Appeal 3277324

The appeal is dismissed.

The title block of plan number 438G Prop-103 refers to ‘proposed elevations’ but it is annotated ‘existing rear elevation (south west)’. I have determined the appeal on the basis that this plan represents the proposed elevation.

The appeal site is in the Green Belt. Taking account of this, the main issues are: • whether the proposal would be inappropriate development in the Green Belt having regard to relevant development plan policy and the National Planning Policy Framework (Framework); • its effect on the openness of the Green Belt; and • whether the harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations, so as to amount to very special circumstances necessary to justify it.

The appeal building is a large, detached garage within the extensive grounds of a substantial house. The proposal is for a roof extension to provide a first floor store room, accessed by an external staircase.

Policy EE14 of the Runnymede 2030 Local Plan, July 2020 (LP) sets out the Council’s approach to extension and alteration of buildings in the Green Belt. It includes that the extension of a building is not inappropriate development provided that it does not result in disproportionate additions over and above the size of the original building. This is consistent with national policy on extensions to buildings in the Green Belt and the exception listed in Framework paragraph 149 c). Neither LP Policy EE14 nor the Framework define disproportionate additions but this policy refers to assessment against matters such as changes in footprint, floorspace, height, bulk, scale and mass (including roof form changes).

The footprint of the garage would not change. However, the floorspace would increase by 45.4m2 and result in a considerable uplift of 79.9% in area compared to existing. The ridge of the garage would increase by 2.6m and result in a significant uplift of 74.3% in height. The flat roof would be altered to a mansard form and although there is no objective volumetric measurement in evidence, it would clearly result in an appreciable cubic volume increase. Despite the limited projection of the dormer windows, the development would add substantial bulk above the building and, albeit to a much lesser extent, also to one side by virtue of the external metal staircase.

Considering the above, I find that the proposal would manifestly increase the overall scale and massing of the garage and fundamentally alter the extent of the building (approaching double the floorspace and more than half as much in overall height). Consequently, the extension would be a disproportionate addition over and above the size of the original building and, as such, it would be inappropriate development in the Green Belt. It would, therefore, conflict with LP Policy EE14 and fail to meet the exception set out in Framework paragraph 149 c).

Where an extension is found to be disproportionate and inappropriate development, it is also necessary to consider its effect on openness. The proposal would result in no increase in the spread or coverage of the garage on the site at ground level in proximity to site boundaries, the house or other outbuildings. However, the extension would result in development of appreciable floorspace, height, roof form, bulk and scale and massing on the site where none presently exists. In addition, while the staircase would be narrow with open spindles and handrail, this external structure nonetheless adds to development on the site.

Accordingly, even though there would be no public views of the site or any adverse impact on the visual openness of the Green Belt, this combination of factors means that the proposal would have greater impact on the spatial openness of the Green Belt than the existing development. This would be at odds with the aim of the Green Belt to keep land permanently open, and the purposes of including land within it, and would cause limited harm to the openness of the Green Belt. It would, therefore, not comply with LP Policy EE14 and conflict with Framework paragraphs 137 and 138.

The house is not a listed building and it is not in a Conservation Area. The design of the extension would integrate successfully with the garage, complement the house and remain subservient. It would also be high quality in sustainable external materials, function well, add to the overall quality of the area and be visually attractive as a result of good architecture. The main parties agree that the proposal would not have any adverse effect on the character and appearance of the area or on the living conditions of neighbours occupying nearby houses. I have no reason to reach a different view. In these respects, the absence of harm and compliance with the Council’s development plan and relevant objectives of the Framework are neutral factors in my

The house has been extended with planning permission granted by the Council and other outbuildings exist at the appeal site, as they do at other similar large houses nearby. The Council also granted planning permission for a garage taller than the existing garage (4.4m high), though I have not been informed what its overall size would have been. Nevertheless, it would have been significantly lower in height than the enlarged garage before me. I have, in any event, determined the appeal on its individual planning merits and against the relevant provisions of the Council’s development plan and the Framework.

The purpose of the extension, to provide additional domestic storage space, would enhance the appellant’s occupation and enjoyment of the house. [name] appreciate this aspiration, it would be a private benefit to those living in the property. It is not a factor in the proposal’s favour.

I have found that the proposal would be inappropriate development in the Green Belt, which would also be harmful to openness, contrary to local and national policy to protect it. The Framework requires me to give substantial weight to these harms and states that inappropriate development should not be approved except in very special circumstances.

The other considerations outlined above carry limited weight. They do not, therefore, clearly outweigh the substantial harm I have identified due to inappropriateness and loss of openness. Consequently, the very special circumstances to justify the proposal do not exist.

The proposed development would not accord with the development plan overall. There are no other material considerations, including the provisions of the Framework, which outweigh this finding.

For the reasons given above, I therefore conclude that the appeal should not succeed.