Appeal 3320962

The appeal is dismissed.

The site lies within the Green Belt. Therefore, the main issues are: • Whether the proposal amounts to inappropriate development in the Green Belt; • The effect on the openness of the Green Belt and the purposes of including land within it; • The effect of the proposal on the character and appearance of the area; • If the development is inappropriate, whether any 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 it.

Paragraph 149 of the National Planning Policy Framework (September 2023) (the Framework) states that the construction of new buildings within the Green Belt is inappropriate development but lists certain forms of development which are not regarded as inappropriate. This includes 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.

Policy DM18(a) of the Elmbridge Local Plan Development Management Plan (April 2016) (the DMP) repeats the test of the Framework, adding that support will be given to proposals that do not have a materially greater impact on the openness of the Green Belt, in particular where certain criteria are met, including that they are well designed, do not materially increase the overall height of the building and do not result in an increase beyond 25% in volume and 25% in footprint.

The appeal dwelling has been extended through a rear single storey extension and a hip-to-gable roof extension with a rear dormer window. The proposed extension would extend out from the dormer over the single storey extension, creating an L-shape to the first floor level. The parties agree that the extension would not add to the footprint of the dwelling but would result in the overall volume being 36% greater than that of the original building.

The Framework does not define ‘disproportionate,’ but the cumulative increase in volume would exceed the 25% limit of Policy DM18. The policy as worded gives clear support to proposals achieving the three criteria, but it does not explicitly resist any proposal exceeding the 25% threshold. In my view, a degree of judgement is required given the nature of buildings will differ and what may be disproportionate in one case may not in another.

The proposal would not result in the footprint or the overall height of the dwelling increasing, but at 36%, the increase would exceed the 25% limit of Policy DM18. I do not regard this as a significant increase, in and of itself; however, the extension would create a two-storey structure to the rear which is not characteristic of the immediate surroundings and would alter the overall scale and form of the dwelling at the rear from a chalet bungalow to a two-storey dwelling. The proposal would appear excessive in size relative to the original building and surrounding development, contrary to the first criterion of Policy DM18(a).

In reaching a view, I note reference by the appellants to other developments in the Green Belt where significantly larger increases in volume have purportedly been permitted by the Council. I do not have the full particulars of these cases before me and cannot be certain that the specific circumstances are comparable to this proposal. Therefore, these examples attract limited weight and do not alter my assessment of this scheme, which I have considered on its specific planning merits.

For these reasons, I conclude that the proposal would result in disproportionate additions over and above the size of the original building and the proposal would amount to inappropriate development in the Green Belt, in conflict with Policy DM18 of the DMP and the approach of the Framework.

The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence. Openness in terms of the Green Belt has a spatial aspect and a visual aspect.

The principal change would be the additional volume at first floor level to the rear. In the context of the Green Belt, the degree of visibility of the extension would not be widespread, but rather concentrated to the immediate neighbouring dwellings within an established area of residential development. The scale of the extension, in absolute terms, would also be limited.

Overall, I conclude that the proposal would have a limited adverse effect on openness. Having regard to its position and form, the proposal would not result in a material encroachment of development into the countryside and would not impact on this or any other Green Belt purpose.

The appeal dwelling has been extended at the rear through a full width ground floor extension and a large rear dormer. Many neighbouring dwellings have been similarly extended at the ground floor, with a smaller number of rear dormer extensions. Although there is some variety to the size and design of neighbouring extensions, they are consistent in generally maintaining separation between the ground floor and roof level elements, such that the eaves and roofscapes remain legible across the whole row of dwellings on this side of the cul-de-sac.

The proposed flat-roofed, first floor addition would join the existing ground floor and dormer extensions together in an uncharacteristic, hybrid extension that would not reflect the established pattern of development. The size and shape of the extension would overwhelm the dwelling by wrapping up and over the original rear elevation and roof slope, significantly eroding its modest, original bungalow scale and form. The proposal would conflict with the guidance of the Design and Character Supplementary Planning Document Companion Guide: [name] (the CGHE) in a number of respects, including the use of a flat roof extension on a pitched roof dwelling and extending above the eaves level into the roof space. This in turn would erode the eaves line and dominate the roof slope, contrary to the GCHE.

Although there is a staggered building line, with the pairs at Nos 1 and 2 and 5 and 6 standing slightly rearward of the pair at Nos 3 and 4, the prominent, two storey height and bulky shape of the extension would project significantly above neighbouring extensions and site boundaries and form an aberrant feature in views from the gardens of adjacent dwellings and from dwellings to the rear on [address].

For these reasons, I conclude that the proposed extension would fail to represent good design as sought by the Framework and would significantly harm the character and appearance of the area, contrary to Policy CS17 of the [name] (July 2011) (the CS) and Policy DM2 of the DMP, which together require development to deliver high quality design based on an understanding of local character, and the character of the host building in the case of extensions. The proposal would also conflict with the guidance of the CGHE.

The appellants refer to the possibility of larger extensions being constructed under permitted development (PD). Potential volumes for roof, side and rear extensions are set out, but each of these is subject to various conditions and limitations which mean that the fullest permitted volume is often not achievable. Having observed the extent of existing extensions and the available space within the curtilage, I am doubtful that the roof and side extensions described by the appellant could practically be achieved.

Moreover, of the examples given a 6m single storey rear extension, if achievable through the prior approval process, would not be as visible from beyond the site as the two-storey proposal. This would also be the case for an outbuilding which is effectively limited to a single storey height under PD. As such, I am not persuaded that the potential works put forward would have a more harmful effect on the character and appearance of the area in comparison to the appeal scheme.

Therefore, in the absence of substantive evidence, such as drawings or a lawful development certificate, I am not persuaded that there are realistic fall-back positions in terms of development under PD that merit positive weight towards granting the appeal proposal.

The appellants have advanced personal circumstances in support of the proposal, including the need for additional living space and the difficulty in finding larger properties in the area. I empathise with the appellants’ situation, but these are not unique circumstances. Moreover, they are ultimately private interests rather than public benefits, and so are matters which attract limited weight in the planning balance.

The proposal would cause harm to the Green Belt by way of inappropriateness and a limited loss of openness, to which I afford substantial weight in accordance with the Framework, which adds that development should not be approved unless the harm to the Green Belt, and any other harm, is clearly outweighed by other considerations. In this case, I have also found significant harm to the character and appearance of the area.

For the reasons set out above, I give only limited weight to the material considerations in support of the proposal and conclude that, taken together, they do not clearly outweigh the harm the scheme would cause. Consequently, there are not the very special circumstances necessary to justify inappropriate development in the Green Belt.

The proposal would result in conflict with the development plan, taken as a whole. Material considerations in this case, in particular the Framework, do not indicate that permission should nevertheless be forthcoming despite this conflict.

Therefore, I conclude that the appeal should be dismissed.