Appeal 3319905

The appeal is dismissed.

The Council’s report upon the planning application notes that the proposed development had commenced. At the time of my visit, the proposed extension was substantially complete, but did not include any external render. I have considered the appeal on the basis of the planning application as submitted.

The main issues are: • whether the development would be inappropriate development in the Green Belt having regard to the National Planning Policy Framework (the Framework) and any relevant development plan policies; • the effect of the development 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 the very special circumstances required to justify the proposal.

The appeal site is a large plot in a semi-rural location within the Green Belt, at the end of a short-terraced row, with an extensive garden to the side and rear.

Policy CS5 of the Warrington Borough Council Local Plan [name] 2014 (CS) recognises the purposes of the Green Belt and sets out that development proposals within the Green Belt will be approved where they accord with relevant national policy. The Framework identifies that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open. It goes on to state that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. The Framework also sets out that the construction of new buildings in the Green Belt should be regarded as inappropriate. Limited exceptions to this include that at paragraph 149 c), which refers to the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building1.

While the Framework does not define what might be considered a disproportionate addition, the [address] Extensions Supplementary Planning Document 2021 (SPD) addresses the exception, albeit with reference to an earlier version of the Framework. The SPD sets out that any extensions and additions that result in an increase in size of over 33% to the original building will be considered to be disproportionate and therefore unacceptable. The assessment is made in terms of both internally measured floorspace, and externally measured volume.

The appellant suggests that as the existing detached outbuildings form some 9% of the appeal site area, they should be discounted. However, the SPD makes clear that covered and enclosed curtilage structures such as pergolas, car ports and similar structures will all count towards this assessment; and that any previous extensions and detached buildings that have been added to the original property will be counted towards the resulting size.

The assessment submitted with the planning application detailed an increase of less than the SPD threshold, but from the evidence before me, no account had been taken of previous additions which comprised a porch and other outbuildings (the previous additions). When set against the original dwelling, the Council calculated that these amounted to an increase of 68.98% in floorspace and a 42% increase in volume; and that the proposal would result in an increase of some 100% in floorspace, and some 70% in volume.

The appellant has submitted an assessment to the appeal, which differs in some respects to that of the Council, and it does not include any volume figures. The appellant calculates that the previous additions represent an increase in floorspace of some 59% when compared to the original dwelling; and that the proposal would result in an increase of some 85.9%. Thus, on either assessment by the main parties, the proposal would substantially exceed the SPD threshold.

I therefore conclude that the proposal would be a disproportionate addition to the original dwelling. It would therefore be inappropriate development in the Green Belt, in conflict with Policy CS5 of the CS, the SPD and the Framework.

Openness is an essential characteristic of the Green Belt. It has a spatial aspect as well as a visual one. ‘Open’ can mean the absence of development in spatial terms, and it follows that openness can be harmed even when development is not readily visible from the public realm.

The main parties also differ in their assessments of the size of the proposed extension and the now demolished structures it would effectively replace. The 1 ‘Original building’ is defined as a building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally. appellant details a smaller size than the Council in this regard, with a net increase in floorspace of some 16.5m2. Using the Council’s figures, the net increase would be some 17.7 m2. The Council also details the volume for these elements, and on this basis, the net increase in volume would be some 54.03m3. Regardless of the differences between the main parties, there would be a considerable impact upon the spatial aspect of openness.

The openness of the Green Belt is evident around the appeal site, with open fields adjacent to its western and southern boundaries. Outbuildings are located along its southern boundary, with further sheds located adjacent to the western boundary. To the east on the opposite side of [address] are further open fields, and the large site of [name] towards the north.

The proposed extension would be shallower but wider than the now demolished conservatory and lean to structure. It would occupy almost the full width of the rear elevation, save for a very small setback on each side. There are no public views towards the rear of the property. Due to the presence of hedging and other vegetation along [address] and the southern boundary of the appeal site, together with the existing outbuildings on the southern boundary, the extension is largely screened from view along [address] approaching from the south.

I therefore conclude that the openness of the Green Belt would be significantly reduced in spatial terms, but to a limited extent in visual terms. The proposal would fail to preserve the openness of the Green Belt, and it conflicts with Policy CS5 of the CS, the SPD and the fundamental aims of the Framework.

The appellant draws my attention to a potential fallback position, by virtue of the permitted development rights as detailed in the GPDO2. While the appellant has submitted example calculations in this regard, this is not supported by any certificates of lawfulness, nor detailed on any plans. Furthermore, there is no compelling evidence before me to demonstrate the lawfulness of all of the previous additions. I therefore cannot be certain that such rights could be implemented, nor that any potential fallback position is more than a theoretical prospect, nor that any such fallback position would be more or less harmful than the appeal scheme. I therefore attach little weight to this matter.

The main parties agree that the design of the proposal would have no adverse impacts upon the character and appearance of the host property, nor the wider area, nor upon the amenity of adjacent neighbouring occupants. The extension would appear subservient to its host, and thus accord with the design criteria within the SPD. I find no reason to consider otherwise in these matters. However, the absence of harm in such matters is a neutral factor in my assessment, carrying neither positive nor negative weight, as does the absence of any objection to the proposal.

There is little evidence to demonstrate that the proposed extension would deliver a low-carbon and/or more energy efficient development, but I accept that in principle this could assist in meeting the demands of climate change. Such benefits would be small in scale and of limited weight. The extension would also fulfil a desire to extend a home, but such matters are of a personal 2 The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) benefit and attract very little weight. Nevertheless, the extension of an existing home might reduce housing need and contribute to the efficient use of land, which attracts limited weight due to the scale of the proposal.

The proposal would be inappropriate development in the Green Belt that would reduce openness. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. In addition, openness is an essential characteristic of the Green Belt, so a reduction in openness would also be harmful, in this case to a significant degree in spatial terms and to a limited extent in visual terms. I am also required to give substantial weight to any harm to the Green Belt.

In this case, it is clear that the limited benefits arising from the proposal would not outweigh the substantial harm I have identified. Consequently, the very special circumstances necessary to justify the proposal do not exist.

For the reasons above, I conclude that the appeal should be dismissed. [planning inspector] BA (Hons) [name]