the external wall system. The golden thread information handed over at Gateway 3 recorded the specification but not a series of design changes made during construction to the cavity barrier arrangement. The remediation contractor priced and began work on the basis of the recorded specification, discovered the as-built condition differed, and the works had to be re-scoped.
Claim type: Negligent information management — claim by the building owner against the former principal designer.
Settlement: Abortive works and re-scoping £96,000. Extended scaffold hire and programme £58,000. Additional survey and design £37,000. The practice had ceased trading three years earlier but held run-off cover. Settled at £148,000, met by the run-off policy, with £29,000 defence costs.
Lessons: The building was safe and the original design was sound. The failure was documentary — changes made and not recorded, breaking the thread. Note that the claim arrived five years after completion and three years after the practice closed. Without run-off cover the former principals would have faced this personally, and the extension of Defective Premises Act limitation periods makes that scenario materially more likely than it once was.
Renewal impact: Not applicable — practice closed. Run-off cover continued, at a premium reflecting the notification.
How should you manage a principal designer PI notification?
Notify early and notify wide. PI is claims-made, so the trigger is not a claim but a circumstance which may give rise to one — and on dutyholder work that includes a gateway rejection, a regulatory query, or the discovery of an undocumented design change. Late notification is the most common reason cover is prejudiced. The eight steps below are the sequence we work to on behalf of clients.
- Notify a circumstance, not just a claim. A gateway rejection, an enforcement notice, a Building Safety Regulator information request, or a client letter alleging a failing all qualify. Notifying costs nothing; failing to notify within the policy period can cost everything.
- Do not admit liability or offer to put it right. The instinct to fix a compliance problem at your own cost is strong and it can prejudice the policy. Route it through your broker first.
- Establish which policy year responds. Identify when the work was done, when the circumstance became known, and what the retroactive date is on each relevant policy. On long-tail dutyholder work this is rarely obvious and it determines everything that follows.
- Assemble the appointment documents immediately. The appointment, any variations, the scope of services, the liability cap, and any novation. The wording will determine whether the claim is about negligence or about a warranty you gave — which is the single biggest factor in whether cover responds.
- Preserve the golden thread and your own records. Design registers, change control records, meeting minutes, coordination correspondence and the evidence behind any declaration you signed. These are the primary defence to a competence or process allegation.
- Separate the regulatory track from the civil track. Building Safety Regulator action runs independently, on its own timescale, and fines are never insurable even where defence costs may be. Answering the two inconsistently is a real risk.
- Map the other dutyholders early. Contribution claims run both ways. Identify who else held duties, what they did, and whether a contribution claim should be intimated by you rather than only against you.
- Do not let cover lapse while a notification is live. If the practice is closing or restructuring, arrange run-off before anything else — the case studies above show claims arriving years after completion, and the extended limitation periods make that the expected pattern rather than the exception.
Glossary of principal designer PI terms
- Accountable person
- The dutyholder responsible for an occupied higher-risk building, who relies on the golden thread handed over at completion to discharge their own duties.
- Building Safety Levy
- A charge taking effect on 1 October 2026 for residential schemes above 10 dwellings, with exemptions for affordable housing, care homes and hospitals.
- Building Safety Regulator (BSR)
- The regulator overseeing higher-risk buildings, determining gateway applications and taking enforcement action against dutyholders.
- Change control plan
- A Gateway 2 requirement explaining how design changes during construction will be recorded and approved. Failures here break the golden thread.
- Claims-made
- The basis on which PI operates: the policy responding is the one in force when the claim or circumstance is notified, not when the work was done.
- Competence
- The skills, knowledge, experience and behaviours a dutyholder must have. Clients must satisfy themselves of it before appointing, and it is an anticipated claims trigger.
- Construction control plan
- A Gateway 2 document setting out how the building work will be planned, managed and monitored.
- Defective Premises Act 1972
- Legislation giving a right of action where a dwelling is not fit for habitation. Limitation periods were extended significantly by the Building Safety Act, lengthening the exposure tail.
- Dutyholder
- A party with defined statutory duties under the Building Safety Act regime — client, principal designer, principal contractor, designers and contractors.
- Dutyholder matrix
- A project-specific document showing who is responsible for what and how oversight and challenge are built into the design process. Expected in Gateway 2 submissions.
- Gateway 1 / 2 / 3
- The three regulatory stop points for higher-risk buildings: at planning, before construction begins, and before occupation.
- Golden thread
- The structured, accurate and accessible record of building safety information created during design and construction and maintained throughout the building's life.
- Higher-risk building (HRB)
- A building within the enhanced regulatory regime by reference to height and use. HRB exposure is rated separately from general design work.
- Innovation Unit
- The Building Safety Regulator unit launched in August 2025 to accept new higher-risk building applications, introduced in response to Gateway 2 backlogs.
- Novation
- Transfer of a consultant's appointment from client to contractor. Whether the statutory dutyholder role should transfer with the design services needs deciding deliberately.
- Principal designer (Building Regulations)
- The dutyholder who plans, manages and monitors the design work and coordinates Building Regulations compliance. Created by the Building Safety Act 2022.
- Principal designer (CDM)
- The separate dutyholder under CDM 2015 responsible for health and safety in the pre-construction phase. A distinct role from the Building Regulations principal designer.
- Run-off cover
- PI maintained after a practice ceases trading, covering claims arising later from earlier work. Increasingly important given extended limitation periods.
Frequently asked questions about principal designer PI insurance
Probably, but confirm it in writing rather than assuming. Underwriter commentary has generally been that Building Safety Act specific exclusions are not being written into PI policies. However, some wordings exclude or sub-limit liability arising from statutory appointments unless specifically endorsed, and the definition of your insured professional business may not obviously encompass planning, managing and monitoring the design work of others. Ask your broker three questions: does the professional business definition cover the role, is there any statutory-appointment exclusion, and does the policy fund regulatory defence costs.
They are separate roles created by different legislation. The CDM 2015 principal designer manages health and safety risk during the pre-construction phase, regulated by the HSE. The Building Regulations principal designer, created by the Building Safety Act 2022, plans, manages and monitors the design work and coordinates Building Regulations compliance. One firm can hold both, either, or neither. Because a generic reference to "principal designer" is now ambiguous, appointments should state explicitly which role is being accepted.
No. The Building Regulations principal designer duty applies to building work generally, not just higher-risk buildings. What is confined to HRBs is the enhanced regulatory regime — the gateway approvals, the Building Safety Regulator's direct oversight, and the formal compliance declarations. So a practice doing no HRB work at all can still be a Building Regulations principal designer with statutory duties, which is a point frequently missed by firms who assume the regime is only about tall residential towers.
Anything that goes further than the statute. The recurring professional advice is that an appointment for principal designer duties should not extend beyond what is written in legislation. The specific danger is a clause requiring you to "ensure" compliance with Building Regulations — that is a warranty of outcome, whereas the statutory duty is to take all reasonable steps. Professional indemnity responds to negligence, so a contractual obligation stricter than the common law duty may fall outside cover entirely. Also be wary of over-aggressive liability caps, which may be invalidated and leave you with the full exposure.
Generally yes. A separate appointment offers greater clarity, certainty and protection for the consultant, provided the two liability caps are proportionate and the services are carefully defined. It allows a cap proportionate to the role's fee rather than the whole commission, keeps the novation question separate where design services transfer to a contractor, defines scope precisely against the statutory duties, and makes the role's independence visible where you must challenge colleagues' work. Where the client insists on bundling it, the appointment must at least clearly reflect the distinct nature of the role.
Potentially, and the exposure is delay rather than remedial cost. If a rejection stalls the project the client's losses — development finance, contractor prolongation, programme slippage — may be pursued against whoever was responsible for the submission. Failure to obtain gateway approvals is one of the three anticipated triggers for dutyholder claims. What makes this largely controllable is that the most frequent cause of rejection is presentation rather than technical failure: submissions that are hard to navigate, poorly indexed or padded with irrelevant material. A contents map linking each Building Regulations requirement to the document demonstrating compliance addresses most of it.
Because PI is negligence-based. It responds where you failed to exercise reasonable skill and care. A declaration operates differently — it can create liability for the accuracy of a statement regardless of how carefully you reached it. Commentary has specifically flagged that signing statements confirming you have verified the work of others, however caveated, appears to conflict with professional indemnity principles, and the concern is sharpest for small and medium firms lacking the capacity to verify what they declare. Base declarations on the steps you actually took rather than asserting outcomes you cannot verify.
Four routes, sometimes at once. Other dutyholders can seek contribution where they share responsibility for a loss. The building owner or client can claim under the appointment, typically for delay or remedial costs. Future homeowners can claim under the Defective Premises Act, whose limitation periods were extended significantly by the Building Safety Act. And the Building Safety Regulator can take regulatory action, which is not a civil claim at all — fines are never insurable, though defence costs may be if your policy provides regulatory cover.
By making information management a source of claims in its own right. Failure to maintain golden thread information is one of the anticipated claim triggers, meaning you can be liable for how you recorded and handed over information even where the design itself was sound. The typical scenario is a design change made during construction and not documented, discovered years later when a remediation contractor prices work from the recorded specification and finds the as-built condition differs. Because the thread must survive the building's operational life, the exposure period is unusually long.
Yes, and more urgently than before. PI is claims-made, so the policy that responds is the one in force when a claim is notified — if there is no policy, there is no cover, however long ago the work was done. The Building Safety Act extended Defective Premises Act limitation periods significantly, so claims arriving many years after completion are now the expected pattern rather than an outlier. Without run-off, former principals face those claims personally. Our PI run-off guide covers how it is arranged and what it costs.
Only with your eyes open. An HSE report in June 2023 found only 18% of RIBA members were undertaking CDM principal designer roles, and that reluctance among architects is opening the Building Regulations role to quantity surveyors, project managers and structural engineers. Before accepting, confirm your insured professional business covers a design-coordination statutory role — a QS or PM policy may not contemplate it. Document competence for the individuals involved, define scope tightly and exclude in writing anything outside your capability. Declining an appointment you cannot properly discharge is a legitimate risk control, not a commercial failure.
Look for a broker who asks to see the draft appointment before discussing the policy, who understands the difference between a statutory duty and a contractual warranty, and who has direct access to Lloyd's syndicates and specialist construction PI markets rather than a generic professional panel. Miller & Partner approaches every placement through the Insurability Framework — underwriter intelligence, difficult-risk expertise, risk assessment and claims advocacy — which is what allows first-time dutyholders, practices with fire-safety history and firms needing run-off against extended limitation periods to be placed on their facts. Start with our professional indemnity broker guide or the construction insights hub.
Important information
Regulatory status. Miller & Partner Limited is an Appointed Representative of Gauntlet Risk Management Ltd, which is authorised and regulated by the Financial Conduct Authority. Miller & Partner Limited is registered in England and Wales and trades from Vivian House, Roman Bridge Close, Mumbles, Swansea SA3 5BG.
This is general information, not advice. This guide is published for general information about how professional indemnity for Building Safety Act dutyholders works. It is not personalised advice, a personal recommendation, or an offer of cover, and it does not take account of the circumstances of any particular business. No liability is accepted for any action taken, or not taken, on the basis of this guide alone.
Cover, wordings and figures. Cover is subject to insurer acceptance, underwriting criteria, and the full terms, conditions, limits and exclusions of the policy issued. Wordings differ substantially between insurers, so always read your own policy documents. Any premium ranges, limits or claim figures shown are illustrative examples only and are not quotations or indications of price.
Case studies. The case studies in this guide are illustrative composites written for the purpose of explanation. They do not describe real clients or actual claims.
Regulation and legislation. References to legislation, regulators and official guidance reflect our understanding as at the date of publication and may change. Always work from the current published source rather than this guide.
Miller & Partner Limited, Vivian House, Roman Bridge Close, Mumbles, Swansea SA3 5BG. Telephone 01792 001350. FS Register FRN 1029698 — you can check this on the Financial Services Register at register.fca.org.uk.
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