Certificates of lawfulness of proposed works

Carrying out works that affect the character of a listed building without listed building consent is a criminal offence, and it is one of strict liability. Good faith is not a defence. An email from a conservation officer saying the works look like repair is not a defence either. A certificate lawfulness proposed works listed building application, made under section 26H of the Planning (Listed Buildings and Conservation Areas) Act 1990, is the mechanism that turns that opinion into something you can rely on.

For anyone running a repair programme on a listed building, it is the most underused tool in the system.

What the certificate establishes

The certificate confirms that specified proposed works to a listed building would be lawful because they do not require listed building consent. It is directed at the question of whether the works would affect the character of the building as one of special architectural or historic interest.

Where a certificate is issued, the lawfulness of the works described in it is conclusively presumed, provided the works are carried out as described and the position has not changed. That is the whole value of it. A prosecution cannot go behind a valid certificate for the works it covers.

What it does not do is authorise anything. It is a declaration about the existing legal position rather than a consent, so it cannot make lawful works that do in fact require consent. If the honest answer is that consent is needed, the certificate application will be refused and the applicant will have learned that before the scaffold went up.

Where the power comes from

Section 26H was inserted into the 1990 Act by the Enterprise and Regulatory Reform Act 2013, alongside heritage partnership agreements and listed building consent orders, as part of a package intended to reduce the volume of consent applications for works that plainly did not need them.

The application goes to the local planning authority. The authority must issue the certificate if it is satisfied that the works described would not affect the character of the building as a building of special architectural or historic interest, and must refuse it otherwise. A certificate can be revoked where it was obtained on false information or where material information was withheld.

This is distinct from a lawful development certificate under sections 191 and 192 of the Town and Country Planning Act 1990, which answers the separate question of whether something is development needing planning permission. On a listed building that is being altered externally, both questions can arise, and they need separate applications.

When it is worth applying for

Not for everything. The certificate costs time, and most routine maintenance is uncontroversial.

It earns its place in four situations.

1. A repair programme on a large or complex building where the same detail recurs across many elements and a single ruling settles all of them.
2. Works at the boundary between repair and alteration, such as replacing decayed window sections, relaying a floor, or renewing a roof covering with a different fixing method.
3. Works to fabric the applicant believes is modern, where the question is really about the date and significance of what is being removed.
4. Any situation where a funder, a purchaser or an insurer needs documented confirmation.

The line between repair and alteration is exactly where most of these applications sit, and our note on like for like repairs and listed building consent works through where that line tends to fall.

Information and drawings required

The burden of proof sits with the applicant, on the balance of probability. An application that describes the works loosely invites refusal, because the authority can only certify what has been described.

A well-made application contains a precise written description of the works, element by element, with quantities where relevant. It contains drawings showing the existing fabric and the proposed intervention at a scale that reveals the detail, typically 1:5 or 1:10 for junctions. It contains photographs of every element concerned, keyed to a plan. It contains a short assessment of the significance of the fabric affected, drawing on the list entry, the building's history and physical evidence, in the form a Heritage Statement would take. And it contains a specification: materials, mortar mix, fixings, finishes.

Where the age of the fabric is the issue, evidence of date matters. Earlier photographs, a paint analysis, nail and screw types, saw marks and timber conversion all carry more weight than assertion. Where recording is proposed as part of the works, a Historic Building Recording exercise to the appropriate level demonstrates that evidence will be preserved even where the physical fabric is not.

Check the current fee position with the authority before submitting, since fee schedules are revised and indexed.

How it differs from informal officer advice

Informal advice is fast, free and worth having. It is not binding on the authority, it does not bind a future officer, and it provides no protection in a prosecution brought by the authority or by anyone else.

Conservation officers move jobs. Councils reorganise. Advice given by telephone in March is difficult to evidence in October, and advice given "subject to seeing the detail" is not advice at all. The certificate exists precisely because the informal route leaves the owner carrying a criminal risk they cannot quantify.

There is also a practical benefit in the discipline. Preparing a certificate application forces the design team to describe the works precisely, which frequently reveals that two members of the team had different things in mind.

Appeal rights on refusal

A refusal is not the end. There is a right of appeal to the Secretary of State against refusal, and against non-determination within the prescribed period, and the appeal is determined on the same question the authority faced.

Check the current Planning Inspectorate procedural guide for the deadline and the forms, because the periods differ from those for listed building consent appeals and they are revised. On appeal, the evidential material carries the case in exactly the way it should have at first instance, so a refusal is often best answered by improving the evidence rather than by arguing about the reasoning.

Where the refusal is well founded, the sensible response is a listed building consent application for the works as designed. Consent applications carry no fee, and a scheme presented with the significance work already done moves faster than one starting cold.

Using it to de-risk a repair programme

On an estate or a large single building, the strongest use is strategic rather than piecemeal.

Identify the recurring details early: the window repair typology, the roof detail, the plaster repair specification, the approach to services routing. Apply for a certificate covering the ones you are confident about, apply for listed building consent for the ones you are not, and consider whether the scale of the programme justifies a heritage partnership agreement instead, which can cover a programme of works over a period.

Solar and other energy measures sit in a category of their own, because the reversibility argument does a lot of work and the visual effect does the rest. Our note on solar panels and listed building consent covers how that argument is usually framed.

One honest caveat. Authorities differ in how readily they issue these certificates, and some conservation teams treat any application as an invitation to require consent instead. That is a reason to prepare the application carefully rather than a reason to avoid it, because the alternative is proceeding on an opinion nobody has written down.

Draft your heritage documents on PlanScope and have them reviewed by a suitably accredited conservation professional before submission.

This is general guidance, not legal advice. Check the position with your local planning authority's conservation officer or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.