Appeal 3375456

The appeal is allowed and planning permission is granted for small rear extension to square off back of house, extend side extension to back of house at [site address] in accordance with the terms of the application, Ref 5/25/0687, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with drawing nos 84_P_110, 84_P_210, 84_P_211, 84_P_212, 84_P_213 and 84_P_214.

The external materials of the extension hereby permitted shall match those used in the existing dwelling.

The main issues are:  whether the proposal would be inappropriate development in the Green Belt;  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.

The appeal site lies within the Metropolitan Green Belt. The National Planning Policy Framework (the Framework) states that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances.

In this regard, saved Policies 1 and 13 of the [site address] District Local Plan Review 1994 (LP) sets out exceptions for new development in the Green Belt. This includes extensions to houses, unless the scale or visual impact upon the original building would create a building of significantly larger or different character.

The LP policy is broadly consistent with the Framework exceptions to inappropriate development in the Green Belt, including paragraph 154c), which allows for 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. For the purposes of Green Belt policy, the original building is the building as it existed on 1 July 1948 or, if constructed after this date, as it was originally built.

Neither the Framework nor the LP policies define what a disproportionate addition would be. However, whilst it is of some age, the Supplementary Planning Guidance: [name] and [name] in the Green Belt 2004 (SPG) provides guidance on what constitutes disproportionate additions, to help assess proposals in the Green Belt.

The SPG suggests that side and rear extensions should generally not exceed 180m3 or a 40% increase in floorspace (so long as it does not result in a cubic content above 300m3). The SPG stresses, however, that these figures are not rigid limits and are also subject to how well a proposal performs against a range of other criteria. This includes, but not limited to the type of extension, previous extensions and visibility from public viewpoints.

The property has recently been extended with a part single/part two storey side and rear extension, partly utilising permitted development rights. This has resulted in an approximate 47% increase in floorspace and 183m3 volume over the original dwelling, marginally exceeding the SPG thresholds.

The appeal proposal involves two, single-storey infill extensions to square-off the rear of the appeal property. Cumulatively, in combination with the existing extensions, the proposal would result in a 58% increase in floorspace and a volume of 218m3 compared to the original dwelling, further exceeding the SPG guidelines.

Whilst a quantitative assessment is useful in determining whether an extension would be disproportionate addition, it is not the only consideration. Qualitative factors are also important. The development performs well against qualitative criteria iii,iv,v and vi of paragraph 7.1 of the SPG. Visually, the extensions would appear subordinate to the host dwelling, reflecting the roof form of the existing single-storey elements, with a very modest increase in depth. The original two-storey dwelling would remain the dominant feature. Furthermore, the proposal would have minimal visibility from public vantage points and would not close any gaps between dwellings. I also note that the Council in their assessment of the proposal, considered the increase to be of an appropriate scale in relation to the original dwelling, with no harmful cumulative effect, considerations which I agree with.

Considering all the above points, I am satisfied that in this particular case, the proposed development, viewed cumulatively with the previous extensions, would not result in a disproportionate addition over and above the size of the original building, despite exceeding the size guidance set out in the SPG. On this basis, I find that the proposal would not constitute inappropriate development in the Green Belt and would accord with the Framework and [name] 1 and 13.

[name] have found the development would not constitute inappropriate development within the Green Belt, there is no requirement for me to assess the effect of the proposal on the openness of the Green Belt or consider whether there are other considerations and whether they amount to very special circumstances to justify the proposal.

In addition to the standard conditions relating to timeliness and the identification of plans, the Council has suggested a condition requiring the external materials of the proposed development to match those of the existing building. In the interests of the character and appearance of the area, I consider that this is necessary.

For the reasons given above and having had regard to all other matters raised, I conclude that this appeal should be allowed.