The ARB does not set a fixed minimum limit of indemnity for every architect — it sets a floor, and then leaves the rest to the practice and its broker.
Every architect on the UK register is bound by the Architects Code: Standards of Conduct and Practice, published by the Architects Registration Board. Standard 8 of that Code requires registered architects to hold adequate and appropriate professional indemnity insurance. That sounds simple. In practice it sits at the intersection of statute, regulator guidance, the Building Safety Act 2022, and the commercial demands of main contractors and clients — and getting it wrong puts your registration, not just your balance sheet, at risk. This guide explains how the ARB requirement actually works, what counts as “adequate”, how it interacts with RIBA membership, and where the BSA has reset the conversation for residential work.
The Architects Act 1997 is the statutory backbone. Section 4 sets out who may be entered on the Register of Architects, and section 13 protects the title — only those on the ARB register may use the term “architect” in business or practice in the UK. The ARB administers the register and issues the Code under its statutory powers. Standard 8 is the operative paragraph for insurance, and the ARB’s accompanying guidance fleshes out what “adequate and appropriate” means in working terms.
The current ARB position is that the minimum level of cover for most registered architects is £250,000 each and every claim, with a higher floor for work falling within scope of the Building Safety Act regime. ARB guidance has aligned the residential floor at £1,000,000 for any architect carrying out work on dwellings, reflecting the longer tails of liability and the higher value of remediation that the BSA has crystallised. These are floors, not targets. A sole practitioner doing small extensions to single dwellings sits in a different risk universe to a 40-person practice working on mixed-use schemes for institutional developers, and the limit needs to reflect that.
“Adequate and appropriate” is the phrase that does the heavy lifting. ARB does not prescribe wordings. It expects each architect to consider the nature, scale, and complexity of work, the financial standing and demands of clients, contractual obligations including collateral warranties and third-party rights, and the exposure carried from past projects on a claims-made basis. The standard also expects you to be able to demonstrate that you have thought about it — not just that you bought a policy off a renewal invitation.
Architects often conflate ARB registration with RIBA membership. They are different things. ARB is the statutory regulator established under the Architects Act 1997; you cannot call yourself an architect in the UK without being on the ARB register. RIBA is a chartered membership body. Its Code of Professional Conduct also requires PI cover and provides additional guidance, but RIBA cannot remove you from the architects’ register. Only ARB can do that.
A standard UK architects’ PI policy is written on a claims-made basis with a single combined limit each and every claim, plus defence costs in addition or in some markets within the limit. The insuring clause typically covers civil liability arising from the conduct of the professional business, which is broad enough to capture design negligence, specification errors, late delivery, breach of copyright in drawings, and inadvertent breach of contract.
To meet Standard 8, the policy needs to do four things at once. It must respond to the architect’s full scope of past and present services; it must carry a limit at or above the ARB floor relevant to the work undertaken; it must include defence costs in a way that is not eroded so quickly by a single claim that the protection is illusory; and it must include the run-off provisions necessary to cover liabilities arising after the practice has ceased to trade.
The £250,000 / £1,000,000 floors are minimums. Any architect signing a building contract that requires £2m, £5m or £10m of cover is committing the practice to that contractual standard for the duration of the limitation period — and the policy at renewal needs to match the highest live commitment, not the regulatory floor. Where contracts demand “each and every claim” rather than “in the aggregate”, that distinction needs to be checked on the schedule. Underwriters do not always default to the same basis.
Contracting out of the duty of fair presentation under the Insurance Act 2015 is rare in the architects’ market, but the duty under section 3 of that Act still bites every renewal. The practice must disclose every material circumstance. Section 8 sets out the proportionate remedies for breach. Section 11 limits an insurer’s ability to rely on terms that have nothing to do with the actual loss. These are the architecture of the modern PI policy, and brokers should walk through each one at placement.
Consider a typical six-architect practice in the North West with a £900,000 fee income, a residential conversion portfolio, and one live mixed-use scheme containing flats. The practice carries £1,000,000 each and every claim because that satisfies ARB Standard 8 for residential work and matches its standard appointment.
Eighteen months into the mixed-use scheme, the main contractor demands £5,000,000 cover under the building contract for the duration of the works and a 12-year warranty period after practical completion. The practice’s broker arranges a mid-term increase to £5,000,000, and at the next renewal carries that limit forward because the BSA exposure means the contractual undertaking outlives the works.
Two years later, a defects claim is notified relating to fire-stopping detailing on a different residential refurbishment from four years earlier. The policy in force at notification is the £5,000,000 wording. The claim settles at £180,000 plus £45,000 of defence costs. The practice’s limit was never tested, but its continuity of cover and retroactive date were. The single most valuable decision the practice made was not letting the policy lapse during a broker change three years earlier.
Apex’s view: The £250,000 / £1,000,000 floors are an ARB minimum, not a market benchmark. We continue to see practices renewing on the regulatory floor when their largest live appointment demands four or five times that limit — and the broker has not flagged it. The hard question at every renewal is not “what does ARB require” but “what does the highest live contract require, projected over the longest plausible limitation period”. On residential schemes within scope of the Building Safety Act 2022, that horizon is now 30 years for historic work. Plan the limit accordingly.
Apex Insurance Brokers serves UK professional services firms and commercial businesses. Call 0117 325 0027, email hello@apexinsurancebrokers.co.uk, or request a quotation.
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