Appeal 3361941

The appeal is dismissed.

The main issues are: • whether the proposal 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 on the openness of the Green Belt. • the effect of the proposal on the character and appearance of the area; and • on the basis that the proposal would be inappropriate development in the Green Belt, whether any harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations so as to amount to very special circumstances required to justify the development.

The Framework establishes that development within the Green Belt should be regarded as inappropriate unless one of the specified exceptions applies. Exception (c), as set out in paragraph 154 of the Framework, allows for the extension and alteration of a building, provided that it does not result in disproportionate additions over and above the size of the original building. Policy P2 of the Guildford Borough Local Plan (GBLP) refers to the exceptions within the Framework and confirms that the original building is that as it existed on 1 July 1948 or the first building as it was originally built.

Based on the Appellant’s figures, the proposal would result in a gross increase in internal floor area of 15 sqm (6.8%) compared to the existing. The appellant’s and the Council’s figures do not fully align, and there is a reference to a mixture of floor areas and footprint. Nonetheless, the Council suggest that the original property had a floor area of 105 sqm, and that cumulatively there would be a 223% increase in floor area. I have not been provided with a full breakdown for this percentage increase; however, it is clear from my observations and the planning history that the property has undergone substantial extensions previously, notably a flat roof two-storey side extension and single-storey elements to the rear. There is no indication as to whether the Council have considered the outbuilding as part of the original building, but even allowing for that, the property has been significantly increased.

Neither the Framework nor policy P2 define ‘disproportionate additions’. It is as set out in the Council’s Green Belt Supplementary Planning Document (SPD), a judgement based on various factors, not just percentage increases, but it is an assessment against the original, not the existing building. While the net increase in floor area is limited and the proposed development is all single storey, it would create an elongated rear projection. Cumulatively, with previous extensions, there would be a significant increase from the size of the original dwelling.

Consequently, the proposal would result in disproportionate additions and would be inappropriate development in the Green Belt, having regard to the Framework and GBLP Policy P2 and the Green Belt SPD.

The Framework states that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open. Openness in terms of the Green Belt has both spatial and visual aspects.

Effectively infilling between the house and outbuilding (albeit replaced) and in the context of the setting as part of a residential road of large, detached properties, the impact on the wider appearance of the Green Belt would be negligible. Nonetheless, there would be a spatial increase in built form, particularly with regard to the rear projection, and whilst localised, it adds to the harm to the Green Belt.

The design and materials of the proposed extension reflect the existing building. The section linking to the house is to be subservient, and the main element effectively replicates the form of the outbuilding it replaces, but with an increased length and a slight increase to the width and height. The latter aspects would not be material; however, creating a projection from the rear elevation of close to 20m would result in a substantial extension.

In relation to rear extensions, the Council’s Residential Extensions and [name] advises that the optimum length of an extension should reflect the scale, proportion and mass of the existing property. The lack of visibility does not alter this, and while giving due regard to the existing outbuilding being replaced, the proposal forms a continuous length of built form which would be of a significant scale, not dissimilar to the width of the existing property, and would be an unduly large and disproportionate rear protrusion.

I accept that Oakdene is relatively modest compared to other properties along the road, and it sits within a large plot. The proposal would not alter its visual relationship with the surrounding area and would not adversely impact the neighbours. It would, nonetheless, be out of scale with the host property, contrary to policies D1 of the GBLP: Strategy and Sites (2019), D4 and H4 of the GBLP: Development Management Policies (2023), the [name] and [name] (2018) and the [site address] Neighbourhood Development Plan (2020-2034). Together, these seek high-quality design which takes into account the form, scale, and proportions of the existing building.

The decision notice refers to policy H5, which I have not been provided a copy of. However, I assume this is a typo and should be H4 which relates to extensions and is referenced in the officer’s report.

The appellant has referred to some examples of development elsewhere in the Green Belt, and whilst these appear to result in large increases in floorspace, they are not directly comparable in terms of their design. Two relate to bungalows being converted to a two-storey house, and the other is an extension above a garage. While accepting that visually, these are more prominent additions than a single-storey addition to the rear of a property, the full background to each of these cases is not before me. Moreover, each proposal is to be considered on its own merits, with the assessment in relation to inappropriate development relating to the original building, not a comparison to other buildings.

It is indicated that the existing outbuilding is structurally unsound. Green belt policy does allow for replacement buildings, however, as this proposal is for an extension, it has been considered under exception (c), not (d) of the Framework.

Very special circumstances can only exist if the harm I have identified is clearly outweighed by other considerations. I have found harm to the Green Belt by way of inappropriateness and openness, and other harm in terms of the impact on the host property. As set out in paragraph 153 of the Framework, substantial weight is given to harm to the Green Belt. Despite having regard to all the other considerations put before me in favour of the scheme by the appellant, I conclude that these other considerations taken together do not clearly outweigh the harm that I have identified to the Green Belt.

The development would conflict with policy P2, which relates to development in the Green Belt and policies D1, D4 and H4 in relation to design and the scale of new development. Accordingly, the very special circumstances necessary to justify the proposal do not exist.

For the reasons set out above, I conclude that the appeal should be dismissed.