Appeal 3271743

The appeal is dismissed.

Following the submission of the appeal, the Government published the National Planning Policy Framework 2021 (the Framework). I sought comments from the main parties with regards to this matter and, where these have been received, I have taken them into account in my assessment.

The main issues are: • Whether the proposal would be inappropriate development in the Green Belt, having regard to the Framework and relevant policies of the Development Plan; • The effect of the proposal on the openness of the Green Belt; • The effect of the proposal on the character and appearance of the host dwelling and the area; and, • If the proposal is 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 it.

Policy CS13 of the Hertsmere Local Plan Development Plan [name] (January 2013) (CS) states that there is a general presumption against inappropriate development within the Green Belt, as defined on the [name] and such development will not be permitted unless very special circumstances exist. Development proposals, including those involving previously developed land and buildings, in the Green Belt will be assessed in relation to the NPPF.

Policy SADM26 of the Hertsmere Local Plan Site Allocations and Development Management Policies Plan (ADMPP) establishes the principles for development in the Green Belt. It states that the scale of development will be controlled and requires that an extension or alteration to a building must not individually or cumulatively be disproportionate to the original building; the addition(s) must be subordinate to the original. The original building is defined as the building that was in existence on 1 July 1948, or if built after 1 July 1948, as so built.

Paragraph 149 of the Framework makes it clear that new buildings in the Green Belt should be regarded as inappropriate, with a limited number of exceptions. This includes at paragraph 149 c), 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.

The Framework does not define what would constitute a disproportionate addition over and above the size of the original building. ADMPP Policy SADMA 26 states that the addition(s) must be subordinate to the original. As such, I have had regard to the increase in floor space that would be created under the proposal, as well as considering the proposal more generally with regards to its scale. This is the general approach that the Council indicates it will follow under ADMPP Policy SADM26.

The Council indicate that the original dwelling had a footprint of [address] metres with the first floor having an area of 63.[address] metres. Planning permission was granted for a two storey side and rear extension under application TP/08/0696, which has been implemented. This increased the footprint of the building to [address] metres and the first floor area to 112.[address] metres.

The Council calculate that the proposal would add a further 60.[address] metres to the ground floor. This would, according to their figures, increase the footprint of the building to 196.[address] metres, which would be 121.[address] metres over and above the original footprint of the building. This would represent a percentage increase of 162.6%.

The appellant states that the Council has not provided any evidence to demonstrate how they have reached the figure of [address] metres in terms of the footprint of the original building. They calculate that the existing extensions and the appeal proposal would result in a cumulative increase to the floor areas of the dwelling by 45.7%, although their [name] suggests that it would be an overall increase of 48%.

The appellants’ calculations are set out in the table at figure 4 of their statement. These appear to dispute the figures that the Council have provided. However, the table does not refer to the original building as the starting point, rather the first column of the table is titled ‘Pre 2008 Existing’. It is not clear from the information before me how the appellant has calculated the pre 2008 existing floor areas and whether this represents the original building. Consequently, and in the absence of compelling evidence to suggest that they are incorrect, I consider that the Council’s figures represent a more accurate percentage increase than the appellants’.

From the above, it is clear that the previously approved two storey side and rear extensions have significantly enlarged the original building in terms of its scale, bulk and massing. The proposal would further significantly increase the size of the original building and result in additional bulk and massing to it.

Consequently, when considered in conjunction with the previous extensions to the building, the proposal would result in a dwelling considerably larger than the original. As such it would be disproportionate in size to the original building and would therefore represent inappropriate development in the Green Belt.

For the reasons set out above, the proposal would represent a disproportionate addition to the original building which would conflict with CS Policy CS13 and ADMPP Policy SADM26. There would also be conflict with the Framework. [name] do not consider that any of the other exceptions of the Framework apply to the proposal, it represents inappropriate development that is, by definition, harmful to the Green Belt1.

Paragraph 137 of the Framework states that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence.

The proposal would extend the appeal dwelling, resulting in a visually larger mass of development. This would result in a spatial and visual change to the property and its environs and the openness of the Green Belt would be reduced. Although the reduction in openness would be limited and localised, it would nonetheless cause harm to the Green Belt.

I am mindful of the appellant’s comments that the appeal site is well screened from [address]. I also observed that the proposal would not be visible from neighbouring properties due to existing boundary treatments. For the same reason, only glimpsed views of the proposal would be likely to be possible from the adjacent agricultural land.

However, openness is an inherent characteristic of the Green Belt and development does not have to be publicly visible for harm to openness to occur. Moreover, the fact that the proposed extension would use matching materials to the existing dwelling does not negate this harm. In addition, while the proposal would retain large areas of the land surrounding the dwelling, it would nevertheless reduce the visual and spatial openness of the Green Belt.

In accordance with Paragraph 148 of the Framework, I afford the harm to the openness of the Green Belt substantial weight.

The appeal site is located in the countryside between the built up areas of Radlett and Borehamwood. It is set in large gardens with a small number of large, detached dwellings to the north. These have different forms and design and sit in substantial grounds. To the south and the east (rear) the appeal site is bounded by agricultural land. 1 Paragraph 147 of the Framework.

The proposed extension would include a large expanse of flat roof, which in conjunction with its depth and width would result in it appearing as an elongated box-like structure. Although there is an existing single storey structure to the rear of the appeal dwelling with a flat roof, this appears proportionate to the building and complements its character and appearance. By contrast, the proposal would fail to relate well to, or respect the architectural integrity of the host dwelling, and would appear out of proportion to it. In my view, the proposal would be a poorly designed and out of scale addition that would cause harm to the character and appearance of the host dwelling.

In reaching this conclusion, I note the appellants’ comments that they consider a pitched roof in this location would lead to a feeling of overbearingness and would not therefore be appropriate. I have also been referred to the guidance set out in the Hertsmere Local Development Framework Supplementary Planning Document Planning and [name]: Guidelines for [name] and [name] 2006. However, a flat roof solution of the size and extent proposed would be unacceptable for the reasons I have set out above.

The proposal would not be readily visible from [address], neighbouring properties or the adjacent agricultural fields. It would not, therefore have a harmful effect on the character and appearance of the wider area. However, this does not overcome the harm that I have identified would occur with respect to the host dwelling.

I conclude that the proposal would cause harm to the character and appearance of the host dwelling. There would be conflict with CS Policy CS22 and ADMPP Policy SADM30. In summary, these require development to be of high quality design and to make a positive contribution to the built and natural environment. There would also be conflict with the overarching aims of the Framework.

I note the appellants’ comments that the proposal would provide a larger recreational space along with office space to facilitate the needs of the owner to work from home. I consider these matters to be principally private benefits and I afford them limited weight.

The proposal would not cause any harm to the living conditions of the occupants of neighbouring dwellings. It would also leave sufficient space around the dwelling for the enjoyment of the occupants. However, the absence of harm in respect of these matters is a neutral factor in my overall considerations.

The Framework clearly advises that substantial weight should be given to any harm to the Green Belt. In this case, there would be harm by reason of inappropriateness, as well as harms arising in relation to loss of openness and in respect to the character and appearance of the host dwelling.

I find that the other considerations in this case do not clearly outweigh the harm that I have identified. Consequently, the very special circumstances necessary to justify the development do not exist. The proposal would conflict with the Development Plan and the Framework and there are no material considerations in this case that indicate a decision other than in accordance with the Development Plan and the Framework.

For the above reasons, having considered the development plan as a whole, the approach in the Framework, and all other relevant material considerations, I conclude that the appeal should be dismissed.