Appeal 3318608

The appeal is dismissed.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

Despite some minor variations, the description of development set out in the application and appeal forms and decision notice are not fundamentally different. I have therefore used the description on the application form since it describes the proposals in sufficient detail.

The main issues are a) whether the proposed development would be inappropriate development in the Green Belt; b) the effect of the proposed development on the openness of the Green Belt; and c) whether the harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations. If so, would this amount to the very special circumstances required to justify the proposal.

The National Planning Policy Framework 2023 (the Framework) sets out, in regard to Green Belts, that their essential characteristics are openness and permanence. There is a general presumption against inappropriate development in the Green Belt unless very special circumstances exist. The construction of new buildings should be regarded as inappropriate, but for certain defined exceptions. These are first set out by Paragraph 149. Specifically, and in regard to the appeal scheme, 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 might not be inappropriate development. This language is mirrored in Policy 49 of the Bromley Local Plan 2019 (LP) and Policy G2 of the London Plan. The term ‘original building’ is defined in the Framework as a building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally.

Policy 51 sets out, amongst other things, that extensions or alterations to dwellings in the Green Belt will only be permitted if the net increase in the floor area over that of the original is no more than 10%, as ascertained by external measurement. Policy 51 further requires that the size, siting, materials and design do not harm visual amenity or the open or rural location of the locality; and that the development does not result in a significant detrimental change in the overall form, bulk or character of the original dwelling.

The Council submit that the proposal would add approximately 62 cubic metres in volume to the original house or 9.8% and that a previously built two-storey extension cumulatively results in a 42% increase on the original dwelling. Whilst the appellant disagrees with the volume figure for the proposals, it is unclear if this final percentage is calculated in volume, area or something else. What is clear is that Policy 51 specifically requires the increase to be worked out from the floor area as ascertained by external measurement. Floor area is two dimensional and is different to floor space, which can mean the sum total of multiple floors taken together. It is patently different to volume. The floor area would therefore be the footprint of the house. As it was originally for the purposes of Green Belt assessment.

Arguably, the proposed development of the roof space would result in no increase in the floor area as ascertained by external measurement. It would be contained almost entirely within the roof space. [name] have also alluded to above I cannot be certain, from a cumulative point of view, whether previous extensions have reached or breached the 10% restriction. That said, and even if the appeal scheme were to comply with one part of Policy 51, I should have regard to the remaining criteria of Policy 51 and the Framework.

Whilst the ridge height would assimilate well to the pattern and rhythm of the adjacent two storey properties (being of similar height), the additional bulk and scale of the hip to gable roof would be disproportionate to the original dwelling, leading to the roof having a more noticeable and imposing impression on the building as a whole. Additionally, the proposed rear box style dormer would utilise almost all the height and width of the rear roof slope. This would not only add further considerable mass and scale to the roof, but also emphasise the top heavy feel to the scheme. Cumulatively, these aspects would result in a significant detrimental change in the form and character of the dwelling. In so being, the design would harm visual amenity.

Turning to the Framework, and since it considers additions which can mean area, floor space and volume, the hip to gable changes and substantial dormer would, when taking into account the totality of the bulk and mass of extensions that have gone before, represent disproportionate additions over and above the size of the original dwelling both quantitively and qualitatively. The scheme would therefore be inappropriate development in the Green Belt, contrary to the Framework and policies 49 and 51 (as a whole) of the LP and Policy G2 of the London Plan. The aims of which I have set out above.

The harm I have found in regard to the design of the scheme would also bring the proposed development into conflict with Policies 6 and 37 of the LP which set out, amongst other things, that all development proposals (extensions to dwellings specifically) will be expected to be of a high standard of design that respects the host dwelling and be compatible with the surrounding area. Policy 6 specifically refers to dormer windows explaining, amongst other things, that they should be of a size and design appropriate to the roofscape.

The Framework indicates that openness is an essential characteristic of the Green Belt with a fundamental aim of Green Belt policy being to prevent urban sprawl and keep land permanently open. There are two aspects to openness. These are spatial and visual. The former being taken to mean the absence of built form.

Whilst the proposals would not involve additional floor area, they would nevertheless include built form (in terms of location and overall size) where it was not before. Whilst the majority thereof being on the rear may limit the visual effect it might have on the openness of the Green Belt, there would be an unavoidable reduction in its spatial aspect. This would be harmful to the Green Belt. This harm would be as well as the inappropriateness of the proposals and further conflict with the Green Belt provisions of the Framework.

The current proposal is for a hip to gable roof extension and as such is materially different to a scheme for a half hip roof extension to the neighbouring property. I therefore attribute this factor little weight. Whilst some rear dormers do exist within the street scene, I cannot be certain under what development plan they were considered nor what material considerations were part of those planning judgements. I also note the disparity in size of the current proposal to existing dormers. I therefore attribute this factor little weight.

The only evidence I have of the Council’s decision in regard to the appeal scheme is the decision letter, which refuses the application. In addition, the time taken to reach that decision is in no way indicative of the outcome and I therefore attribute these factors little weight.

In their reasons for refusal, the Council refer to the ‘visual amenities’ of neighbours which, to my mind, suggests what a given occupier might observe. I have taken a view on the acceptability of the appeal scheme in design terms and thus responded to the Council’s reason for refusal on character and appearance grounds above. However, the delegated officer report expresses substantive concerns over living conditions matters. Suggesting that the occupiers of No 29 will suffer adverse effects of overbearing and loss of light, outlook and privacy. ‘Prospect’ is not quantified.

The properties in the vicinity follow a building line and there is a significant gap between No 29 and the appeal property at first floor and roof level. Consequently, the raise in ridge height and hip to gable would be sufficiently far away and would not lead to being overbearing or harmfully affect light or outlook. Privacy in the rear garden of No 29 is already compromised to a certain extent by the existing first floor windows at No 27. The proposed second floor fenestration would allow further opportunities to overlook neighbours’ gardens; however, this is existing and mutual on both sides. Added to a lack of evidence to the contrary and the lack of objection from No 29, privacy will not be harmfully affected.

Whilst this may lead to some compliance with the development plan and the Framework, this would be a lack of harm and would not weigh in favour of the scheme. It would accordingly be neutral.

Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. There would be further harm to the Green Belt in terms of a reduction in its openness and, whilst linked to an assessment of the design of the scheme in the context of the Green Belt policies of the LP, the proposed development would cause harm to the character and appearance of the area.

I have explored the other considerations raised but given the weight they would attract, set against the substantial weight that should be ascribed to any harm to the Green Belt, makes it evident that they would not be capable of clearly outweighing said harms. The very special circumstances needed to justify the proposals do not therefore exist. This and the conflict with the development plan that would arise from the proposed development, in the absence of any sufficiently weighty material considerations to indicate to the contrary, leads me to recommend the appeal be dismissed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed.