Appeal 3372023

The appeal is allowed and planning permission is granted for the erection of part two storey & part single storey rear extensions to dwellinghouse at [site address] in accordance with the terms of the application, Ref 25/P/00499, subject to the conditions in the attached schedule.

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; 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 (the existing dwelling), which the appellant proposes to extend. The site 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 a listed exception 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. It does, however, define an original building as one as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally.

Policy P2 of the Guildford Local Plan: Strategy and Sites (2019) (the Local Plan) relies directly upon the Framework for its approach to development in the Green Belt and, as such, adheres closely to it.

The existing dwelling replaced one about which I have little information, save that it had an internal floor area of some 186m2 and is viewed by both parties as the original dwelling for the purposes of Green Belt policy. Permission was obtained for the erection of the existing dwelling in 19961. The application form described the (then) proposed development as including the demolition of a house, shed, and glass house with a gross floor area of 807m2.

[name] accept that some outbuildings may be considered as extensions to a main dwelling on the basis that they are normal domestic adjuncts, I have been provided with little reason to find that the shed and glasshouse in question were domestic; Indeed, given they appear to have had a floor area of some 621m2, the limited evidence before me suggests that they were likely not. Overall, I find the floor area of the original dwelling to be the only evidence upon which I can reasonably rely.

Whereas the original dwelling had a floor area of some 186m2, the appeal scheme would result in one with a floor area of some 508m2. Given these figures, 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, and conflict with Policy P2 of the Local Plan and with the Framework.

Openness is an essential characteristic of the Green Belt that has spatial as well as visual aspects. The appeal scheme would include additional built form where it did not previously exist and, as such, would have a spatial effect on openness. It would extend the dwelling at both ground and first floor levels, introducing development to spaces which are currently open. The site is quite secluded and direct visibility of the appeal scheme developments from outside the site would be limited and largely occur over medium and long distances from the south. From here, the extent to which the dwelling would appear altered by the appeal scheme would be limited, as the proposed extensions would be largely within the outline of the existing house. The additions would be visible from within the site. Overall, the appeal scheme would have a visual effect on openness.

Certificates of lawfulness2 have been issued for a series of single-storey rear extensions to the existing dwelling and for two domestic outbuildings. Not least as a result of the certificates, the possibility of these lawful schemes taking place is greater than theoretical. That said, I must consider what weight to attribute to the fallback position they comprise. 1 Application Ref 96/P/0063 2 Application Ref 23/P/01577, 23/P/01280 and 23/P/00897

Lawful scheme 23/P/00897 involves seven separate ground floor extensions, each 4m deep, added to the rear of the house. Small gaps would separate them. The Council views this scheme as one that would hinder the maintenance of external walls and create areas of potentially unusable space. To my mind, however, the gaps appear comparable to those often formed when rear extensions are added to terraced or semi-detached houses, which is to say, ones which do not generally prohibit development. I have been provided with little explanation as to how the internal layout would render the spaces unusable.

Overall, though it would create a somewhat unusual arrangement, and even if the appeal scheme is likely the appellant’s strong preference, both the lawful and appeal schemes ultimately comprise domestic projects which would enlarge the living space in the dwelling. As such, both may serve as an adequate solution to the same need or desire. Given this, I see no reason to view the lawful schemes as significantly less likely to be built than the appeal scheme.

The appeal scheme would result in some 508m2 of floor area, 2296m3 of built volume, and a footprint of 406m2. The lawful schemes would result in a footprint of some 589m2, a volume of 2629m3, and a footprint of 589m2. In these respects, the avoidance of the lawful schemes in favour of the appeal scheme would be a benefit.

The appeal scheme would introduce two-storey and roof-level additions and alterations to the dwelling, making the dwelling bulkier in a way which the lawful schemes would not. Even so, the lawful schemes would spread development across the site to a significant degree, creating three buildings, whilst the appeal scheme would result in more conventional additions to the existing dwelling, largely within its existing height and width. As such, the appeal scheme would better contain development spatially and visually, particularly when viewed from the south. Overall, the avoidance of the lawful schemes would, in these respects, comprise a slight benefit.

The Council’s concern that the certified outbuildings could be built following the erection of the appeal scheme, thereby undermining the benefits identified above, can be addressed by way of a condition removing Permitted Development rights. This would prevent not only the certified lawful schemes from proceeding but also prevent any comparable development.

The appeal scheme is inappropriate development in the Green Belt and erodes its openness. It is contrary to the aims of the Framework and to Policy P2 of the Local Plan. The harmful effects of the lawful schemes, however, would be greater. I have found little reason to view the lawful schemes as significantly less likely to be implemented. Allowing the appeal scheme would prevent the lawful schemes from proceeding and also restrict future development at the site. Overall, I find that 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.

Conditions 1 and 2 provide clarity. Condition 3 is required to ensure that the development does not harm the character and appearance of the dwelling or the area.

In respect of Condition 4, paragraph 55 of the Framework states that planning conditions should not be used to restrict national Permitted Development rights unless there is clear justification to do so. In this instance the appeal scheme is only acceptable because it results in a less harmful development than may be achieved using permitted development rights. In the absence of a condition restricting such rights, it would be possible for the dwelling to be extended by way of the appeal scheme, and then again subsequently using permitted development rights. That would undermine the rationale of this decision. As such, I find clear justification for the condition.

For the reasons given above, the appeal is allowed.

The development hereby permitted shall be begun before the expiration of three years from the date of this permission.

The development hereby permitted shall be carried out in accordance with drawings 2222_02, 2222_015, 2222_003, 2222_016, 2222_017, 2222_018, 2222_010, 2222_011, 2222_001, 2222_012, 3D Models of proposed visuals and Areas & [name] received on 31 March 2025, 2222_005 [name], 2222_025 [name], 2222_026 [name], 2222_027 [name], 2222_028 [name], 2222_020 [name], 2222_021 [name] and 2222_022 [name] received on 22 April 2025.

The external materials of the extensions hereby permitted shall match those used in the existing building/dwelling.

Notwithstanding the provisions of the Town and Country Planning (General Permitted Development) (England) Order 2015 (or any order revoking and re-enacting that Order with or without modification), no development permitted by virtue of [name], B, D, E, and F of Part 1 of Schedule 2 to the Order shall be undertaken. Schedule Ends