ARB minimum PI cover for architects: £250k each and every, and how run-off works

The Architects Registration Board (ARB) sets the minimum PI cover for registered architects in private practice through its Code of Conduct and Practice. Standard 8 of the ARB Code requires architects to have adequate and appropriate insurance cover for themselves, their practice and their employees. The ARB's guidance sets the minimum at £250,000 each and every claim for architects whose practice gross fee income does not exceed £100,000, with a higher amount expected where income or risk profile is greater.

How "each and every" differs from aggregate

An each-and-every-claim limit applies separately to each claim notified during the policy period. A £250,000 each-and-every limit means each claim is met up to £250,000, with no cap on the total the insurer may pay across the policy year. This contrasts with an aggregate limit, which caps the insurer's total exposure for the year regardless of how many claims attach.

The ARB minimum is each-and-every. In practice, most architects buy more than the minimum, and many insurers will not write a primary policy below £500,000 or £1 million because of the cost-to-write ratio. Where the practice acts on residential or commercial schemes of any size, the £250,000 floor is rarely enough; the cost of defending a single claim can absorb it before damages are considered.

Run-off and retirement

Standard 8 also requires architects to maintain run-off cover for at least six years after ceasing to practise. Run-off is a continuation of claims-made cover that responds to claims notified after the practice has closed but arising from work done while it was open. Two points often catch practices by surprise.

• Six years is a minimum, not a recommendation. Limitation under the Defective Premises Act 1972, as extended by section 135 of the Building Safety Act 2022, can reach back 30 years for dwellings. An architect who completed residential work before 28 June 2022 may be exposed for far longer than the six-year ARB minimum.
• Run-off premiums are paid up front in the first year and reduce in subsequent years, but the practice has no ongoing income to fund them. A retiring sole practitioner who has not budgeted for run-off can face a difficult cash position at exit.

Sole practitioners and small practices

Our architects PI insurance guide covers limit-setting, run-off planning and the interaction with the Building Safety Act 2022 in more depth. Practices that combine architecture with broader design services — interiors, branding, product, exhibition — should also consider the position set out in our designers PI insurance guide, since the design risk in those activities is not always covered by an architect-specific wording.

Costs in addition or costs inclusive

A material question on any architect's policy is whether defence costs are paid in addition to the limit or eroded from it. A £250,000 limit costs-inclusive can be reduced to nothing by defence costs alone in a complex claim. Costs-in-addition wording preserves the indemnity limit for damages. The ARB does not mandate either basis; the market offers both.

Disclosure on the proposal

Architects' proposal forms typically ask about residential exposure, HRB involvement, value of largest project, and overseas work. The duty of fair presentation under the Insurance Act 2015 applies to commercial customers; for sole practitioners trading as individuals, the consumer test under the Consumer Insurance (Disclosure and Representations) Act 2012 may apply instead. The distinction affects what is required of the architect at proposal.

Architects considering retirement, succession, a change of practice structure, or a move into design-and-build collaboration may want to take advice on the limit, the basis and the run-off horizon together, rather than treating them as separate decisions.