Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — by David Cliff BA Hons MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 24th March 2026

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE  The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission.  The appeal is made by Mr and Mrs A Whittall against the decision of Tonbridge and Malling Borough Council.  The application Ref is TM/25/01010/PA.  The development proposed is demolition of single storey outbuilding and construction of single storey garden room and secondary entrance to dwelling.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — Trench Farmhouse, Coldharbour Lane, Hildenborough, Kent, TN11 9LE  The appeal is made under section 20 of the Planning (Listed Buildings and Conservation Areas) Act 1990 (as amended) against a refusal to grant listed building consent.  The appeal is made by Mr and Mrs A Whittall against the decision of Tonbridge and Malling Borough Council.  The application Ref is TM/25/01012/PA.  The works proposed are demolition of single storey outbuilding and construction of single storey garden room and secondary entrance to dwelling.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; https://www.gov.uk/planning-inspectorate

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; https://www.gov.uk/planning-inspectorate Appeal Decisions APP/H2265/W/25/3374700, APP/H2265/Y/25/3374702 iii) Whether the proposal would preserve or enhance the character or appearance of the Coldharbour – Hildenborough Conservation Area (‘the Conservation Area’); and iv) Whether any harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations, so as to amount to the very special circumstances required to justify the proposal? Reasons Green Belt 5. Paragraph 154 of the National Planning Policy Framework 2024 (‘the Framework’) explains that development in the Green Belt is inappropriate, one of the exceptions being (paragraph 154 (c)) the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building (the building as it existed on 1 July 1948). 6. The existing dwelling has been previously extended since 1948, with a part two storey/part single storey rear extension constructed which is of considerable size and massing.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; The applicants calculate that, considered cumulatively, the proposals would represent a 61% increase in the footprint of the dwelling over that of the original dwelling, including the existing outbuilding, a 38.7% increase in floorspace and 41% increase in volume. Neither the Framework nor Policy CP3 of the Tonbridge and Malling Borough Core Strategy 2007 (‘the Core Strategy’) set out a numerical threshold for considering what is a disproportionate addition over and above the size of the original building. 7. The proposed development, in addition to the previous extension would represent a very considerable overall addition to the built form and massing of the dwelling and physical loss of openness. Whilst noting the variety of designs for different parts of the extended building, they still materially contribute to the overall size and massing. As well as representing a considerable numerical increase in footprint, floorspace and volume, the existing extension represents a significant projection to the rear. Even noting the existing outbuilding to the side of the dwelling and the extant link side extension, the current proposal would further extend the built spread of the building at the side of the dwelling.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Whilst single storey, it would still represent a substantial extension with its ridge height raising approximately to the eaves level of the two storey part of the existing house. 8. Whilst the existing and proposed extensions are to the rear and side of the building and set back from the front elevation any lack of visual prominence does not materially alter whether or they would cumulatively amount to disproportionate additions in the context of paragraph 154 of the Framework. 9. For the above reasons, the proposed extension considered cumulatively with the previous extension to the dwelling, would amount to a disproportionate addition over and above the size of the original dwelling. It would therefore be inappropriate development in the Green Belt. 10. The proposal would be set back from the front elevation and would not be particularly prominent from public vantage points, although its pitched roof would be partially visible from the road when approaching from the north. Spatially, it would result in an increase in footprint and would be materially larger than the https://www.gov.uk/planning-inspectorate 2

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Appeal Decisions APP/H2265/W/25/3374700, APP/H2265/Y/25/3374702 outbuilding to be removed. Given that the proposal involves an extension to an existing dwellinghouse and is single storey, the effect on openness of the Green Belt would be fairly modest. It would also not be consistent with one of the five purposes of the Green Belt, namely, to assist in safeguarding the countryside from encroachment, again to a modest degree. 11. I have considered the two appeal decisions for extensions to other dwellings in the Green Belt presented by the appellants. I do not have all the details of these cases before me, noting that each case has to be considered on its own merits, I do not find the general approaches taken to be significantly different to that for this appeal. 12. Paragraph 153 of the Framework makes clear that substantial weight is given to any harm to the Green Belt, including harm to its openness. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Very special circumstances will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations. I go on to consider this below. Listed building and Conservation Area 13. The Grade II listed Trench Farmhouse dates from the late 1830’s/early 1840’s. The richly decorated asymmetrical building is of brick with decorative tile hanging above. The building comprises some unusual external detail including deep verges and pierced curly bargeboards, first floor projecting bay with incised diagonal decoration and striking one, two and three-light casement windows. It has been altered and extended over time and at one time comprised two separate dwellings. As noted above, it has been more recently subject to a considerably sized rear extension. 14. It’s special interest, insofar as it relates to this appeal, is primarily associated with the architectural and historic interest of a 19th century farmhouse with later alterations evidencing the historic phasing of the building. 15.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Trench Farmhouse is one of the key buildings within and making a positive contribution towards the character and appearance of the Conservation Area. The significance of the Conservation Area on Coldharbour Lane includes a variety of historic buildings, including those like the appeal property with rick architectural detail, within a rural landscape, evidencing the historic agricultural development and use of the area. This Coldharbour area is in contrast to the more built-up form and character of the Hildenborough part of the Conservation Area evidencing the historic evolution of what was once little more than a hamlet located on the important routes from London to the coast. 16. The proposed extension would sit further forward than the existing outbuilding and would be of a more dominant appearance. The arched entrance would appear as being incongruous with the otherwise ornate architecture of the main house. It would harmfully compete with the primacy of the front elevation of the building, including the existing entranceway to the dwelling, and would upset the overall historic balance, form and layout of the building. 17.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Furthermore, in addition to the existing substantially sized rear extension, the proposal would cumulatively overwhelm the historic core of the building, eroding its https://www.gov.uk/planning-inspectorate 3

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Furthermore, in addition to the existing substantially sized rear extension, the proposal would cumulatively overwhelm the historic core of the building, eroding its https://www.gov.uk/planning-inspectorate 3

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Appeal Decisions APP/H2265/W/25/3374700, APP/H2265/Y/25/3374702 legibility and diminishing the significance of this listed building. The proposed use of high quality materials and the removal of existing features on the side elevation such as drain pipes would not override the harm that would result to the listed building. 18. Despite the proposed extension being set back from the front elevation and noting the existence of some screening along the front boundary, the building is listed for its intrinsic architectural and historic interest and the visibility of the proposed works is not a determining factor in considering whether they would preserve its special interest. 19. For the above reasons, the proposal would fail to preserve or enhance the special interest of the building. 20. In the context of the Conservation Area, the extension, whilst set back from the frontage of the property, could be glimpsed in its immediate context from Coldharbour Lane. Taking account of its harmful relationship with the host building as set out above, it would fail to preserve or enhance the character and appearance of the Conservation Area. Other considerations and planning balance 21.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; The property has the benefit of an extant permission/consent for a link building on the same side of the building as the current proposal. There does not appear to be any impediment to it being implemented if the appeal scheme does not proceed and therefore it is a realistic fall back. Nevertheless, the extant link building extension would be of lesser foot print and massing that the current proposal. It therefore carries little weight as a fall back proposal, as its effects on the Green Belt as well as the special interest of the listed building and the Conservation Area would be less than the appeal proposal. The removal of the existing outbuilding also carries little weight as an ‘other consideration’ given its modest size and massing. 22. Paragraph 212 of the Framework advises that when considering the impact of a proposal on the significance of designated heritage assets, great weight should be given to their conservation. Paragraph 213 goes onto say that any harm to, or loss of significance of a designated heritage asset through its alteration or destruction, or from development within its setting, should require clear and convincing justification.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Given that the proposal is single storey, does not significantly affect the physical historic fabric of the building and is only visible to a limited degree within the Conservation Area, I find the harm, whether considered cumulatively or individually, to be less than substantial in this instance and between the lower and moderate level within the spectrum of less than substantial harm. Nonetheless, this harm carries considerable important and weight. 23. Under such circumstances, paragraph 215 of the Framework advises that this harm should be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use. Whilst enhanced living accommodation would be provided, this would be a private benefit, noting that the existing dwelling already appears to provide a good standing of accommodation. The continued viable use of the building for residential use is not dependent on the proposal, as the building has an ongoing residential use that would not cease in its absence. https://www.gov.uk/planning-inspectorate 4

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; Appeal Decisions APP/H2265/W/25/3374700, APP/H2265/Y/25/3374702 24. There are no public benefits that would outweigh the less than substantial harm to the designated heritage assets. I conclude that the proposal would fail to preserve the special interest of the listed building and would not preserve or enhance the character or appearance of the Conservation Area. 25. Turning to the Green Belt balance, the other considerations identified above, including the extant permission, do not clearly outweigh the harm identified to the Green Belt, listed building and Conservation Area. Consequently, the very special circumstances necessary to justify the development in the Green Belt do not exist. 26. The proposal would therefore be contrary to the heritage, design and Green Belt aims of Policies CP1(3), CP3 and CP24 of the Tonbridge and Malling Borough Core Strategy 2007, Policy SQ1 of the Managing Development of the Environment Development Plan Document 2010, the Framework and the Act. Conclusion 27. The proposed development would be contrary to the development plan and the other material considerations in this case do not suggest that the decision should be taken otherwise than in accordance with the development plan. 28.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — historic interest it possesses; I therefore conclude that the appeals should be dismissed.

Trench Farmhouse, Coldharbour Lane, Hildenborough, Tonbridge, TN11 9LE — Tonbridge and Malling Borough Council — David Cliff INSPECTOR https://www.gov.uk/planning-inspectorate 5