Appeal 3353087

The appeal is dismissed.

The description of development in the heading above has been taken from the planning application form. [name] of the appeal form it is stated that the description of development has not changed but, nevertheless, a different wording has been entered. Neither of the main parties has provided written confirmation that a revised description of development has been agreed. Accordingly, I have used the one given on the original application.

The National Planning Policy Framework (the Framework) was updated in December 2024. The parties provided comments on the relevance of the revised Framework to this appeal, and I have taken these into account in my decision.

The main issues are: • whether the proposal would be inappropriate development in the Green Belt having regard to the Framework and any relevant development plan policies; • the effect of the proposal on the openness of the Green Belt; and • whether any 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 the proposal.

Paragraph 154 states development in the Green Belt is inappropriate subject to several exceptions. These include 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.

Policy QP5 of the Royal Borough of Windsor & Maidenhead Borough Local Plan 2022 (BLP) protects the Green Belt from inappropriate development as defined in the Framework. Consequently, notwithstanding the recent changes to national Green Belt policies, BLP Policy QP5 is consistent with the Framework for the purposes of this appeal.

Neither the Framework nor BLP Policy QP5 specify how to assess whether a proposed extension, in combination with previous additions to the original building, would result in a disproportionate addition in terms of its size. This is a matter of planning judgement, having regard to factors such as floor area, volume, footprint and external dimensions.

The parties agree the floor area of the original building was 310m2 and previous additions have increased this by 42 per cent. They also agree the extension proposed in this appeal would result in a cumulative increase to the original floor area of some 59 percent. At well over half the original size, this would be a substantial cumulative increase in floor area.

The previous additions include a large, part two-storey rear extension, which added substantially to the volume and footprint, as well as the floor area, of the original building, and materially increased its plot coverage. Although there would be no further expansion of building footprint, the proposed extension would add appreciably to the volume of the house at the front. In addition, the right-hand wing of the building would become a continuous two-storey block of very considerable length, stretching from well in-front of the house’s principal frontage to well beyond its original rear elevation. Taking these factors together, I find the proposed development would result in a disproportionate addition over and above the size of the original building.

The exception for grey belt land at Framework paragraph 155 has been brought to my attention. However, there is no pertinent evidence the appeal site is in a sustainable location or that there is a demonstrable unmet need for the type of development proposed. Consequently, even if I were to find the surrounding area is built-up, the tests in paragraph 155 are not all met, so this exception does not apply.

For the above reasons, I conclude the proposal would be inappropriate development in the Green Belt, contrary to the Framework and BLP Policy QP5.

The fundamental aim of Green Belt policy, as set out in Framework paragraph 142, is to prevent urban sprawl by keeping land permanently open. Openness is also one of the Green Belt’s essential characteristics.

Openness can be perceived spatially and visually. Spatially, the proposed extension would materially increase the volume of [site address] . Given its height and bulk at first floor level, the development would also be clearly seen from the open land next door, the neighbouring dwelling and vehicles travelling towards Maidenhead. This is notwithstanding the dwelling’s set-back and mature perimeter planting. The effect on the visual openness of the Green Belt surrounding the site would be detrimental. Overall, there would be moderate harm to openness.

I have had regard to the desire of the appellant to provide accommodation for a live-in carer for the elderly occupiers of [site address] . However, I am mindful the harm identified would be permanent. There is also little to demonstrate other, less harmful ways to meet this need at the dwelling have been fully explored. I therefore give these personal circumstances limited weight.

In the other appeal decision brought to my attention1, the proposed extension had about half the floor area of the one before me. In addition, the Inspector found the original dwelling had a very modest initial size compared to others in the area, which does not apply in this case. Consequently, although he considered the proposed cumulative increase in floorspace over the original dwelling would be extensive, the Inspector nevertheless accepted the scale of the resulting dwelling. He also found no harm to openness, in part due to the size and spaciousness of the plot. I therefore find the circumstances in that appeal are not sufficiently closely related to those before me to be directly comparable, and I ascribe it little weight.

The Council has raised no concern with the design of proposed extension or its effect on the living conditions of neighbouring occupiers. On the evidence before me, I see no reason to disagree. However, an absence of harm in these regards is a neutral factor. An absence of objections also adds no positive weight in favour of the proposal.

Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. These will not exist unless the harm to the Green Belt is clearly outweighed by other considerations.

I am required to give substantial weight to the harm the development would cause to the Green Belt, including harm to its openness. Individually or cumulatively, the weights I have attached to the other considerations do not clearly outweigh this harm. Consequently, the very special circumstances necessary to justify the development do not exist.

I have found the proposal conflicts with the development plan, read as a whole. No other material considerations, including the Framework, have been shown to indicate that a decision should be taken otherwise than in accordance with it. Therefore, the appeal should be dismissed. [planning inspector] INSPECTOR 1 [name]/T0355/D/14/2223689