Architects run-off · UK 2026
Run-off cover for UK architectural practices
Reviewed by Matthew Bartlett, Director, Apex Insurance Brokers Limited · Published 14 July 2026
Closing an architectural practice doesn't close its liability tail. ARB Standard 8 requires PII adequate to the tail; the Building Safety Act 2022 s.135 has extended that tail materially. This page sets out how run-off works for UK architects, what it costs, and what specialist broker input adds.
Why architects need run-off cover
UK PI insurance is claims-made. A claim made after policy expiry is not covered unless a run-off extension is in place. Architects face this tail exposure especially strongly:
- Long limitation period. Professional-negligence claims run six years from the breach date, plus discoverability. BSA 2022 s.135 extended this to 30 years for pre-June-2022 higher-risk-building work, 15 years going forward.
- ARB Standard 8. Requires PII adequate to the risk of the practice, and continues to apply to individual architects even after firm cessation.
- BSA higher-risk-building work. Anything above 18m or 7 storeys with residential creates a materially extended tail.
- Principal Designer role under BSA 2022. Formal role for higher-risk-building projects. Personal exposure attached.
- Historic acts as employee or partner elsewhere. Individual architect personal exposure follows the individual, not just the practice.
How run-off is structured
- Single-premium block. Pay upfront for a defined period (typically 6 years). Cover then continues on those terms without further premium payments.
- Annual renewable. Premium re-quoted each year until decision to close. More flexible but exposes the firm to hardening markets during the tail.
- Extended coverage for BSA work. Additional period beyond the base block for higher-risk-building projects.
- Individual personal cover. Retained beyond firm run-off where the individual architect has BSA-touching career exposure or specialist practice areas.
- Named-project extended cover. Specific extension for large individual projects beyond the standard block.
Sizing the run-off period
- Non-BSA residential-only work. Typically 6 years matches the standard limitation period.
- Commercial work. 6-12 years depending on project profiles and latent-defect exposure.
- BSA higher-risk-building work (post-June-2022). 15 years mandatory under BSA s.135 forward limitation.
- Historic BSA-touching work (pre-June-2022). Up to 30 years under BSA s.135 retrospective limitation.
- Principal Designer role. As long as the building stands. Effectively career-length.
Run-off premium mechanics
- First-year run-off premium approximately equal to the last trading year's annual premium.
- 6-year single-premium block typically 2-3x last annual premium for a clean-history practice.
- BSA-touching work attracts additional loading — the extended tail requires materially more insurer capital.
- Prior claims can increase run-off cost 50-200%+.
- Multi-partner firms may negotiate lower per-partner rates on shared run-off.
Cost illustration (indicative only). A 3-partner clean-history residential-only practice with £500k annual PII premium: 6-year run-off broadly £1m-£1.5m single premium. A practice with material BSA higher-risk-building historic work: multiple times higher, depending on portfolio complexity.
What Apex looks for when placing architects' run-off
- ARB registration number and Practising status of principals.
- Turnover breakdown by building type (residential/commercial/higher-risk).
- Detailed project list for BSA-touching work (all higher-risk buildings worked on).
- Principal Designer role history under BSA 2022 and CDM 2015.
- Current PII cover schedule and claims history.
- Personnel — who is retiring, who continues to practise elsewhere.
- Firm structure at cessation (traditional partnership, LLP, incorporated).
Common architects' run-off placement scenarios
- Sole-principal residential practice at retirement. Standard 6-year single-premium block; straightforward placement.
- Mid-sized practice with mixed portfolio at planned closure. 6-10 year cover; BSA elements ring-fenced.
- BSA-touching firm at cessation. Extended cover required; specialist broker essential; Lloyd's wholesale access materially widens options.
- Practice sale to successor firm. Successor-practice PI implications; deed of retirement plus run-off structuring for the retiring principals.
- Individual architect ceasing but firm continues. Individual's prior acts typically covered under firm's ongoing PI; personal supplemental cover for BSA-touching career work sometimes prudent.
Frequently asked
How long does an architects' run-off need to last?
Depends on the work profile. Non-BSA residential-only: typically 6 years. Commercial work: 6-12 years. BSA higher-risk-building work: 15 years forward, up to 30 years for pre-June-2022 acts. ARB Standard 8 requires cover adequate to the tail, not a fixed period.
What is BSA 2022 s.135 and why does it affect run-off?
Section 135 of the Building Safety Act 2022 extended the limitation period for professional-negligence claims relating to higher-risk buildings. Forward-looking work faces 15-year limitation; historic pre-June-2022 acts on higher-risk buildings face up to 30-year limitation. This forces materially longer run-off cover for affected architects.
How much does architects' run-off cost?
Typically 2-3x last annual premium for a clean-history 6-year block; materially more for BSA-touching work or prior claims. First-year premium broadly equal to last trading year's annual premium.
Can I get run-off if my practice has claims history?
Yes typically, through a specialist broker with wholesale market access. Prior-claims practices face narrower market appetite and higher premium loading. Specialist broker essential.
What about architects who worked at another firm previously?
Individual professional-liability exposure follows the individual. Where prior-firm PII covered the individual's work at that firm, and the prior firm maintains cover, the individual's tail is typically covered. Confirm at appointment.
Does run-off cover Principal Designer duties under BSA 2022?
Standard architects' run-off typically covers Principal Designer duties where they were part of the practice's work. Confirm the wording — some insurers restrict or sub-limit Principal Designer role specifically.
Can partners share a single run-off cover?
Yes typically. Firm-level run-off cover applies to all partners for work done during their partnership. Individual supplemental cover sometimes prudent for high-personal-exposure roles.
What if my practice is sold rather than closed?
Different scenario. Sale to a successor firm triggers successor-practice PI implications. The buyer may take on prior acts or the seller carries run-off; SPA determines. Specialist broker helps structure at the transaction.
How do I get run-off cover in place?
Engage a specialist broker 6-12 months before intended cessation. Complex or BSA-heavy placements may need longer. Simple clean placements can be arranged in a few weeks.
Do I still need ARB registration during run-off?
ARB registration is required for practising architects. Ceasing to practise means individual can lapse ARB registration but the professional-negligence exposure for prior acts remains. Personal run-off cover addresses that continuing exposure.