Guides · Professional negligence · Series
The design was wrong. Or nobody checked the build.
What the law says when an architect or engineer's work costs you money: what a claim against a designer involves, telling a design defect from bad workmanship, inspection and certificates during the build, planning and building regulations, a structural engineer's report on a purchase or extension, budgets and cost estimates, how loss is measured, the construction pre-action protocol and the Technology and Construction Court, and the time limits, including the Defective Premises Act.
9 guides · about 47 minutes to read the lot · England & Wales
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Architect and engineer negligence, start to finish
Can I claim against an architect or engineer? What a negligence claim involves
What a claim against an architect or engineer involves in England and Wales: who counts as one, where the duty comes from in contract and tort, the reasonably competent professional standard, the scope of the appointment, insurance, and why a complaint to ARB or a professional body is not a claim for compensation.
7 min02Design defect or bad workmanship? When it's the architect, not the builder
How the law separates a design defect from poor workmanship, what happens when a builder follows a flawed design, how responsibility is shared when both are at fault, and why a net contribution clause in an architect's appointment can matter if the builder has gone bust.
5 min03Failure to inspect or certify: the architect as contract administrator
What an architect or other professional engaged to inspect the works or administer the building contract is expected to do, what the courts have said about periodic inspection, why a defect the inspector missed is not automatically negligence, and liability for certifying too much.
5 min04Planning and building regulations: when the architect or engineer got it wrong
Claims against an architect or engineer over planning permission and building regulations: what the designer's duty covers, the designer duties in the Building Regulations in England since October 2023, how long councils have to take enforcement action, and what the loss can include.
5 min05Structural engineer negligence: a report on a purchase or a design for an extension
Claims against a structural engineer in England and Wales: a pre-purchase report that missed or misjudged a problem, or calculations and design for an extension or alteration that were wrong. Covers the scope of the instruction, who the engineer owed a duty to, building control, and which pre-action protocol applies.
5 min06The architect's budget was wrong: cost overruns and negligent estimates
When an architect or other consultant gets the cost of a project badly wrong: whether advising on budget was part of the job, what the High Court said in Riva v Foster + Partners about designing to a client's budget, and how the law looks at the loss when a scheme cannot be built for what was promised.
4 min07Architect and engineer negligence: how loss is measured
How the courts in England and Wales measure loss in claims against architects and engineers: putting the client in the position they should have been in, cost of repair against loss of value, the reasonableness limit from Ruxley v Forsyth, wasted expenditure, the limits on economic loss claims in tort after Murphy v Brentwood, and caps in the appointment.
5 min08Claims against architects and engineers: the construction pre-action protocol and the TCC
Why claims against architects and engineers follow the Pre-Action Protocol for Construction and Engineering Disputes rather than the professional negligence protocol, the steps and time periods it sets, the pre-action meeting, adjudication, and how the Technology and Construction Court deals with these claims.
6 min09Time limits for claims against architects and engineers
How long there is to bring a claim against an architect or engineer in England and Wales: six years in contract (twelve for a deed), six years in negligence with the date-of-knowledge extension and fifteen-year longstop, and the longer periods for Defective Premises Act claims introduced by the Building Safety Act 2022.
5 minFrequently asked
Can I claim against an architect or engineer?
Yes, if they failed to use the reasonable skill and care of a competent member of their profession in the work they were engaged to do, and that failure caused you financial loss. A designer does not guarantee a perfect building, and a defect in the finished work is not on its own proof that the architect or engineer was negligent.
Is it the builder's fault or the architect's?
It can be either, or both. A defect that follows the drawings points to the design; one that departs from them points to the builder. Where both are responsible for the same damage, each can be liable to you, and they can claim a contribution from each other (Civil Liability (Contribution) Act 1978).
Which pre-action protocol applies?
The Pre-Action Protocol for Construction and Engineering Disputes, which says it applies to professional negligence claims against architects, engineers and quantity surveyors. The Professional Negligence Pre-Action Protocol says it is not intended to apply to those claims. The construction protocol expects a letter of claim, a response within 28 days and, normally, a pre-action meeting.
How long do I have?
Generally six years from the breach of contract (twelve if the appointment was made as a deed), or six years from when damage was suffered in negligence or, if later, three years from the date of knowledge, subject to a fifteen-year longstop (Limitation Act 1980, ss.2, 5, 8, 14A and 14B). Claims under the Defective Premises Act 1972 follow their own periods, extended by the Building Safety Act 2022.
When you’ve read enough
Work out where you stand in five minutes.
The check asks for the survey date, the date you found the problem, a value band and what you hold. It gives you an estimated deadline, the likely court track and a report you can take to a solicitor — and, only if you ask, an introduction to one.