Appeal 3324299

The appeal is dismissed.

While reason for refusal 1 refers to character, the Council has concluded in its delegated report that the proposal would not harm the character and appearance of the area. As a result, the main issues are: i) 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; ii) the effect of the proposed development on the openness of the Green Belt; and, iii) if the proposal is inappropriate development, would the harm by reason of inappropriateness, and any other harm, be clearly outweighed by other considerations as to amount to the very special circumstances required to justify the development.

The appeal site lies within the Green Belt and consists of a detached chalet-style dwelling, which has a narrow rear garden. The existing dwelling and car parking area currently dominate the front part of the plot. The property contains accommodation in the roof and has first floor windows in the gables on the front and rear elevations and dormers on both roof slopes. To the rear of the property is a single-storey conservatory and an area of decking. The area is predominantly residential in character, with the exception of a small village hall, which lies to the south-west of the appeal site. Topographically, the land falls away to the rear of the appeal site, where there are views available over the surrounding countryside.

The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. Substantial weight should be given to any harm, and 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.

The construction of new buildings is deemed to be inappropriate development within the Green Belt. However, there are a number of exceptions to this, including paragraph 149 c) of the National Planning Policy Framework (the Framework), which relates to the extension or alteration of a building provided that it does not result in a disproportionate addition over and above the size of the original building. This is consistent with Policy G2 of the London Plan 2021, which I am advised supersedes Policy 7.16 of the London Plan 2016, which the Council refers to in its reason for refusal.

Policy 51 of the Bromley Local Plan (the Local Plan) January 2019 provides criteria for assessing proportionality. It states that extensions to a dwelling within the Green Belt will only be permitted where among other things, the net increase in floor area over that of the original dwellinghouse is no more than 10%. Policy 51 defines the ‘original dwelling’ to mean as it existed on 1 July 1948, or, if constructed after 1 July 1948, as it was built originally, which is consistent with the definition given in Annex 2 of the Framework.

The supporting text to Policy 51 explains that the objective of this policy is to ensure that there is no incremental harm to the Green Belt by excessive extensions to dwellings, which may jeopardise the open nature of the Green Belt. This is broadly consistent with the aims of the Framework.

The proposed extension would extend further rearwards and be higher in height than the conservatory that it would replace. The proposed extension would result in a cumulative increase in floorspace to the existing dwelling by 29%. The evidence before me does not make a comparison based on the size of the ‘original dwelling’. Nevertheless, it appears that the proposed development would increase the floorspace of the original dwelling by at least 29%, which would considerably exceed the 10% limit set out within Policy 51 of the Local Plan. I appreciate that floor space is not the sole determining factor when assessing or measuring proportionality. The Framework refers to ‘size’ in relation to the original building, which can reasonably be interpreted to include volume, height, external dimensions, footprint or floorspace.

While dormers are a characteristic feature in the locality, the proposed development would significantly extend the main ridge of the dwelling and result in an increase in mass and bulk at first floor and roof level. The proposal would extend further rearwards than the existing conservatory and the existing first floor rear building line along this side of the road. The proposal would also extend the area of decking further rearwards into the garden and towards the countryside. Given the above and the fact that the proposal would considerably exceed the 10% limit set out within Policy 51 of the Local Plan, I find that the proposal would result in a disproportionate addition over and above the size of the original building.

For the reasons given above, I conclude that the proposed development would result in a disproportionate addition over and above the size of the original dwelling. As a result, the proposal would be inappropriate development in the Green Belt. The proposal would conflict with Policy 51 of the Local Plan and Policy G2 of the London Plan 2021. These policies among other things state that extensions or alterations to dwellinghouses in the Green Belt will only be permitted if the net increase in the floor area over that of the original dwellinghouse is no more than 10% and that development proposals that would harm the Green Belt are refused except where very special circumstances exist.

The proposal would also conflict with paragraph 149 c) of the Framework, which requires that extensions to dwellings within the Green Belt do not result in disproportionate additions over and above the size of the original building.

Openness is an essential characteristic of the Green Belt that has visual as well as spatial aspects. Even though the proposal would be largely screened from the public realm by existing vegetation and built form, glimpsed views would still be available of the proposed development from the public realm, including from the highway adjacent to the village hall. For the reasons set out above, the proposed extension would result in a disproportionate addition over and above the size of the original dwelling. The increase in volume and massing at first floor and roof level would result in a harmful loss of spatial openness and small loss of visual openness to the Green Belt; albeit this harm would be limited given the scale of the proposal.

For the reasons given above, I conclude that the proposal would harm the openness of the Green Belt and conflict with Policy 51 of the Local Plan and Policy G2 of the London Plan 2021. These policies among other things require that development does not harm the open character of the locality and that development proposals that would harm the Green Belt are refused except where very special circumstances exist. The proposal would also conflict with the Framework, which seeks to keep land permanently open.

The scale, form and materials would complement those of the host dwelling and the proposed dormers would provide a more balanced and symmetrical appearance. The proposal would provide an improve standard of accommodation for the occupants, including a dedicated home office space. I afford these other considerations limited positive weight.

While the appellant indicates that the replacement dwelling at [address] (No 15) is significantly larger than the original dwelling, there is limited information before me in relation to the size increase. In contrast to the appeal proposal, the first floor of No 15 is broadly in line with the first floor rear building line on this side of the road.

The proposed development would be inappropriate development in the Green Belt, which is by definition harmful to the Green Belt. Furthermore, there would be harm caused by the small loss of openness to the Green Belt from the proposed development. Paragraph 148 of the Framework is clear that substantial weight should be given to any harm to the Green Belt. Overall, I afford the other considerations advanced in this case limited weight in favour of the development. Accordingly, very special circumstances do not exist that clearly outweigh the harm to the Green Belt, by reason of inappropriateness and harm to openness.

For the reasons given above, the proposal would conflict with the development plan as a whole and there are no other material considerations, including the Framework, that would outweigh that conflict. Therefore, I conclude that the appeal should be dismissed.