Aipedia: Building control approvers

AI and regularisation of unauthorised work

Aipedia, by the Apex broking team · Last reviewed 2026-10-30

AI can sort and analyse the historic drawings, photos and surveys behind a regularisation application, but it cannot see inside walls or verify what the owner supplied. Buyers often rely on the resulting certificate, so the limits of the review must be clear.

Part of: AI in building control approvers

In short

Regularisation deals with building work carried out without building control approval, and is usually handled by local authority building control. The evidence is often patchy: old photos, owner-supplied drawings, invoices and surveys. AI tools can organise this material and flag apparent gaps, but hidden elements such as foundations, insulation, fire stopping and structural connections cannot be confirmed from images. The inspector remains accountable (RBI code 4.2), records must show how the decision was reached (Annex 1.2), and a certificate relied on in a sale can lead to buyer claims.

How AI is used for historic work

Regularisation applications often arrive with a bundle of material from different sources: photos taken during the build, estate agent images, a builder's invoices, a structural engineer's letter and drawings prepared after the event. AI tools can sort and date the photos, extract dimensions from drawings, compare them with the work as it stands and summarise reports. Image tools may suggest what construction lies behind a finish.

These are useful aids to organising evidence. They are weak where the decision depends on what is concealed, and they cannot test whether the material supplied is genuine, complete or relates to the work in question.

The duties that apply

These duties apply whether or not AI is involved:

RBI code 3.1: only carry out restricted activities you are registered for and competent in.
RBI code 4.1 and 4.2: act diligently and remain accountable for decisions.
Annex 1.2: records must show how decisions and opinions were reached.
RBI code 5.8: record and retain the evidence, advice and judgements relied on.
OSR 3.9: inspection reports must record how the work was inspected.

See the RBI code of conduct and operational standards rules. If any part of a decision about a householder's application were made solely by automated means, the automated decision-making safeguards inserted by section 80 of the Data (Use and Access) Act 2025 (UK GDPR Articles 22A to 22D, in force 5 February 2026) could be relevant.

What can go wrong

The temptation is to let well-organised evidence stand in for opening up. A tidy AI summary of photos showing insulation being installed does not prove the insulation is continuous, the right thickness or the product shown on the invoice. Photos may come from a different property or an earlier phase. Owner-supplied drawings may show what was intended rather than what was built.

Illustrative: a local authority receives a regularisation application for a loft conversion. The owner supplies build photos and a structural calculation. An AI tool matches the photos to the drawings and reports the steel sizes as consistent. The inspector does not ask for opening up and issues a regularisation certificate. The house is sold. The buyer later finds deflection in the floor, and an engineer establishes that the steel installed differed from the calculation. The buyer's solicitor relied on the certificate.

Whether a building control body owes a duty to a later buyer depends on the facts and the law, which is not straightforward. Even so, the body may need to defend the claim, and the file will be scrutinised.

How PI usually responds

A negligence claim arising from regularisation is usually treated like any other professional negligence claim, subject to the policy terms. Local authority teams should check how their authority's insurance arrangements apply, particularly for inspectors working under contract or as consultants. For self-employed inspectors, see PI insurance for building inspectors and approvers.

Practical controls

Put these controls in place:

Decide what must be opened up or tested before relying on any photo or document.
Check that owner-supplied images relate to the property, for example by comparing fixed features.
Record which elements were verified directly and which rely on supplied evidence.
State any limitations clearly in the decision and on the file.
Keep the AI analysis with the evidence it was run on.
Do not let a tool make or communicate the decision to the householder.

Related: AI and completion certificates, AI defect detection in photos and AI-written records. Apex arranges PI for building control professionals, and a broker can check how your policy treats regularisation work and AI-assisted evidence review. See the AI in building control hub.

Sources

Frequently asked

Can AI decide whether to regularise unauthorised work?

No. The inspector remains accountable for the decision under RBI code 4.2, and records must show how it was reached. AI can organise and analyse evidence, but cannot confirm concealed elements such as foundations, steelwork or fire stopping.

How reliable are owner-supplied photos?

They can be useful but may be incomplete, from another property or from an earlier phase of work. Check them against fixed features of the building and decide what must be opened up or tested before relying on them.

Can a buyer claim if a regularisation certificate was wrong?

A buyer may try. Whether a building control body owes a duty to a later purchaser depends on the facts and the law. PI usually responds to a negligence claim subject to the policy terms, and the defence will depend on the records.

What should the file show on a regularisation decision?

It should show which elements the inspector verified directly, which rely on owner-supplied evidence, what was opened up or tested, and any limitations. Annex 1.2 of the RBI code requires records that make clear how decisions and opinions were reached.

Check your PI covers how you use AI

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Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information about how AI is used in the profession and how insurance may respond. It is not legal, regulatory or insurance advice on your circumstances, and it does not guarantee that cover will be available or on what terms.