Less than substantial harm: appealing a heritage refusal

A less than substantial harm appeal is won on two things: pinning the harm precisely within the lower part of the scale, and evidencing public benefits that are real, secured and public. The phrase itself misleads people. Less than substantial harm is not minor harm, and it does not reduce the weight the decision maker must give to conserving the asset. It is a category, and everything inside it still attracts great weight under national policy and considerable importance and weight under the statutory duties.

What the refusal has to establish

Read the reason for refusal and identify three things the council must have decided.

Which heritage asset is affected, and whether it is designated. What its significance consists of, whether archaeological, architectural, artistic or historic interest. And where on the scale the harm sits, from no harm through less than substantial to substantial.

Many refusals skip the second step. A reason for refusal that asserts harm to the setting of a listed building without saying what contribution the setting makes to significance has left out the analysis the whole test depends on, and that gap is often the strongest point in an appeal.

The statutory duties that sit above policy

Sections 16 and 66 of the Planning (Listed Buildings and Conservation Areas) Act 1990 require special regard to the desirability of preserving a listed building, its setting and any features of special architectural or historic interest. Section 72 requires special attention to the desirability of preserving or enhancing the character or appearance of a conservation area.

The Court of Appeal in East Northamptonshire District Council v Secretary of State, usually cited as Barnwell Manor, held that a decision maker must give considerable importance and weight to that desirability, and that finding harm to be less than substantial does not permit a simple balancing exercise as though the duty did not exist.

The practical drafting consequence is that an appeal statement should deal with the statutory duty separately from the policy test, and should say in terms that the duty has been applied. Inspectors notice when it has not been.

Where the category gets misused

Two errors recur, and they run in opposite directions.

Councils sometimes treat less than substantial harm as a finding that requires refusal unless the benefits are exceptional. That is the test for substantial harm, not for this category. National policy asks for the harm to be weighed against the public benefits of the proposal, including securing the optimum viable use of the asset.

Appellants sometimes treat less than substantial as a synonym for slight, and move quickly to the benefits. That invites an inspector to find the harm at the upper end of the category and to conclude that thin benefits do not outweigh it.

Both are avoided by being specific. Say where within the category the harm falls, explain why, and show your reasoning about what is lost. An assessment that concludes harm at the lower end of less than substantial, having explained that the affected element is a later addition of limited interest and that the setting contributes to significance mainly through one view which is retained, gives the inspector something to agree with.

Evidencing significance and setting

Significance comes first, always. Historic England's advice on statements of heritage significance and on managing significance in decision taking sets the approach, and its guidance on the setting of heritage assets provides a staged method for assessing setting: identify the assets affected, assess whether and how setting contributes to significance, assess the effect of the proposal, explore ways to maximise enhancement and minimise harm, and record the process.

Use it as a structure rather than a citation. A Heritage Statement that works through those steps, with photographs from the views that matter and a plan showing where they were taken, does more than a chapter of policy quotation.

Where below-ground archaeology is engaged, an Archaeological Desk-Based Assessment drawing on the Historic Environment Record establishes what is likely to survive and what the proposal would disturb. Where fabric will be lost or altered, a Historic Building Recording at the appropriate Historic England level is both evidence and mitigation, and offering it by condition is a normal part of the package.

Public benefits that count

The guidance is clear that public benefits should flow from the proposal, should be of a nature or scale to be of benefit to the public at large, and need not be visible or accessible to the public to count.

Benefits that regularly carry weight include bringing a heritage asset back into use, funding repairs that secure the asset's long-term future, removing a harmful later addition, delivering housing where there is a shortfall, and improving public access or interpretation. Benefits that carry little weight include the applicant's own financial return and general assertions of economic activity with nothing behind them.

Secure them. A benefit that depends on a repair schedule should be tied to a condition or an obligation, with a trigger point. Inspectors discount unsecured benefits, and an appellant who offers a heritage repair package without a mechanism has offered an intention.

Optimum viable use, and how to evidence it

Where the appeal concerns a building at risk, or one whose current use is failing, the optimum viable use argument does real work. National guidance treats it as the use that causes the least harm to significance while remaining economically viable, and it is not automatically the most profitable use.

Evidencing it means showing the alternatives were tested. A schedule of uses considered, with a short appraisal of each and the reason it was rejected, is the document inspectors look for. Marketing evidence helps where the argument is that no other use came forward, and it needs to show the period, the price, the agent and the enquiries received, rather than an assertion that the building was marketed.

Where repair costs drive the case, a condition survey with a costed schedule of works carries more weight than a headline figure. And be honest about the deficit. An appellant who accepts that the scheme produces a modest return, and shows the arithmetic, is more persuasive than one claiming the project is marginal without any figures.

Non-designated assets

Where the building is a local heritage asset rather than a listed building, the statutory duties do not apply and the policy test is different. National policy asks for a balanced judgement having regard to the scale of any harm or loss and the significance of the asset.

That is a materially lower bar, and the appeal should say so plainly rather than arguing the case as though the designated asset test applied. Confirm the status from the local list and the National Heritage List for England, because officers occasionally treat a building in a conservation area as though it were listed.

Putting the appeal together

Order the statement so the inspector can follow the same reasoning they will have to write.

1. Describe the asset and its significance, element by element.
2. Assess the effect of the proposal on each element, and reach a level of harm with reasons.
3. Apply the statutory duty expressly.
4. Set out the public benefits, with the mechanism securing each.
5. Carry out the balance, and say why the benefits outweigh the harm given the weight the duty requires.

Written representations suit most heritage appeals where the argument is documentary. A hearing is worth requesting where the significance judgement depends on being in the building, and an inspector who can stand in the room while the point is made will often reach a clearer view than one reading a photograph.

This is general guidance rather than legal advice. Check the position with your local planning authority, the conservation officer or a qualified professional before relying on it.

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