Appeal 3309173

The appeal is dismissed.

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

The Framework establishes that the construction of new buildings in the Green Belt should be regarded as inappropriate, subject to a number of exceptions as set out in paragraph 149. Criterion c) of paragraph 149 is the most pertinent to this appeal, which applies to 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 49 of the Bromley Local Plan (BLP) adopted January 2019 provides that extensions or alterations to buildings in the Green Belt will not be permitted where, they would be disproportionate to the original building. In this regard the policy is consistent with the Framework.

Neither the Framework or the BLP provide a definition of ‘disproportionate additions’ and therefore an assessment of whether a proposal would amount to a disproportionate addition is a matter of planning judgement. The Framework does refer to ‘size’ which incorporates increase in terms of volume and external dimensions, and BLP Policy 51 provides further details on extensions to dwellinghouses within the Green Belt. Policy 51 states that the floor space of the original dwellinghouse should not be increased by 10%, it should not harm the visual amenities of the locality and it should not result in a detrimental change to the form, bulk or character of the original dwellinghouse.

The appeal proposal consists of a front porch, single storey side extension and side dormer extension. The appeal proposal is to create additional living space at ground and first floor level for family accommodation and would provide a similar appearance to the adjoining property. There is no dispute between the parties that there will be an increase in the built form as a result of the appeal proposal. The Council highlights that in terms of size, the appeal scheme would increase the overall floor area by 63m2 which is approximately 74% over the 85m2 of the original building, and this is not disputed by the appellant. The increase in size is clearly in excess of the 10% tolerance under BLP Policy 51.

The increase in footprint at ground floor, and the form and bulk of the scheme particularly at the roof level, through the inclusion of a dormer extension would result in a significant visual change on the host property. However, it is acknowledged that in design terms, the proposal would provide alterations and extensions that are considered to blend in well with the adjoining house and would provide a sympathetic ‘handed’ design to the pair of properties. Nevertheless, when taken in isolation the scheme would further increase the size, mass, bulk and volume of the existing property, to a level that would in my opinion be considered disproportionate to the original building.

Accordingly, the appeal scheme would be inappropriate development in the Green Belt, which, by definition is harmful. The proposal would therefore conflict with the Framework and [name] 49 and 51.

There are spatial and visual aspects to the assessment of the openness of the Green Belt. In spatial terms, the appeal proposal would increase the footprint, volume, form, bulk and character of the existing development. As such, the proposal would have an adverse impact on the openness of the Green Belt in spatial terms.

With regard to the visual aspect, the property is visible from public vantage points along [site address] to the front. The increase in bulk and mass, particularly on the side and at the roof level would be clearly visible from the surrounding area and as such, would intrude upon the openness of it. Nevertheless, the site itself occupies a small ribbon of rural residential developments which include other two storey houses, like the adjoining property, which contrasts with the much less developed open space that surround the area. As such, given the variation I conclude in visual terms, the scheme would have no significant effect on the visual aspect of openness of the Green Belt.

Overall, whilst I find there would be no harm to the visual dimension of the openness of the Green Belt, there would be to the spatial dimension. Therefore, the proposal fails to preserve the openness of the Green Belt.

The appellant refers to a fallback position with regard to permitted development rights and the current legislation on prior approvals in respect to larger extensions. However, I have been provided with no details of an alternative scheme and cannot therefore be sure that there would be a realistic or probable alternative. I therefore give limited weight to this as a fallback option. In any case, each scheme must be considered on its own merits. While consistency in decision making is important, ultimately, what constitutes an exception under Green Belt policy needs to be determined in the light of the specific circumstances and context of each case. I am not therefore persuaded that a permitted development alternative scheme is directly comparable to the proposal before me, and it does not alter my views.

The Council consider the development has no adverse effect on the character and appearance of the area, the amenity of neighbouring occupants or any impact on highway safety. Nonetheless, the absence of harm in these regards does not carry positive weight in favour of the development and these would be neutral factors in the planning balance.

The development plan and the Framework states that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. The Framework goes on to advise that substantial weight should be given to any harm to the Green Belt and that very special circumstances will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations.

It is acknowledged that the proposal is a well-designed addition and would provide a degree of symmetry and coherence between the host dwelling and neighbouring property. Whilst these considerations could provide benefits, they would carry only limited weight in support of the proposal and I conclude that, these do not outweigh the harm the scheme would cause. As such the very special circumstances necessary to justify the development do not exist.

For the reasons set out above, the proposal would conflict with the development plan, when read as a whole and the Framework. Material considerations do not indicate that a decision should be taken other than in accordance with that plan. Having considered all other matters raised, I therefore conclude that the appeal should be dismissed.