Development affecting listed buildings, conservation areas, scheduled monuments, and their settings is subject to some of the strongest protections in the planning system. Understanding the heritage harm tests is essential to preparing an effective objection.
Heritage protection in the planning system is underpinned by statute, not just policy. The Planning (Listed Buildings and Conservation Areas) Act 1990 imposes specific legal duties on decision-makers that go beyond the weight given to ordinary planning policies.
Section 66 of the Act requires that, when considering whether to grant planning permission for development which affects a listed building or its setting, the decision-maker shall have special regard to the desirability of preserving the building or its setting or any features of special architectural or historic interest which it possesses. This is not a discretionary consideration — it is a statutory obligation. Case law has established that this duty requires the decision-maker to give considerable importance and weight to the desirability of preservation, creating a strong presumption against granting permission for development that would cause harm.
Section 72 imposes a parallel duty in respect of conservation areas. It requires that special attention shall be paid to the desirability of preserving or enhancing the character or appearance of a conservation area when exercising planning functions. Again, this is a mandatory duty. A decision that fails to demonstrate proper engagement with this duty is vulnerable to legal challenge.
These statutory duties sit above NPPF policy. Even where an officer or committee concludes that harm is less than substantial and that public benefits outweigh it, they must still demonstrate that they have discharged their duty under Sections 66 and 72. This is a powerful tool for objectors: if a committee report or delegated officer report fails to reference or properly apply these duties, the decision itself may be flawed.
Chapter 16 of the National Planning Policy Framework (NPPF 2024) sets out the policy framework for conserving and enhancing the historic environment. It establishes a structured approach to assessing harm to heritage assets and provides the tests against which planning applications must be evaluated.
The NPPF requires applicants to describe the significance of any heritage assets affected by a proposal, including any contribution made by their setting. The level of detail should be proportionate to the asset's importance and sufficient to understand the potential impact of the proposal on its significance. Where an applicant fails to provide an adequate heritage assessment, objectors can argue that the local planning authority does not have sufficient information to determine the application.
The key concept is that harm to heritage significance must be identified, quantified, and justified. Applicants frequently understate harm or fail to engage with it adequately in their Design and Access Statements or Heritage Statements. A well-prepared objection challenges this characterisation directly.
The distinction between less than substantial harm and substantial harm is one of the most important concepts in heritage planning, and one that is frequently misunderstood — sometimes deliberately so by applicants seeking to minimise the significance of harm.
Substantial harm is a high bar. It involves serious harm to or loss of the significance of a heritage asset. It does not require total destruction — a development that would fundamentally alter the character of a listed building, obscure its principal elevation, or sever its historic relationship with its landscape could amount to substantial harm even if the building itself remains standing. Where substantial harm is identified, the NPPF requires the local planning authority to refuse consent unless it can be demonstrated that the harm is necessary to achieve substantial public benefits that outweigh that harm, or all of a series of stringent alternative tests are met.
Less than substantial harm covers a broad spectrum, from minor and negligible impact at one end to harm that falls just short of the substantial threshold at the other. It is not, as applicants sometimes imply, a finding that harm is insignificant. The Court of Appeal in Palmer v Herefordshire Council [2016] confirmed that even within the less than substantial category, harm must be given considerable importance and weight. The balancing exercise required by the NPPF does not start from a neutral position — there is an in-built presumption in favour of preservation derived from the statutory duty.
Objectors should be wary of heritage assessments that conclude "less than substantial harm" and then treat that conclusion as though it were a green light for approval. The degree of harm within the less than substantial range matters enormously. Harm at the higher end of less than substantial requires commensurately greater public benefits to outweigh it.
Where less than substantial harm is identified, the NPPF requires the decision-maker to weigh that harm against the public benefits of the proposal. This is sometimes called the "paragraph 208 balance" (referring to the relevant paragraph in the 2024 NPPF).
The balancing exercise is not a simple cost-benefit analysis. Heritage harm carries significant weight by virtue of the statutory duty, and the benefits relied upon must be genuinely public rather than private. Common arguments that applicants make — such as the economic benefit of construction employment, the provision of a single additional dwelling, or the personal circumstances of the applicant — rarely constitute public benefits sufficient to outweigh identified heritage harm.
Genuine public benefits might include the restoration of a heritage asset at risk, the provision of significant affordable housing, essential community infrastructure, or the removal of an existing harmful structure. For an objector, the task is twofold: first, establish the nature and degree of heritage harm; second, scrutinise the claimed public benefits and challenge those that are overstated, speculative, or essentially private in nature.
It is also important to consider whether there are alternative designs or approaches that could deliver the same benefits with less harm. Where an applicant has failed to consider alternatives, this weakens their case that the proposed level of harm is necessary or justified.
Development within or affecting the setting of a conservation area must preserve or enhance the character or appearance of the area. This is the statutory duty under Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990, and it applies to the setting as well as the area itself. An objection that demonstrates a clear failure to preserve or enhance — through harm to the established scale, materials, roofscape, boundary treatments, or important views — engages a strong statutory protection.
Most local planning authorities have adopted Conservation Area Character Appraisals for their conservation areas. These documents identify the special qualities that justify the area's designation: the prevailing building heights, characteristic materials, historic plot widths, important views and vistas, key unlisted buildings that make a positive contribution, significant trees and green spaces, and boundary treatments. They often include maps showing the relative contribution of individual buildings and spaces.
For objectors, a Conservation Area Appraisal is an invaluable resource. If the appraisal identifies a particular feature as making a positive contribution to the conservation area — for example, a gap between buildings that provides an important view, or a mature garden that contributes to the area's green character — and a planning application proposes to remove or harm that feature, the objector has the local authority's own evidence base to support their argument. Decision-makers find it very difficult to approve development that conflicts directly with findings in their own adopted appraisals.
Where no appraisal exists, objectors can still describe the character and appearance of the conservation area through their own analysis, photographs, and reference to the original designation documentation.
The concept of "setting" is one of the most important — and most frequently contested — in heritage planning. Setting is defined in the NPPF glossary as the surroundings in which a heritage asset is experienced. Its extent is not fixed and may change as the asset and its surroundings evolve. Elements of a setting may make a positive or negative contribution to the significance of the asset, may affect the ability to appreciate that significance, or may be neutral.
Crucially, the setting of a listed building or other heritage asset is not limited to its immediate curtilage or to land within the same ownership. It extends to the wider area from which the asset is experienced and understood. A new development on the opposite side of a road, at the end of a significant view, or on land historically associated with a listed building can all affect the asset's setting even though they do not physically adjoin it.
Historic England's guidance document The Setting of Heritage Assets (GPA3) sets out a staged approach to assessing setting: identifying which heritage assets might be affected; assessing whether and how the setting contributes to the asset's significance; assessing the effect of the proposed development on that significance; and exploring ways to maximise enhancement and avoid or minimise harm. Objectors can use this methodology to structure their arguments and to highlight where an applicant's heritage assessment has failed to follow the established approach.
Scheduled monuments are nationally important archaeological sites and monuments that are protected under the Ancient Monuments and Archaeological Areas Act 1979. They benefit from the highest level of heritage protection in the planning system. Any works to a scheduled monument require Scheduled Monument Consent from the Secretary of State, entirely separate from the planning permission process.
Development affecting the setting of a scheduled monument is assessed under the same NPPF heritage framework as other designated heritage assets, but the NPPF makes clear that substantial harm to or loss of scheduled monuments should be wholly exceptional. In practice, this means that planning applications affecting the setting of a scheduled monument face an extremely high bar for approval. Objectors dealing with development near scheduled monuments should emphasise the asset's national importance and the exceptional test that applies.
Many local planning authorities maintain a local list of buildings and structures that, while not meeting the criteria for statutory listing by Historic England, are considered to be of local heritage significance. These are sometimes referred to as "locally listed buildings" or "non-designated heritage assets."
Locally listed buildings do not benefit from the same statutory protections as statutorily listed buildings — Sections 66 and 72 of the 1990 Act do not apply to them. However, they are recognised as non-designated heritage assets under the NPPF, and the Framework requires that the effect of an application on the significance of a non-designated heritage asset should be taken into account in determining the application. A balanced judgement is required, having regard to the scale of any harm or loss and the significance of the heritage asset.
For objectors, locally listed buildings remain a material planning consideration. Where a local plan policy specifically protects locally listed buildings — and many do — there is a clear policy hook on which to base an objection. The fact that a building appears on the local list is evidence that the local authority itself considers it to have heritage value, and this should be reflected in the determination of any application that would affect it.
The setting of a listed building is not limited to its immediate curtilage — it extends to the wider area within which the building is experienced and understood. Development that would harm the setting of a listed building, even at some distance, engages the heritage harm tests in the NPPF. The concept of significance encompasses not just the fabric of the building but its contribution to the landscape, townscape, or historic environment within which it sits.
Registered parks and gardens of special historic interest are designated heritage assets. Development within or affecting their setting must demonstrate that it would not harm their significance. These landscapes are often associated with listed buildings and their protection frequently reinforces heritage objection arguments made on listed building setting grounds.
Heritage objections require a precise and methodical approach. At Planning Voice, our Chartered Town Planners follow a structured process designed to identify every relevant heritage consideration and present it in the language that decision-makers respond to.
We begin by identifying all heritage assets that could be affected by a proposal — not just those immediately adjacent to the site, but those whose setting may be impacted. We check the National Heritage List for England (or the equivalent registers in Wales, Scotland, and Northern Ireland), review any Conservation Area Appraisal or Management Plan, and examine the local authority's local list. We also review Historic Environment Record data where relevant to identify undesignated archaeological interest.
We then assess the significance of each affected asset and articulate how the proposal would harm that significance. We apply the NPPF harm tests rigorously, identifying whether harm would be substantial or less than substantial, and at what point on the spectrum. Where the applicant has submitted a heritage assessment, we scrutinise its methodology and conclusions, challenging any understatement of harm or overstatement of public benefits.
Our objection letters directly reference the statutory duties under Sections 66 and 72, the relevant NPPF paragraphs, local plan heritage policies, and any applicable Conservation Area Appraisal findings. We present the case in a way that makes it straightforward for the case officer to identify the heritage policy conflict and recommend refusal — or for a planning inspector to dismiss an appeal.
You can see examples of this approach in our heritage-related case studies, including our work on the Grade II* listed setting objection at Calcot Park, the conservation area refusal at Fyfield, and the withdrawn garage extensions in Gamston Conservation Area.
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