Start-up PII · Architects

PI insurance for start-up architectural practices — the ARB-compliant first year

Reviewed by Matthew Bartlett, Director, Apex Insurance Brokers Limited (FCA FRN 724952) · Published 14 July 2026

Opening a new architectural practice requires PII ‘adequate’ to the risk under ARB Standard 8. There is no fixed minimum limit as with the SRA MTC — the standard is qualitative. Building Safety Act 2022 s.135 adds material weight to the sizing conversation for anything touching higher-risk buildings.

The ARB requirement

ARB Standard 8 requires PII ‘adequate’ to the practice. There is no fixed minimum limit. ARB does not publish detailed underwriting criteria; the standard is qualitative and enforced through ARB investigation where there is a specific complaint or a firm response to a claim.

In practice, most start-up practices carry £250,000 to £1,000,000 for residential-only work, and £1m to £5m for commercial or higher-risk building work. The BSA 2022 has raised the effective floor for anything touching higher-risk buildings.

Building Safety Act 2022 s.135 — new firm implications

Section 135 of the BSA extended the limitation period for negligence claims relating to higher-risk buildings to 30 years for past acts and 15 years going forward. A new practice designing higher-risk buildings acquires a very long tail of potential liability from day one.

PII must respond to acts up to 30 years old for buildings completed before June 2022; 15 years for buildings completed after. Run-off cover requirements therefore need long tails.

Practice-area rating

  1. Residential-only, non-BSA — the lowest-friction start-up profile.
  2. Small commercial — office fit-out, retail, restaurants — slightly higher rating.
  3. Higher-risk buildings under BSA (>18m or >7 storeys with residential) — higher rating, longer-tail exposure.
  4. Principal Designer role under BSA 2022 — specific PII underwriting question.
  5. Contract-administrator or CDM Principal Designer — broader duty scope.
  6. Design-and-build sub-consultant or novated designer — different market appetite.

Run-off from the previous employer

A departing architect from an existing practice continues to enjoy PII cover under the old practice's policy for prior acts done there, provided the old practice maintains PII. There is no mandatory ARB run-off requirement equivalent to the SRA six-year rule — but the previous practice is expected to hold PII ‘for a reasonable period after cessation’ under ARB standards.

Confirm: (1) prior acts at the old practice are captured under the old practice's policy; (2) old practice will maintain PII for the relevant tail; (3) whether the departing architect is named on the old policy specifically.

First-year sizing

  1. Turnover estimate for year 1 — drives the base premium.
  2. Building types — residential (which sub-type), commercial, higher-risk.
  3. Fee-generation basis — percentage of construction cost, fixed fee, hourly.
  4. Principal Designer role under BSA — yes/no with related fee income.
  5. Personal claims history of the founding architect(s).
  6. Cover limit choice — qualitatively adequate for the practice profile.

What a start-up premium typically reflects

The market prices a new architectural practice against turnover, building types, BSA exposure and principal claims history. Sole-principal residential-only practices sit at the low end. Practices doing higher-risk building work or Principal Designer roles sit materially higher.

Apex quotes what the market returns after a proper presentation. Avoid template quotes without a full profile.

Frequently asked

Do I need ARB-approved PI insurance for a new practice?
You need PII 'adequate' to the practice under ARB Standard 8. There is no ARB-approved insurer list. Any PI insurer able to write architects' cover is acceptable to ARB provided the cover is genuinely adequate to the risk.
What is the minimum PI limit for a start-up architectural practice?
ARB does not publish a minimum. In practice, residential-only sole practitioners carry £250k to £1m; small commercial work £1m to £5m; anything touching higher-risk buildings under BSA 2022 typically £2m to £10m or more. Sizing is qualitative under ARB Standard 8.
How does BSA 2022 s.135 change first-year PI decisions?
BSA 2022 s.135 extended limitation for negligence relating to higher-risk buildings to 30 years for pre-June-2022 acts and 15 years going forward. A new practice takes on a long tail of potential liability from day one for any BSA-touching work. Run-off requirements are correspondingly long.
Can I get PII if I only do residential extensions and refurbishments?
Yes, and this is the lowest-friction start-up profile. Most PI insurers will write a residential-only sole practitioner. Premium is modest by professional-firm standards.
What about RIBA membership — does it change PII?
RIBA membership does not change ARB obligations. RIBA has its own recommended PII levels for members; they are guidance, not requirements. Non-RIBA architects still need PII adequate under ARB Standard 8.
How long does run-off need to last for an architect closing a practice?
For non-BSA work, typically six to twelve years post-cessation depending on limitation risk. For BSA-touching work, up to 15 or 30 years. Discuss with the specialist broker at cessation.
Do I need PI cover for Principal Designer duties under BSA 2022?
Yes, if you are formally appointed as Principal Designer for a higher-risk building project. This is a specific PII underwriting question and some insurers exclude Principal Designer duties as standard. Confirm at inception.
How much does start-up architects' PI cost?
Highly variable. Sole-principal residential-only can be low four figures; small practice doing mixed residential and small commercial mid four figures; anything doing higher-risk BSA work materially more. Apex quotes what the market returns.

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