Appeal 3365230

The appeal is allowed and planning permission is granted for a detached garden building to provide facilities for the dwellinghouse at [site address] in accordance with the terms of the application Ref 25/00120/FUL subject to the following condition: The garden building hereby permitted shall be used only for purposes incidental to the residential use of the property known as [site address] , [site address] , [postcode] .

The garden building referred to in the description of the development is already erected, and the appellant wishes to retain it. I shall therefore treat the appeal as if the original application had been made under section 73A of the Act1.

The garden building is to be used for purposes incidental to the use of the dwelling, including a gym, sauna, games room and a bedroom/bathroom to be occupied by a disabled relative, the appellant’s mother.

The application site lies clearly outside the settlement of [site address] in designated countryside and within the Bristol and Bath Green Belt (GB).

The main issue is whether the development would be inappropriate development in the GB.

The Framework2 establishes that the construction of new buildings in the GB should be regarded as inappropriate unless one of the specified exceptions applies. These include the extension or alteration of a building provided that it does not 1 The Town & Country Planning Act 1990 (as amended) 2 The National Planning Policy Framework result in disproportionate additions over and above the size of the original building. The Council has treated the garden building as an extension to the original building, which is a detached dwelling set in a generously sized curtilage. Having regard to that seen on site and the judgment in the Warwick3 case, I have no reason to disagree with the Council’s decision to treat the outbuilding as an extension.

The Council refers to three development plan policies governing development in the GB.

Policy CP8 of the Bath and [name] (CS) provides that the GB will be protected from inappropriate development in accordance with national planning policy.

Policy GB1 of the Bath and North East Somerset Placemaking Plan (PP) requires that development should seek to enhance the visual amenities of the GB.

Policy GB3 of the Bath and North East Somerset Local Plan [name] (LP) deals specifically with extensions and alterations to buildings in the GB. It provides that proposals to extend or alter a building in the Green Belt will only be permitted provided they would not represent a disproportionate addition over and above the size of the original building.

Thus, CS policy CP8 and LP policy GB3 are consistent with national policy regarding the extension of buildings in the GB. Neither of the policies, in common with national policy, provide empirical guidance as to what may be considered a disproportionate addition to a building. The exercise of planning judgment is therefore called for.

Guidance is provided in the Council’s Supplementary Planning Document – [name] in the Green Belt (SPD). However, this was adopted in 2008, prior to the Framework’s first publication and prior to the adoption of the Council’s current development plan policies applicable to the GB. Accordingly, it attracts limited weight as a material consideration.

The officer report on the application says: ‘Policy GB1 and the 'Extension in the Green Belt' SPD (sic) sets out that additions to the original dwelling which result in over a 1/3 increase would be considered disproportionate’.

[name] have already mentioned, PP policy GB1 provides no empirical guidance on extensions, but is concerned with protecting the GB’s visual amenities. In so far as it attracts some weight, the SPD does not say that increases over a third of the volume of the original dwelling would be considered disproportionate. Rather, it says that increases above this level are more likely to be considered disproportionate and, as a general rule, the larger the percentage volume increase the less likely the proposal is to be considered acceptable.

Thus, the one third volume increase limit referred to in the SPD as guidance rather than policy is not set in stone as an empirical target above which all extensions are to be considered disproportionate. A further planning judgment or assessment is required. 3 Warwick District Council v Secretary of State for [name], Housing And Communities [2022] EWHC 2145 (Admin)

The Council’s calculations4 on the volume increase involved have not been challenged. Taking account of an earlier modest extension to the original building, the addition of the garden building has involved an increase in excess of 50%. In some circumstances such an increase may be regarded as disproportionate.

However, other relevant matters enter the equation. The garden building is of a low profile and sits comfortably and harmoniously with the original dwelling. The officer report acknowledges that the design is acceptable and contributes and responds to the local context and maintains the character and appearance of the surrounding area, a view that I share. The garden room is also so very well screened by hedges, other vegetation or the extant dwelling that it is inconspicuous and unnoticeable in the public realm. Openness has visual and spatial connotations, and to my mind the development has had little or no impact on the openness of the GB.

The development, accordingly, has not harmed one of the essential characteristics of the GB, it’s openness. Neither has it prejudiced the attainment of any of the five purposes of the GB as set out in the Framework.

I am satisfied, taking all relevant matters into account, notwithstanding the increased volume involved, that the development complies as one of the exceptions under the provisions of paragraph 154(c) of the Framework in that the extension has not resulted in a disproportionate addition over and above the size of the original building.

Accordingly, I intend to allow the appeal. Since the development is substantially complete, none of the Council’s suggested conditions are relevant or necessary. I shall however impose a condition regarding the use and occupancy of the building in the interests of clarity.

I note the references to other development plan policies and other aspects of the Framework, but those to which I have referred are considered the most relevant having regard to the particular circumstances of this case. No other matter is of such strength or significance as to outweigh those considerations that led to my