Reviewed by Matthew Bartlett, Director · Last reviewed 8 July 2026
Architects' professional indemnity in the UK is priced by an underwriter reading a submission, not by a rate card. The Architects Registration Board (ARB) requires adequate and appropriate cover and does not fix a specific limit. The insurance market prices architects on fee income, discipline mix, project types, contract exposure, claims history, and, since 2022, on the firm's exposure to residential higher-risk buildings under the Building Safety Act. This page sets out what actually drives the number for architectural practices and how Apex Insurance Brokers approaches an architects' PI submission.
Fee income is the starting point. Underwriters rate on gross fee income for the practice year, and the rate itself moves with the profile of the work. Small residential extension work, one-off houses, and interior projects sit at one end of the spectrum. Multi-storey residential development, mixed-use schemes, health, education, and any exposure to higher-risk buildings under the Building Safety Act 2022 sit at the other. A firm with 60% residential above 18 metres will attract a materially different rate to a firm doing the same fee income on small commercial fit-outs.
Discipline mix and project role matter. Lead designer roles, principal designer under the CDM Regulations, or novated appointments with design-and-build contractors all carry different risk profiles from a traditional consultant role. Fire safety, cladding, and external wall systems are read separately and priced accordingly given the market's post-2017 experience. Claims and circumstances history is read on substance: an open matter with a reserve is priced very differently to a closed-nil circumstance from six years ago.
Limit of indemnity is negotiated on the client's contract requirements and on the practice's actual risk. Many architectural appointments now specify limits of £5 million to £10 million each and every claim, sometimes in the aggregate on residential work. Net contribution clauses in the appointment, fire safety exclusions in the policy, and the difference between each-and-every and aggregate wordings are all material to the cost and the cover.
ARB Standard 8 of the Architects Code requires architects to have adequate and appropriate professional indemnity insurance in place to cover the work they do. ARB does not prescribe a specific minimum limit but requires cover to be appropriate to the nature and value of the work. The ARB also publishes a Guidance Note on PII that sets out the expectation that architects will hold cover on a claims-made basis with appropriately-rated insurers.
RIBA Chartered Practice status carries its own PII requirement: a minimum limit of £250,000 for practices with turnover up to £100,000, £500,000 for turnover up to £200,000, and £1 million above that, subject to the practice's own risk profile. Many chartered practices carry limits well above the RIBA floor because their appointments require it.
The Building Safety Act 2022, in particular section 135 which amended the Defective Premises Act 1972 to extend the limitation period for dwellings to 30 years retrospectively and 15 years prospectively, has changed the shape of the architects' PI market. Insurers rate exposure to residential design work materially differently as a result, and fire safety and cladding exclusions have become common on renewals for firms with historic exposure.
Apex Insurance Brokers is authorised and regulated by the Financial Conduct Authority (firm reference number 724952) and places architects' PI with insurers that have appetite for the sector. We are a named-broker practice: Matt Bartlett or a named colleague reads every submission personally, drafts the presentation, and negotiates on the practice's behalf.
Our client retention rate across the book is approximately 95%. We work with sole practitioners, small studios, and multi-disciplinary practices. Our approach is to engage with the practice on its actual project pipeline and residential exposure early, so that the presentation reflects the current risk rather than a rolled-forward version of last year's figures.
Any range published on a web page is a starting point for conversation, not a quote. With that on the record: a sole practitioner or two-person studio doing lower-risk work at modest fee income and clean claims will typically see primary PI premiums starting in the low thousands of pounds a year. Practices with material residential exposure, particularly to buildings above 18 metres or to historic cladding work, should expect terms to reflect that materially.
Mid-sized practices with a mixed commercial book often pay a rate on fee income in the low to mid single digits of a percent, but the number moves sharply with residential exposure, fire safety wording, and limit purchased. Practices with clean records and a lower-risk work profile should expect the market to compete for them. The specific figure comes out of the underwriter's assessment of the submission, not from a table.
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