Appeal 3324191

The appeal is dismissed.

Since the lodging of the appeal, a revised National Planning Policy Framework (Framework) has been published. This has not raised any new matters which are determinative in this appeal. However, updated paragraph numbers are cited within this decision letter.

The issues are; • whether the proposal would be inappropriate development in the Green Belt having regard to the Framework and any relevant development plan policies, and the effect of the development on the openness of the Green Belt; and • if the proposals would be inappropriate development, 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 development.

The appeal site is within the Green Belt. Framework paragraph 152 guides that inappropriate development is, by definition, harmful to the Green Belt.

Paragraph 154 of the Framework then says that the construction of new buildings should be regarded as inappropriate unless the development would meet one of a number of exceptions. One such exception at 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.

Policy GB2 of the Chiltern District Local Plan Written Statement1 (the Local Plan) indicates that most development in the Green Belt is inappropriate, and provides a general presumption against such development. However, under this policy, permission may be granted for proposals for the limited extension, alteration or replacement of existing dwellings, where they would also comply with Local Plan policy GB13. In Green Belt locations, Local Plan policy GB13 indicates that extensions to dwellings must be subordinate in size and scale to the original dwelling. Where there have been one or more previous extensions, this policy requires that the cumulative effect on the size and scale of the original dwelling be taken into account. These policies are broadly consistent with the parts of the Framework that seek to protect Green Belt land.

What is disproportionate in the context of extensions to buildings in the Green Belt is not defined within Local Plan policies GB2, GB13, or the Framework. Therefore, the assessment of whether the proposal would amount to a disproportionate addition over and above the size of the original building is a matter of planning judgement.

The Council advise that the original dwelling was a modest 2 storey house, with a floorspace of approximately 125sqm. The house has since been subject of a number of extensions, and I understand that cumulatively these have resulted in an increase in floorspace over that of the original building of 163%. I cannot be certain which parts of the existing house formed the original building. However, the additions have significantly increased the size and scale of the original dwelling, such that it is now a substantial detached house, with accommodation over more than 2 levels.

Even accounting for the proposed demolition of the existing conservatory, the evidence suggests that the replacement structures would further increase the floorspace within the dwelling by approximately 9sqm.

Details of the comparative volumes of the parts of the building that are to be removed, and the proposed replacement elements have not been provided. Therefore, I cannot conclude that the proposals would not lead to an increase in the total volume of the building.

The height of the proposed extensions would be variously lower than that of the gable roof of the utility room, which is to be removed. Furthermore, the extensions would not project beyond the outermost walls to the side and rear elevations of the house. However, the proposed gable roof to the rear of the dwelling would be taller and bulkier than the conservatory it would replace. As such, the scale of the building following the implementation of the development would be very similar to that of the existing building. However, and although relatively small, the further increase in floorspace when taken together with the previous extensions, would amount to substantial additions which would not be subordinate to the original dwelling, and which would be disproportionate to it. As such, the proposed development would be inappropriate development in the Green Belt, which would, by definition, be harmful. 1 The Chiltern District Council Chiltern District Local Plan Written Statement – adopted 1997, altered in 2001 and consolidates in 2007 and 2011

Openness is an essential characteristic of the Green Belt. It can be considered both spatially and visually. The scale of the building following the implementation of the proposals would be very similar to that of the current building. Although its footprint would be increased, most of this increase would be within the recess between the utility room and the snug, which is not readily visible from either the lane, or the fields to the rear of the house. Furthermore, the other small additions would not project beyond the outermost walls of the existing building. For these reasons the development would not have a harmful effect on either the visual or the spatial openness of the Green Belt. However, the lack of harm to the openness of the Green Belt is a neutral factor.

Although, in respect of the Green Belt, the proposed development would not cause harm to openness, for the reasons given, it would nevertheless constitute inappropriate development. It would conflict with policies GB2 and GB13 of the Local Plan. It would also conflict with the parts of the Framework and the Chiltern District Council Residential Extensions and Householder Development Supplementary Planning Document – dated 2013, which relate to development in the Green Belt.

Given that Policy CS20 of the Local Plan relates to design and environmental quality, its content does not lead me away from my findings in respect of this

In terms of materials and design detailing, the existing conservatory differs from the remainder of the dwelling. However, even if the conservatory is in poor condition, it is not readily visible from public locations, and does not cause harm to the character or appearance of the area. Notwithstanding this, the replacement of the conservatory with alternative development of a similar scale, which would incorporate external materials that would better match the host dwelling, would lead to small improvements to both the appearance of the house, and to the character and appearance of the area.

Even if the development would improve the internal layout of the house, so that it would better serve the appellants and their family, this is a private benefit to which very limited weight is attributed.

The site is within the Chilterns Area of Outstanding Natural Beauty (AONB). In such locations, paragraph 182 of the Framework guides that great weight should be given to conserving and enhancing landscape and scenic beauty. Given that the proposals would lead to a small improvement to the character and appearance of the area, they would also slightly enhance the scenic beauty of this part of the AONB.

Substantial weight is accorded to the harm that would be caused to the Green Belt.

Even though great weight is given to the small benefit that would result to the AONB, this would not, either individually or in combination with the other identified benefits, outweigh the harm by reason of inappropriateness. Consequently, the very special circumstances necessary to justify the development do not exist.

Overall, and for the reasons given, the proposal conflicts with the development plan when taken as a whole. There are no material considerations, either individually or in combination that outweigh the identified harm and development plan conflict.

I therefore conclude that this appeal should be dismissed.