Appeal 3334762

The appeal is allowed and planning permission is granted for the partial demolition of the existing dwelling and erection of a new two-storey rear extension including reforming the roof to provide new bedrooms in the roof space with dormer windows, conversion of the existing garage and infill of the car port to form new garage, new terrace to rear and fenestration alterations at Glenwood, Ightham, Sevenoaks [postcode] in accordance with the terms of the application, reference TM/23/01711/FL, subject to the following

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following drawings: • Site/Block plan as existing (Drawing 8549-PD-003, June 2023) • [name] as existing and Site Location Plan (Drawing 8549-PD-001, June 2023) • Elevations as existing (Drawing 8549-PD-002, June 2023) • Site plan as proposed (Drawing 8549-PD-006, July 2023) • Floor plans as proposed (Drawing 8549-PD-004, July 2023) • Elevations as proposed (Drawing 8549-PD-005, July 2023)

The external materials of the extension hereby permitted shall match those used in the existing dwelling.

Prior to the first occupation of the extension hereby permitted, the existing extension shown to be demolished on drawing nos. 8549-PD- 004, 8549-PD-005 and 8549-PD-006 shall be removed in full, and the land restored to its former condition.

The appeal site lies within the Green Belt, and accordingly I consider that the main issues are: • Whether the proposal would be inappropriate development within the Green Belt having regard to the National Planning Policy Framework (“the Framework”) and any relevant development plan policies, and its effects on the openness of the Green Belt; and • If the development is inappropriate, whether the harm by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations, so as to amount to the very special circumstances necessary to justify the development.

Glenwood is a large detached house set on a substantial plot on the eastern side of [site address] outside the village of Ightham. The proposed development is a rear extension to the house to facilitate the provision of additional rooms on the ground floor and within the roofspace at first floor level, along with the conversion of the existing garage at basement level to provide a further bedroom, and infilling an open-sided car port to create a new garage. An existing single-storey wing at the south-west corner of the dwelling would be demolished.

The appeal site lies within the Metropolitan Green Belt, the Oldbury Conservation Area (“the OCA”), and the Kent Downs National Landscape (“the KDNL”)1 – I return to the OCA and the KDNL in the “other matters” section below. Policy CP3 of the 2007 Tonbridge and [name] (“the TMCS”) states that “national Green Belt policy will be applied generally to the west of the A228”, an area which includes the appeal site. The Government attaches great importance to Green Belts and the fundamental aim of national Green Belt policy, as set out in the Framework, is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence.

Paragraph 152 of the Framework states that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very specific circumstances, while Paragraph 154 indicates that, other than for listed exceptions, the construction of new buildings in the Green Belt should be regarded as inappropriate. One exception, provided for by Paragraph 154 c), is “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 Framework does not specify either in relative or absolute terms what might be considered a disproportionate addition, nor have I been made aware of any local policy or guidance which does so. It is therefore a matter of planning judgement depending on the circumstances of each case. The “original building” is defined in the Framework’s glossary (Annex 2) as being the 1 Previously National Landscapes were known as Areas of Outstanding Natural Beauty, and the previous title still appears in legislation and guidance. “building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally”.

The “original building” in this case is the south-western part of the house which would be demolished under this appeal scheme. It was extended following grants of planning permission in 1986 and 2015 (LPA refs: TM/86/11649/FUL and TM/15/02083/FL respectively). By the Council’s calculation, the original dwelling had a floor area of 125.5m2; by the appellants’ calculation, the building currently has a floor area of 354m 2, which would be increased to around 369m2 under the appeal scheme. I have not been provided with volumetric calculations for house either as originally built or as it now stands; however, the appellants suggest that as a result of demolitions the appeal scheme would add only around 12m 3 net to the existing dwelling.

The two main parties have used slightly different approaches in getting from the pre-1986 floorspace to that which would follow the appeal scheme floorspace, and there are therefore some minor discrepancies between their calculations. Notwithstanding this, there is no doubt that the development would increase the floor area of the building further, and the main parties appear to be in broad agreement that it would lead to the floorspace of the original pre-1986 building having been more or less tripled in size. There would also be a small increase in built volume on the site compared to the current position. While the greatest part of the increases to floorspace and volume have taken place under earlier permissions, it is clear that Glenwood has already been substantially enlarged. However, there are other factors beyond these calculations which it is important to take into account when assessing whether the appeal scheme would result in “disproportionate additions” in the Framework’s terms.

The proposed demolition of the south-western corner of the existing house means that the built footprint of the dwelling would be reduced from around 238m2 to approximately 202m2, increasing the area of garden within the site. Looking beyond floorspace, footprint or volume measurements, the new rooms at first floor level would be within a crown roof form, and the existing ridge height would not be raised. Other aspects of the scheme would have a positive effect on the building’s appearance and its visual impact on the green belt; at present, the south-western wing gives the property a rather rambling and somewhat disjointed appearance, and the demolition of this part of the house would square off the building. Overall, although the appeal scheme would lead to a further increase in both the floorspace and built volume of a building which has already been substantially enlarged, it would also result in the appeal property taking on a neater, more compact, better-proportioned and less sprawling appearance.

Taking all of these points together, I conclude that the proposed development would not result in disproportionate additions and would fall within the exception set out in Paragraph 154 c) of the Framework. It would also comply with Policy CP3 of the TMCS in this regard. I therefore conclude that the proposal would not be inappropriate development in the Green Belt.

[name] have found that the proposed development would not be inappropriate development in the Green Belt in the terms set out in Paragraph 154 of the Framework, it is not necessary for me to assess its effects on the openness of the Green Belt, or whether there are very special circumstances which might otherwise justify the proposal.

As the appeal site is within the [name] have a statutory duty to pay special attention to the desirability of preserving or enhancing the character or appearance of the conservation area. The appeal site is also within the KDNL; the Framework emphasises at Paragraph 182 the importance of conserving and enhancing the landscape and scenic beauty of Areas of Outstanding Natural Beauty, and there is a statutory duty on “relevant authorities” to seek to further the purpose of conserving and enhancing the natural beauty of those areas2.

I note that, other than in terms of its size in relation to Green Belt policy, the Council did not raise any more specific concerns about the design of the proposed extension, or its effects on the character and appearance of either the host building or the wider area. In relation to the OCA specifically it was satisfied that the character and appearance of the conservation area would be preserved. It was also satisfied that there would be no harm to the character or appearance of the KDNL or its landscapes. None of the evidence before me leads me to disagree with these assessments; I am satisfied that the character and appearance of the OCA would be preserved, and the landscape and scenic beauty of the KDNL would be conserved.

I have considered the conditions suggested by the Council in the light of the Framework and advice in the Planning Practice Guidance. Where necessary I have altered the ordering and proposed wording in the interests of clarity and effectiveness. As well as the standard time limit condition (1) I have specified the approved plans to provide certainty (2), and imposed a condition requiring materials to match the existing building so as to protect the character and appearance of the area (3).

It will be apparent from my reasoning above that my conclusion that the appeal scheme would not be inappropriate development in Green Belt terms is highly contingent on the demolition of the south-west wing of the existing dwelling. As such, a condition requiring the demolition to be completed before the permitted extension can be occupied is necessary to protect the Green Belt in line with national policy (4).

Paragraph 54 of the Framework indicates that “planning conditions should not be used to restrict national permitted development rights unless there is clear justification to do so”. I have not imposed the suggested condition removing certain permitted development rights 3, which the Council considered would be necessary to protect Green Belt openness and to prevent the construction of extensions or outbuildings which “would be contrary to the spirit of this planning permission”. Given my conclusions in respect of the overall impact of the appeal scheme, the site’s location within the Green Belt and KDNL does not itself provide a clear justification for removing the permitted development 2 Section 85 of the Countryside and Rights of Way Act 2000, as amended on 26 December 2023 by section 245 of the Levelling-up and Regeneration Act 2023 3 Relating to [name], B and E of Part 1 of Schedule 2 of the Town and Country Planning (General Permitted Development) Order 2015 (as amended) rights from which the property currently benefits; while I recognise the Council’s responsibility to protect the Green Belt and KDNL there is no indication in the Framework that permitted development rights should be restricted as a matter of course. The circumstances of this case are such that a condition along the lines proposed would be neither necessary nor reasonable, and in my view it would fail the tests of Paragraph 56 of the Framework.

The proposed extension would not be inappropriate development in the Green Belt, and no other harm has been identified which would justify refusing planning permission. The appeal is therefore allowed.