Appeal 3272905

The appeal is dismissed.

My attention has been drawn to appeal reference APP/J0405/D/20/3264569 which saw the dismissal of a proposal for a part two storey, part single-storey rear and side extension with associated landscaping. As this is the same site and similar proposals to this appeal I have taken this decision into consideration.

The main issues are: • Whether the proposed extension, together with previous extensions added to the dwelling, would constitute ‘inappropriate development’ in the Green Belt; • The effect of the development on the openness within the Green Belt, and • If so, whether there are other considerations which clearly outweigh the harm caused by being inappropriate development so as to amount to very special circumstances.

As set out with the 2020 appeal, the appeal site contains a detached two storey house in an ‘Arts and Crafts’ style which lies on its own to the north of [address] in an area of countryside which forms part of the Chilterns Area of Outstanding Natural Beauty (AONB) and also lies within the Metropolitan Green Belt.

The proposal is for extensions to the existing house which would result in an increase of approximately 60% in volume on the original dwelling.

The development plan includes the Vale of Aylesbury Local Plan (VALP) (adopted in 2021) and the [name] plan, made February

Policy S4 in the VALP relates to development in the Green Belt. It sets out circumstances where small scale development may be appropriate. In this case I would not consider that this is a ‘replacement building’ being proposed as the existing house is to remain. However, policy S4 also sets out that within the Green Belt extensions and alterations to buildings that are not out of proportion with the original building, normally no more than 25-30% volume increase of the original building, may be supported. This is a newly adopted policy that replaces policy RA.18 in the former AVDLP, which was referred to on the Council reason for refusal.

This policy is broadly consistent with paragraph 149 (c) of the National Planning Policy Framework (the Framework) which sets out that the construction of new buildings in the Green Belt is ‘inappropriate development’ unless it is an extension or alteration to a building that does not result in disproportionate additions over and above the size of the original building.

Considering the scale of total extensions (existing and proposed) to the original house, resulting in considerable increases in both floor area and volume, I would not conclude that the additions would be proportionate when considered against the original building size.

The appellant has drawn my attention to other extended properties in the area and also appeal decisions where extensions to dwellings within the Green Belt have been allowed. Indeed, there could be an argument in certain circumstances where a percentage increase in volume is ‘proportionate’ though greater than the 30% maximum set out in policy S4 for example. However, in this case the volume of cumulative extensions to this house would be significantly more than 30% to the extent that I would not conclude that the original dwelling would be proportionately extended. As such, I have considered the proposals on their merit whilst acknowledging that other buildings may differ in what would be regarded as proportionate additions.

The proposal includes demolition of a pool structure and part of a barn to ‘offset’ the extensions proposed (which will be considered in more detail with the planning balance). However, neither the relevant VALP policies or the Framework suggest that offsetting the volume of extensions by demolishing other separate buildings and structures as being appropriate. Indeed, the supporting text to policy S4 explicitly states that when working out volume increase calculations the term ‘original building’ means the house as it was first built or stood on 1 July 1948 excluding sheds and outbuildings (paragraph 3.35).

I conclude that the proposals would be inappropriate development which is, by definition, harmful to the Green Belt. It would also fail to accord with policy S4 in the VALP as it would not meet with any of the small-scale development exceptions.

Openness is an essential characteristic of the Green Belt. The proposed extensions would increase both the footprint and size of the house, which would be at least partially visible, such as from the road to the front, for example. There would therefore be a small loss of openness to this part of the Green Belt, although this would be offset by the proposed demolition works.

As such, there would be no overall loss of openness within the Green Belt. In terms of built volume within the Green Belt there would be some enhancement in openness as a result of the proposed demolition works.

I have found that the proposed development would be inappropriate development which the Framework states is, by definition, harmful to the Green Belt. This harm must be balanced with the other considerations in this case, including the demolition work proposed to offset the loss of openness from the proposed extensions. ‘Very special circumstances’ will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations, as set out in paragraph 148 of the Framework.

As set out above, the proposal would include the demolition of part of the barn and the pool structure. These structures are separate from the dwelling. Whilst the barn is close to the dwelling, the pool structure is a considerable separation distance from the house itself. Whilst the pool structure is within the Green Belt, it has limited visual association with the house given the separation distance. As such, the benefits of demolishing this structure are limited when considered against the harm to the Green Belt due to the disproportionate house extensions proposed.

The barn, however, is much closer to the house and has much more of a visual association. The section of barn to be removed is similar in volume and floor area to the extent of the proposed extensions considered with this appeal. This is a benefit as the demolition of part of the barn would increase openness, and it would also help in offsetting the loss of openness from the house extensions. However, the demolition of part of the barn only goes as far as to approximately counter the loss of openness from the extensions now proposed.

The proposed development would still be a form of inappropriate development and therefore harmful by definition. Offsetting the loss of openness to the extent proposed would not clearly outweigh this harm.

Within the appellant’s documents there is a demonstration of what could be built at this property under permitted development rights and how that would be similar to the volume proposed with this appeal. However, there is no detailed evidence of whether such extensions under permitted development would likely be built and therefore whether this is a realistic fallback position if this appeal were to be dismissed. As such, I give this matter limited weight.

The proposed extensions appear to have been sympathetically designed within this large plot, with there being no harm to the AONB identified by the Council. The proposal would include some demolition of buildings/structures within the Green Belt which is positive from both an openness and landscape perspective. I also note the sustainable aspects with the development proposed.

Whilst noting the positive aspects of the scheme, the proposal would be inappropriate development within the Green Belt due to the cumulative volume of extensions that would add to this house, which is by definition harmful. The proposed demolition works would help maintain openness within the Green Belt, but overall, the benefits do not clearly outweigh the harm so as to amount to very special circumstances. The proposal is therefore in conflict with both the Development Plan and the Framework in this regard.

For the reasons given above I conclude that the appeal should be dismissed.