Appeal 3280384

Appeal A is dismissed.

Appeal B is dismissed.

As set out above there are two appeals on this site. They differ only in the detail of the design of the proposed development. I have considered each proposal on its individual merits. However, to avoid duplication I have dealt with the two schemes together, except where otherwise indicated. Appeal Decisions APP/G2245/D/21/3280384 and APP/G2245/D/21/3284104

The main issues are: • whether the proposed development would be inappropriate development in the Green Belt, having regard to the National Planning Policy Framework (the Framework) and any relevant development plan policies; • if the proposed development is inappropriate, the effect of the proposed development on the openness of the Green Belt; and • whether the 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 proposed development.

The appeal site comprises a two-storey semi-detached property positioned within a reasonably large plot. Similar properties exist within the surrounding area. The property has been extended previously in the form of a rear two-storey extension.

National Green Belt policy in the Framework sets out that inappropriate development is, by definition, harmful to the Green Belt and should not be approved ‘except in very special circumstances.’ There are, however, certain exceptions. One of those, at paragraph 149, is the extension or alteration of a building, provided it does not result in disproportionate additions over and above the size of the original building. Policy GB1 of the Sevenoaks District Council Allocations and Development Management Plan (LP, 2015) broadly conforms to the general thrust of national Green Belt policy, which in summary supports the limited extension of existing dwellings provided the proposed volume is proportional to the original dwelling.

The Framework does not provide a definition of ‘disproportionate additions.’ However, LP Policy GB1 sets out that the design of extensions should be subservient to the original dwelling and not materially harm the openness of the Green Belt through excessive scale, bulk or visual intrusion. In addition, LP Policy GB1 specifies that the total floor space proposed, together with any previous extensions or alterations, should not result in an increase of more than 50% above the floorspace of the original dwelling. In my view, such a metric may only realistically be an approximation for disproportionality. This is because of the absence of such a metric in the Framework and given that proportionality is inherently context specific.

The Council indicates that the proposed development in its original form had a floor area of approximately 117.8sqm. It indicates that previous extensions together with the current proposals would amount to an increase in floorspace of 95.9sqm in the case of Appeal A and 99.5sqm in the case of Appeal B. In both cases, the Council estimates that the combined extensions would result in an increase in floorspace which exceeds 50% of the original dwelling.

The appellant, on the other hand, estimates that the total of existing and proposed extensions would not exceed 50% of the size of the original dwelling. The appellant takes into account the area of two outbuildings within 5 metres Appeal Decisions APP/G2245/D/21/3280384 and APP/G2245/D/21/3284104 of the main dwelling in Appeal A and considers these to be original. In Appeal B, the appellant takes in account only one outbuilding which is also deemed to be original.

Whilst these arguments are acknowledged, there is no clear evidence to confirm that the single outbuilding I observed on site is original. It appears more modern than the dwelling. From the information before me, it is highly likely that the outbuilding is not original. It would therefore need to be considered as additional floorspace relative to the original dwelling. I am uncertain as to the circumstances of the second outbuilding illustrated in Appeal A as this did not exist at the time of my site visit and is not apparent on any other submitted plans. I therefore do not take this building into account.

On the basis of the existing outbuilding not being original, I conclude the overall increase in floorspace would be in excess of a 50% increase on the original dwelling. Even taking into account the net effect of removing that outbuilding, as proposed in Appeal B, the overall increase in floorspace would be in excess of the 50% figure.

Notwithstanding the above, floorspace is not the only possible measure of proportionality. Even were the combined floorspace figure of existing and proposed additions to the original property below 50% of its original floorspace, I do not consider the alterations to be subservient, as required by LP Policy GB1. In particular, the scale and massing of the proposed roof profile would be large, increasing the volume of the existing dwelling substantially. Moreover, the roof ridge and eaves levels would be in line with those of the main dwelling, visually confusing its original design and form. Consequently, the proposed developments would fail to appear as a subservient addition to the original building.

For the above reasons, the proposed developments would be inappropriate development in the Green Belt which is, by definition, harmful. The proposed developments would therefore conflict with the relevant provisions of LP Policy GB1, which in summary seeks to limit extensions to dwellings in the Green Belt. This is in a similar vein to the objectives of the Framework insofar as development in the Green Belt is concerned.

The Framework indicates that openness is an essential characteristic of the Green Belt, and a fundamental aim of Green Belt policy is to keep land permanently open. The openness of the Green Belt has both a physical and visual dimension. ‘Open’ can mean the absence of development in spatial terms, and it follows that openness can be harmed even when development is not readily visible from the public realm.

Notwithstanding the existence of other properties near the appeal site, intervening boundary features and landscaping across the site, the appeal property is visible from the adjacent highway and neighbouring properties. Nevertheless, the openness of the Green Belt is readily apparent beyond the appeal site.

[name] accept that the proposed developments would form an extension to the dwelling which has been designed with some sensitivity to siting, prevailing building forms, materials and detailing, they would nonetheless result in built Appeal Decisions APP/G2245/D/21/3280384 and APP/G2245/D/21/3284104 volume and massing where this does not presently exist. The additional bulk of the dwelling as a result of the proposed developments would inevitably lead to a loss of openness, both physically and visually. Accordingly, the proposed development would cause harm to the openness of the Green Belt. This factor weighs against the proposal.

I note the comments made by the appellant in respect of landscaping, views and the lack of harm in respect of character and appearance. However, neither the retained nor any proposed landscaping would mitigate the loss of openness or outweigh the harm in that respect. Moreover, a lack of harm or absence of harm is a neutral factor, which does not support the proposals. I therefore award these considerations limited weight.

The proposed developments would be inappropriate development in the terms set out by the Framework and would result in harm to the openness to the Green Belt. The Framework requires that substantial weight should be given to any harm to the Green Belt. I have determined that the other considerations have little weight.

The harm identified would not be outweighed by the other considerations and, therefore, the very special circumstances necessary to justify the proposed developments do not exist. Both schemes are therefore contrary to the relevant provisions of the Framework and the development plan as a whole. Consequently, the appeals are dismissed.