Heritage Harm and the Balancing Exercise: What the Case Law Actually Says

Heritage is the area of planning most likely to end up in court. The reason is straightforward: the policy framework requires a balancing exercise between harm to heritage significance and public benefits, and that balance involves judgement. Where there is judgement, there is scope for challenge.

But the legal framework is now well established through a series of important court decisions. Understanding what the case law actually says — rather than what people assume it says — is essential for anyone proposing development that affects heritage assets.

The December 2024 NPPF sets out a clear hierarchy for heritage decision-making. Paragraph 205 states that when considering the impact of a proposed development on the significance of a designated heritage asset, **great weight should be given to the asset's conservation** irrespective of whether any potential harm amounts to substantial harm, total loss, or less than substantial harm to its significance.

This "great weight" requirement is not discretionary — it applies in every case where a designated heritage asset is affected. It applies to Grade II listed buildings just as it applies to Grade I. It applies to conservation areas. It applies to the setting of heritage assets as well as their physical fabric.

Paragraph 207 deals with **substantial harm or total loss**. Where a proposal would lead to substantial harm or total loss of significance, consent should be refused unless the substantial harm or total loss is necessary to achieve substantial public benefits that outweigh the harm, or unless all four conditions in paragraph 207(b) are met — which essentially require that the asset has no viable use, charitable transfer has been explored, and the harm is the minimum necessary.

Paragraph 208 deals with **less than substantial harm** — the category that applies to the vast majority of heritage cases. Where a proposal would lead to less than substantial harm, that harm should be weighed against the public benefits of the proposal. This is the "balancing exercise" that dominates heritage planning.

The most important heritage case in planning law is Barnwell Manor Wind Energy Ltd v East Northamptonshire District Council [2014] EWCA Civ 137. The Court of Appeal established that the statutory duty under Section 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 — to have "special regard" to the desirability of preserving listed buildings and their settings — requires decision-makers to give **considerable importance and weight** to any harm to a listed building or its setting.

This goes further than simply noting the harm. The Barnwell Manor principle means that when a decision-maker finds harm to the significance of a listed building, they must treat that harm as having considerable weight in the planning balance. A finding of "less than substantial harm" under NPPF paragraph 208 does not mean the harm is unimportant — it means it falls below the threshold of substantial harm, but it still carries considerable weight by virtue of the statutory duty.

The practical consequence is significant. Decision-makers who identify heritage harm and then dismiss it as minor — or who fail to give it the weight required by Section 66(1) — are vulnerable to legal challenge. Many planning committee decisions have been quashed on this basis.

Bedford Borough Council v Secretary of State for Communities and Local Government [2013] EWHC 2847 (Admin) reinforced the Barnwell Manor principle and clarified its application. The High Court held that a decision-maker who correctly identified less than substantial harm but then gave it insufficient weight in the planning balance had erred in law.

The Bedford Borough case is important because it confirmed that the balancing exercise under what is now paragraph 208 is not a simple cost-benefit analysis. The decision-maker must first identify the harm, then apply the statutory duty of "special regard" (which imports considerable weight), and only then weigh that weighted harm against the public benefits.

Less than substantial harm is not a single category — it is a spectrum. At one end, harm may be negligible; at the other, it may be just below the threshold of substantial harm. The position on the spectrum affects the weight to be given to the harm and, consequently, the level of public benefits needed to outweigh it.

Inspectors and officers routinely place harm on this spectrum using language such as "at the lower end of less than substantial harm," "moderate less than substantial harm," or "at the upper end of less than substantial harm." Our analysis of appeal decisions shows that the position on the spectrum is often the decisive factor: schemes causing harm at the lower end are far more likely to be approved in the planning balance than those at the upper end.

**The key factors that determine position on the spectrum include:**

**Proximity and intervisibility.** Development that is directly visible from or adjacent to a heritage asset is more likely to cause harm at the upper end. Development that is screened by existing buildings, topography, or mature vegetation causes less harm.

**Contribution to significance.** The setting of a heritage asset contributes to its significance to varying degrees. A rural farmhouse whose significance derives partly from its agricultural setting will be more harmed by suburban development than one whose significance is primarily architectural.

**Quality of design.** Inspectors consistently note where proposed development is of high design quality and responds sensitively to heritage context. Good design does not eliminate harm, but it can reduce it on the spectrum.

**Reversibility.** Harm that is reversible — for example, a temporary structure or a use that can be discontinued — carries less weight than permanent and irreversible harm.

Under paragraph 208, less than substantial harm must be weighed against the public benefits of the proposal. Public benefits are broadly defined and can include:

**Housing delivery** — particularly affordable housing, which inspectors consistently identify as a significant public benefit. In authorities that cannot demonstrate a five-year housing land supply, the weight given to housing delivery is substantial.

**Economic benefits** — job creation, local spending, business rates, and economic regeneration. These are material but typically carry less weight than housing delivery unless the economic case is exceptional.

**Heritage benefits** — enabling development that funds the repair or restoration of a heritage asset at risk. This is given significant weight where the asset is on the Heritage at Risk Register or in demonstrable need of investment.

**Community benefits** — public open space, community facilities, improved access, and other benefits that serve the wider community.

The critical point is that the benefits must be **public** benefits, not private ones. A developer's profit is not a public benefit. Increased land value is not a public benefit. The benefits must accrue to the community or the public interest.

The heritage framework is demanding but navigable. Our analysis of successful schemes in heritage-sensitive locations identifies several practical principles:

**Commission a Heritage Statement early.** The heritage assessment should inform the design, not be retrofitted to justify it. Schemes designed with heritage in mind from the outset are far more likely to succeed.

**Be honest about harm.** Applicants who claim "no harm" when harm clearly exists lose credibility with officers and inspectors. It is far better to identify the harm honestly, place it on the spectrum, and then demonstrate that the public benefits outweigh it.

**Articulate public benefits clearly.** The balancing exercise requires benefits on the other side of the scale. If you do not articulate them, the officer has nothing to weigh against the harm.

**Engage with the conservation officer.** Conservation officers provide specialist advice to case officers on heritage matters. Early engagement can identify concerns before they become reasons for refusal.

Heritage planning is not a barrier to development — it is a framework for ensuring that development respects the historic environment. Understanding the case law, applying the correct framework, and presenting honest evidence gives applicants the best chance of navigating it successfully.