Appeal 6001314

The appeal is dismissed.

The main issues are: • whether the proposal would preserve or enhance the character or appearance of the Heytesbury Conservation Area (CA); • whether the proposal would preserve the setting of the [name] listed Church of [name] and [name]; and • the effect of the proposed development on the protected Sycamore tree subject to a Tree Preservation Order (TPO).

The CA encompasses the historic core of Heytesbury village, defined by its tightly knit historic buildings, traditional materials and the coherent rhythm of roof forms and gables. [name]. 99 is a later addition, the terrace as a whole contributes positively to this character and forms part of the CA’s significance.

The existing uPVC conservatory, lean-to structures and sectional concrete garage are of limited architectural merit. They are also modest and fairly innocuous structures, and so make a neutral contribution to the significance of the CA.

The proposed extension would introduce a substantial increase in massing at the rear of the terrace. Its depth, height and overall bulk would read as a dominant new volume that competes visually with the historic gable of No. 100. This would erode the established hierarchy of built forms within the terrace and introduce a scale of development that appears overly assertive in this sensitive historic grouping.

The massing impact is exacerbated by the large expanse of blank rendered wall below the line of dormers. This largely unrelieved surface would present as a visually dominant and monolithic element, lacking the articulation, texture or detailing characteristic of buildings within the CA. Its scale and starkness would draw the eye and disrupt the fine-grained character of the terrace and its setting.

The shallow roof pitch, while arising from functional constraints, would produce a contrived roof form that is inconsistent with the traditional pitches that define the CA. Even if finished in clay tiles, the combination of the low pitch and the enlarged mass beneath it would result in a visually awkward and discordant addition.

The absence of clear information on rainwater goods adds further concern. In a conservation area where detailing plays a significant role in the legibility of historic character, the lack of clarity regarding the placement, type and integration of downpipes and gutters creates uncertainty about the final appearance of the extension. Given the scale of the proposed massing, such elements, if installed at disparate angles as suggested, would be prominent and would exacerbate the jarring visual impact of the proposal.

The proposed garage doors, including the roller-door format, would introduce a non-traditional and visually intrusive feature. Their horizontal emphasis and engineered appearance would contrast sharply with the simple, recessive character of outbuildings in this part of the CA and would detract from the surrounding historic context.

Taken as a whole, the proposal would introduce a combination of scale, form and detailing that would diminish the contribution the terrace makes to the CA as a whole.

The proposal would cause harm to the significance of the designated heritage asset. In terms of the National Planning Policy Framework (the Framework), the harm identified to the CA would be less than substantial. The Framework requires development proposals which lead to less than substantial harm to the significance of a designated heritage asset to be weighed against the public benefits of the proposal.

The scheme would deliver a combination of private and public benefits. The improvements to the internal layout and living conditions for the appellant’s family are private benefits, arising from the replacement of outdated and poorly functioning post-war additions with accommodation that better meets modern needs. The works would also address structural shortcomings in the 1960s extension, including settlement and the presence of a heavy chimney, thereby securing the long-term stability and continued viable use of the dwelling. This is a public benefit insofar as it supports the ongoing conservation of a building that contributes to the character of the CA.

Weighing against these benefits is the less than substantial harm to the CA. I acknowledge that the appeal site is not widely visible from the public realm and that the scale of the proposed development is relatively small. Whilst this means that the extent of harm to the designated heritage asset is on the low to moderate end of the spectrum, the Framework establishes that great weight should be given to the conservation of heritage assets irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to their significance. This great weight is reinforced by the statutory duty under Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, which requires considerable importance and weight to be given to the desirability of preserving or enhancing the character or appearance of conservation areas.

When weighing the great weight to be given to the conservation of the designated heritage asset against the collective weight to be attributed to the benefits that would arise from the scheme, the overall benefit would not be sufficient to outweigh the identified harm to the designated heritage asset.

For these reasons, I find that the proposal would fail to preserve or enhance the character and appearance of the CA. Consequently, it conflicts with [name] 57 and 58 of the [name] (2015) (CS), insofar as they require all development to protect, conserve and, where possible, enhance the historic environment, including designated heritage assets, and the conservation and enhancement of the significance of designated heritage assets, their settings and their features of special interest.

The Grade I listed Church of [name] and [name] is a building of exceptional national importance. Its significance derives from its medieval architectural form and craftsmanship, its landmark presence within the village, its spacious, tranquil churchyard and its historic relationship with surrounding buildings, including the former school and terrace. The churchyard forms a key part of the church’s setting, providing open space, mature Yew trees and filtered views toward the terrace.

It has been suggested that the dormers could create a perception of overlooking from the churchyard. The dormers are modest wall dormers, consistent with nearby examples including the [address]. They are positioned at eaves level and would be largely filtered by the mature Yew trees. Their scale and placement would not give rise to a harmful perception of overlooking or erode the tranquil character of the churchyard.

Concerns have been expressed that the extension would be more visible. The Yew trees provide substantial year-round screening and only glimpsed views of the upper extension would be possible. The limited views of the extension from the churchyard mean that the proposal would not form a visually dominant addition to the area around the edge of the churchyard. As such, the ability to appreciate the church’s architectural and historic significance would not be diminished by the proposal.

For these reasons, I find that the proposal would preserve the setting of the [name] listed Church of [name] and [name]. Consequently, it complies with [name] 57 and 58 of the CS in respect of its impact on the listed building.

The Council’s Arboricultural Officer issued a holding objection on the basis that a Tree Constraints Plan, Tree Protection Plan and, if necessary, an [name] should be submitted prior to determination.

Core Policy 57 of the CS requires development to protect important landscape features, including mature trees. Core Policy 58 of the CS requires that development affecting natural heritage assets must demonstrate that harm will be avoided or minimised. Paragraph 187(a) of the Framework requires that planning applications be supported by sufficient information to understand their likely environmental effects.

These policies do not mandate that BS5837-compliant documentation must always be submitted prior to determination. The test is whether the decision maker has sufficient information to assess the likelihood of harm and whether any residual risk can be controlled by condition.

The appellant explains that the Sycamore is located approximately 10–13.5 metres from the proposed garage. A sewage treatment plant was installed in 2024 between the tree and the proposed garage footprint, involving excavation within the garden. The tree remains in good condition, and the Council’s Arboricultural Officer has recently visited the site and agreed to the appellant’s request to pollard the tree.

Based on typical BS5837 calculations, the likely root protection area (RPA) would not extend to the proposed garage foundations. The intervening installation of the sewage treatment plant provides a real-world demonstration of the tree’s resilience to limited ground disturbance in this part of the garden.

The scale of the garage is modest, and the construction methods are unlikely to require deep excavation or heavy machinery within the RPA. Any residual risk can be fully mitigated by conditions requiring a Tree Protection Plan and, if necessary, an [name].

For these reasons, on the evidence before me, and subject to suitable tree protection measures secured by condition, I have no basis to consider the long-term retention of the TPO tree would be in question as a result of the development. Consequently, the proposal does not conflict with [name] 57 and 58 of the CS, insofar as they require the protection of TPO trees as key components of local character, and their conservation where they contribute to the significance or setting of designated heritage assets.

For the reasons given above, the proposal conflicts with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. Accordingly, the appeal should be dismissed.