Appeal 3325825

The appeal is dismissed.

An application for costs was made by [name] against the Council of the Royal Borough of Windsor and Maidenhead. This application is the subject of a separate Decision.

The Government published in December 2023 a revised version of the National Planning Policy Framework (the Framework). Given the similarities with the previous Framework with regards to Green Belt issues, I am satisfied that no party would be prejudiced by making reference to the Framework in this

The appellant references a certificate of lawfulness1 for single storey side extensions, which was permitted after the decision date of the proposal before me. Given that the Council have referred to and considered ‘single storey side extensions that could be built under permitted development ‘ in their officer report, I do not consider that the interest of natural justice are compromised by my consideration of this certificate of lawfulness.

The appeal site is located within an area of Green Belt. Accordingly, the main issues are: • whether the proposed development would be inappropriate development in the Green Belt having regard to the Framework and relevant development plan policies; 1 Application reference 23/01569/CPD • the effect of the proposal on the character and appearance of the host dwelling; and • if the development would be inappropriate, whether the harm to the Green Belt by way of inappropriateness and any other harm, would be clearly outweighed by other considerations so as to amount to the very special circumstances necessary to justify it.

The Framework states that the construction of new buildings is to be regarded as inappropriate development subject to the exceptions which are set out in paragraph 154. Part c) of this paragraph lists 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, as one such exception.

Policy QP5 of the Borough Local Plan 2013-2033 (2022) (LP) protects the Green Belt from inappropriate development and states that planning permission will not be granted, unless very special circumstances are demonstrated.

The existing detached dwelling has been extensively extended, with a large rear/side two storey projection and rear conservatory. The appellants do not dispute the Council’s assertion that these existing additions add up to a 68% increase in the floorspace of the original property.

The proposal would add a single storey side addition and front porch, and extend the existing single storey rear extension, increasing the footprint of the property, in addition to extending the dwelling at first floor level to the rear, resulting in side elevations of substantial depth and massing. The proposal would add a further 57sqm, resulting in a total additions adding up to some 116% of the original property. I consider that the doubling of the floorspace of the original property would be significant and would amount to a substantial increase in the form, bulk and overall scale and size of the original building.

Neither ‘disproportionate’ nor ‘limited extension’ is defined in the Framework or Local Plan. However, it is clear that the scale of the existing additions has led to a substantial increase in the size of the original building and a further increase in size as proposed would result in an original building that would be engulfed by extensions.

In light of the above I conclude that the further additions proposed would comprise a disproportionate addition over and above the size of the original building and would result in inappropriate development in the Green Belt, as set out in LP Policy QP5 and paragraph 154 of the Framework.

The Framework makes it clear that openness is an essential characteristic of the Green Belt.

The proposal would increase the footprint of the dwelling and would, given the addition of the rear first floor projection above the previous conservatory, increase the massing and built form of the property at first floor level, particularly at its sides and rear. Whilst the property is set back and mostly obscured from the highway by roadside vegetation, the development would be visible from the surrounding open land. There would be therefore a visual impact upon openness in addition to the spatial impact that would result, and openness would be reduced. Substantial harm to openness would therefore occur.

As set out above, the existing property has clearly been extensively extended. The modest frontage of the dwelling is extended to the rear at two storey level substantially, and the additional two storey side/rear element, visible from the front, results in a significant massing, depth and width.

Whilst mirroring the existing roof of the original property, the first floor rear extension would have the appearance of adding the dwelling frontage to its rear, connected by the substantial rear projection. The resultant roof form, when viewed from either side elevation, would be overly complicated and incongruous. The ensuing built form would dominate and substantially compromise the original character of the roof and property. The scale and massing of the additions, including the proposed flat roofed single storey side addition, would result in the property being engulfed by extensions.

The existing rear conservatory is modest single storey structure and as such its removal does not mitigate for the visual impact of the proposed additions. Similarly, the use of matching materials and matching the eaves height would not compensate for the visual impact of the extensions as set out above.

As such, the proposal would harm the character and appearance of the host dwelling. There would therefore be conflict with LP Policy QP3 and Policy GEN 2 of the Hurley and the Walthams Neighbourhood Plan (2017), which require high quality design which reflects the character of the existing property. These policies are in broad conformity with the Framework. There is also conflict the guidance set out in principle 10.1 of the Supplementary Planning Document Borough Wide [name] (2020) which requires extensions to respect the main building they relate to and be subordinate.

The appellant makes reference to potential ‘multitude of side extensions’ that could be erected under permitted development rights, and their comparative impact upon character and appearance. Extensions granted under permitted development rights are not considered against or subject to the relevant development plan polices and supplementary planning document guidance. As such, in this regard, I cannot give these permitted development extensions weight in favour of the proposal.

In terms of green belt considerations, the certificate of lawfulness referenced above allows for the addition of ground floor accommodation. This would not provide the substantial additional bedroom accommodation that the proposed first floor extension would provide, and as such, is not directly comparable.

Moreover, in terms of the visual impact on openness, the extensions allowed under the above referenced certificate of lawfulness may, compared to the proposal before me, increase the footprint and floor area/volume of the dwelling, particularly when viewed from the frontage and in glimpses from the highway. However, the ground floor extensions would not be comparable with the visual prominence of the additional massing, scale and bulk of the proposed extension at first floor level.

Consequently, even if I found that there was a real prospect of the fall-back being implemented, it would not be demonstrably more harmful to the openness of the Green Belt than the proposal. For these reasons, I have given the fall-back position only limited weight in favour of the proposal.

Similarly, a potential replacement dwelling on this site would have to be considered against relevant Framework and development plan policies. In the absence of any details of such a development, even if I were to consider this a realistic fallback position, it is not possible for me to compare such a scheme with the proposal before me. I cannot therefore give a possible replacement dwelling weight in favour of the proposal.

Even if a condition to restrict permitted development rights passed the tests set out in the Planning Practice Guidance, this would not overcome the harm I have identified with regard to the impact upon openness and character and appearance of the proposed extensions, particularly the first floor element. This limits the weight I can give to such a condition.

The suggestion that the proposal would have a lesser impact upon flood risk and flood storage capacity than the fall-back position outlined above is not substantiated. As such, this again limits any weight I can give to this mater.

Paragraph 152 of the Framework says inappropriate development is harmful by definition and paragraph 153 identifies that substantial weight should be given to any harm to the Green Belt.

The proposal would amount to inappropriate development in the Green Belt, and further harm to the Green Belt would be caused as a result of the loss of openness. Additional harm would be caused to the character and appearance of the existing dwelling. These matters carry substantial weight. Moderate weight at best can be given to the considerations cited in support of the proposal. Consequently, the considerations advanced by the appellant do not clearly outweigh the harm to the Green Belt that I have identified. Accordingly, very special circumstances necessary to justify inappropriate development in the Green Belt do not exist. The proposal therefore conflicts with the Framework.

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