A professional negligence claim is basically the client saying: "You didn't just build it badly -- your professional advice/design/judgment fell below the standard of a competent pro, and that's cost me money."
That can hit architects, engineers, QSs and project managers -- but also design-and-build contractors and specialist subs with design responsibility. It's where your professional indemnity (PI) policy is meant to earn its keep.
1. What "professional negligence" actually means
To nail you for professional negligence, a claimant broadly has to show:
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You owed them a duty of care as a professional (by contract or in tort).
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You breached that duty -- you fell below the standard of a reasonably competent person in your shoes.
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That breach caused them loss (not just "it was wrong", but "because of that error, we suffered this cost").
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The loss is real, not too remote, and they're within the time limits to sue.
So it's not "any problem = negligence". It's about your professional decisions (design, spec, advice, approvals, certification, inspections), not just workmanship.
2. Time limits: when a negligence claim "times out"
The Limitation Act 1980 (and related rules) sets the deadlines. If they sue too late, you get a limitation defence.
Very simplified headline points:
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Simple contract claims (most professional appointments not executed as deeds): usually 6 years from the breach (e.g. when you issued the defective design/spec).
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Negligence / tort claims: generally 6 years from damage or up to 3 years from date of knowledge of the damage, subject to a 15-year long-stop from the act of negligence.
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Deeds / some Building Safety Act contexts can bring in longer periods (often 12 or 15 years from the relevant act).
The detail is messy, but the takeaway is: claims can land many years after you finished a job, and you should always let your lawyers/insurers check limitation -- it can be a complete defence if the clock has run.
3. Your first moves when a negligence letter lands
Rule one: don't panic and don't start firefighting alone. You've got two immediate priorities -- evidence and insurance.
Do this, in this order:
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Read the letter carefully -- is it a formal Letter of Claim under a pre-action protocol, or just a complaint? What exactly are they alleging (design, advice, certification, inspection, coordination)?
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Don't admit liability or argue back on the merits in the heat of the moment. Keep your reply (if any) neutral and holding-pattern only.
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Pull the file -- contracts/appointments, emails, drawings, calcs, meeting minutes, site reports, certificates, photos. Get everything into one place and backed up.
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Notify your PI insurer/broker immediately in line with the policy wording -- often you must notify not just claims but "circumstances which may give rise to a claim".
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Let the insurer steer the legal response -- most PI policies give them a say on appointing solicitors and on strategy. If you freelance admissions or settlements without them, you can prejudice cover.
PI policies are usually claims-made: they respond to claims/circumstances notified during the policy period, not when the work was done. Late notification is one of the biggest reasons claims get declined.
4. How PI insurance fits into all this
For anyone giving construction-related professional services (design, spec, inspections, advice), PI is the safety net.
Key practical points:
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It covers (subject to terms/exclusions) your civil liability for negligent professional services -- typically the cost of putting right design/spec/advice errors and associated financial loss.
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It's claims-made -- you must have cover in place when the claim is made or circumstance notified, not just when you did the work.
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Notification conditions are often a condition precedent -- if you don't notify "as soon as possible" or "immediately" after becoming aware of a circumstance, the insurer can refuse cover.
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Many policies include a "mitigation of loss" or similar clause: with insurer consent, they may cover some reasonable costs of remedial works taken to head off a bigger claim.
So the worst thing you can do is sit on a serious complaint because "we might be able to sort it ourselves". From the insurer's point of view, that's unreported risk.
5. Steadying the ship if you're accused
Once the insurer and lawyers are looped in, your job is to be the grown-up in the room: factual, organised, and not defensive.
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Get your timeline straight -- when you were appointed, what you were actually responsible for, key design/inspection milestones, when problems first showed up.
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Be honest about scope -- lots of "negligence" claims are really about scope creep or things that were never in your remit. Clear scope can be a complete answer.
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Keep communication controlled -- from now on, major letters go via or with sign-off from your appointed lawyers/insurers; you keep site and business calm.
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Watch limitation -- your legal team will check whether some or all of the alleged loss is time-barred, especially on older projects. Don't concede anything on dates casually.
Handled properly, a lot of "professional negligence" noise either resolves commercially or gets cut down sharply once duty, scope, causation and limitation are tested.
Professional negligence claim -- first 72 hours checklist
When a negligence letter lands, run this, in order:
- Read, don't react -- work out who's claiming, what project, what they say you did wrong (design, advice, inspection, certs), and roughly how much they want.
- Do NOT admit liability or argue the merits in your first reply. At most, acknowledge receipt and say you're taking advice.
- Pull the project file -- appointments, contracts, emails, drawings, calcs, meeting notes, site reports, certificates, photos, and any earlier complaints on the same issues.
- Notify your PI insurer/broker in writing immediately, attaching the claim letter and a short factual summary; ask them to confirm it as a claim or circumstance under the policy.
- Stop side deals -- don't agree refunds, remedial scopes, or "goodwill" payments without insurer sign-off, or you risk prejudicing cover.
- Map the timeline -- date of appointment, key deliverables, when issues first arose, who said what and when. This feeds straight into both liability analysis and any limitation defence.
- Identify your scope and exclusions -- be clear what you were actually engaged to do (and not do); many claims fall away when scope is properly understood.
If you do just those things in the first few days, you give both your insurer and your lawyer a fighting chance to keep a bad situation under control.
Disclaimer: SiteKiln gives you plain-English information, not legal advice. Talk to a solicitor before making big decisions on live disputes.
What to do next
- If a negligence letter has landed, notify your PI insurer or broker in writing immediately -- do not wait.
- Do not admit liability or agree refunds, remedial scopes or goodwill payments without insurer sign-off.
- Pull the full project file: appointment, contract, emails, drawings, calculations, meeting notes, site reports, certificates and photos.
- Map your timeline: date of appointment, key deliverables, when the issues first came up, and who said what.
- Be clear about your actual scope -- many negligence claims fall away when scope and exclusions are properly understood.
Sources
- Limitation Act 1980 -- https://www.legislation.gov.uk/ukpga/1980/58/contents
- Building Safety Act 2022 -- https://www.legislation.gov.uk/ukpga/2022/30/contents
- Pre-Action Protocol for Construction and Engineering Disputes -- https://www.justice.gov.uk/courts/procedure-rules/civil/protocol/prot_ced
- Pre-Action Protocol for Professional Negligence -- https://www.justice.gov.uk/courts/procedure-rules/civil/protocol/prot_neg
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