Appeal 3355798

The appeal is dismissed.

Rather than use the description of development on the application form in the banner above, I have used the one from the decision notice and appeal form as it more accurately describes the proposal.

The main issues are: • whether the proposal would constitute inappropriate development in the Green Belt having regard to the National Planning Policy Framework (the Framework) and any relevant development plan policies; • the effect on the openness of the Green Belt; • the effect of the proposal on the character and appearance of the host building and surrounding area; 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.

The appeal site includes a detached dwelling with a generously sized garden beyond. It is in the Green Belt. The Framework states that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open, that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances, and that development in the Green Belt is inappropriate unless one of a list of provided exceptions applies.

One such exception, at paragraph 154(c), is 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 ‘disproportionate additions’, leaving whether any particular proposal would amount to one as a matter of planning judgement.

The development plan comprises the Hillingdon Local Plan (2012 & 2020) and the London Plan (2021). For the purposes of this appeal, the pertinent development plan policies differ from the Framework insofar as they support extensions only where there would be no greater impact on the openness of the Green Belt. This is with regard to specific characteristics listed thereafter. I have been presented with no argument that this approach is inconsistent with that of the Framework, and see no reason to view it as being so.

The appellant does not contest the Councils assessment that the proposed extensions would result in a 129% increase in floor area compared to the existing dwelling, and also increase the width of the two-storey element of the property by 6.3m. These are significant increases in both respects. Moreover, I have been provided with very little from the appellant to explain why they feel this would result in a proportionate addition. Given the above, I find that the proposed development would result in a disproportionate addition over and above the size of the original building. It would be inappropriate development in the Green Belt.

Openness is an essential characteristic of the Green Belt that has spatial as well as visual aspects. The proposed development would include additional built form where it did not previously exist and, as such, would have a spatial effect on openness. It would be visible from [address], from neighbouring plots, and from within the site itself. As such, it would have a visual effect on openness. Given the above, the proposal would result in a harmful loss of openness overall.

The host dwelling is at the far end of [address]. Up to the appeal site, the street possesses a degree of consistency, borne of a planned, suburban layout of semidetached dwellings. However, these are not uniform in either their basic form, or in the various ways they have been extended and altered over time. There is some variation in the street, therefore. Moreover, the appeal site is noticeably distinct from the rest of the street, it has a larger, irregular plot, and the dwelling it hosts bears little resemblance to its neighbours in either form or style.

In addition to being noticeably different to the neighbouring buildings, the appeal site dwelling is unremarkable in appearance. Overall, this gives scope to alter the appeal site dwelling significantly without harming either the site or the street.

The proposal would result in a building with little in common with its neighbours in a design sense, but that is the position already, so no harm would arise. The proposed extension would be subservient to the host dwelling insofar as it would be set down at the ridgeline, and back from the front elevation at first floor level. The roof form would be traditional, and matching to the host, and suitable external materials could be ensured via the imposition of planning conditions. A gap would be left to the western boundary, similar in width to that left by No [address] on the other side. This would maintain a reasonable distance between the dwellings.

Whilst the width of the two-storey side element would increase the bulk, mass, and presence of the dwelling, this would be mitigated by the subservient and complementary features described above.

The proposal would not harm the character and appearance of the host building and surrounding area, and would comply with the pertinent requirements of Policies BE1, DMHB 11, DMHB 12, and DMHD 1 of the Hillingdon Local Plan.

I have found the proposal to be acceptable in terms of its effect on the character and appearance of the site and area. In addition, the Council has raised no concerns as to the effect of the proposal on neighbouring occupiers, and I see no reason to view matters differently. These, however, are reasonable expectations of any development, rather than benefits.

A previous, comparable proposal to extend [site address] was refused and a subsequent appeal dismissed. I recognise that the scheme before me comprises a revised design. However, I have assessed the scheme on its own merits; how it compares to the previous proposal plays no part in my determination.

The proposal would constitute inappropriate development in the Green Belt and would harm openness. As such, the Framework requires that the harm by reason of inappropriateness be given substantial weight, and that inappropriate development should not be approved except in very special circumstances. Very special circumstances will not exist unless the harm to the Green Belt and any other harm is clearly outweighed by other considerations.

The other considerations in this case are not sufficient to comprise the very special circumstances necessary to justify this development. The development is contrary to Policies G2 of The London Plan and DMEI 4 of the Hillingdon Local Plan, and with the Framework, which seeks to protect the Green Belt.

I have considered all other matters raised but none outweigh the conclusions I have reached. The proposal conflicts with the development plan overall and the material considerations do not indicate that the appeal should be decided other than in accordance with it. The appeal is dismissed, therefore.