Appeal 3352298

The appeal is allowed and planning permission is granted for erection of single storey front extension to existing dwelling at [site address] , [site address] , Downe, Orpington, Bromley [postcode] in accordance with the terms of the application, [name]/24/01828/FULL6, 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 5996-23-PL001 P1; 5996-23-PL002 P1; 5996-23-PL003 P1; 5996-23-PL004 P1.

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

An application for costs was made by [name] against the decision of the Council of the London Borough of Bromley. This application is the subject of a separate decision.

[name] 2024, government published a revised National Planning Policy Framework (the Framework). The written submissions pre-date the publication of the revised Framework which made certain changes to national Green Belt policy.

However, matters relevant to this appeal have not materially changed from the Framework’s previous iteration, notably, the fundamental aims of Green Belt policy, essential characteristics of the Green Belt, and the five Green Belt purposes, as described by Framework paragraphs 142 and 143. Furthermore, Framework paragraph 154(c) maintains that 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 is not inappropriate development. Therefore, in this circumstance it was not necessary to consult the parties on the implications of the revised Framework.

The main issue in this appeal is whether the proposed development would be inappropriate development in the Green Belt, having regard to the Framework and relevant development plan policies.

The appeal site comprises a detached dwelling and its garden. It is set back behind dwellings which front onto the highway, and is served by a private access road. Beyond the site are fields and paddocks. The site is in a rural location within the Metropolitan Green Belt.

As stated at paragraph 142 of the Framework, the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open.

Policy 49 of the Bromley Local Plan 2019 (BLP) resists inappropriate development in the Green Belt unless the harm is clearly outweighed by very special circumstances. Policy 49 identifies certain forms of development that are not considered to be inappropriate, including the extension or alteration of a building that does not result in disproportionate additions over and above the size of the original building. This requirement reflects paragraph 154(c) of the Framework.

BLP Policy 51 provides additional criteria for the extension and alteration of dwellings in the Green Belt.

The proposal would result in a 9.4% net increase in external floor area. Since the increase would be less than 10% of the external floor area of the original dwellinghouse, the parties agree the proposed extension would comply with criterion (a) of Policy 51.

However, Policy 51 also requires that (b) the size, siting, materials and design do not harm visual amenities or the open or rural character of the locality; and (c) the development does not result in a significant detrimental change in the overall form, bulk or character of the original dwellinghouse. In addition, [name] 6 and 37 provide design criteria relevant to the proposed residential extension.

The proposed extension would be single storey with a mono pitched roof. The roof plane would slope at a shallow angle. The design would therefore minimise the overall size, and the proposed extension would be modest in scale.

The appeal property is a chalet-style dwelling and has large, prominent, front dormers. It is of recent construction, having replaced a former agricultural building. Through its form and materials, the design of the dwelling emulates the traditional appearance of a barn. However, the dwelling’s design incorporates modern features, such as extensive glazing at the front elevation.

The proposed extension would have a contemporary appearance. However, it would utilise materials to match the existing dwelling, including its windows which would provide a continuation of the glazing at the front elevation.

In addition to being distant from the highway and beyond existing built form, the appeal property is oriented away from the street and neighbouring dwellings and faces into its large, private garden. The proposed extension would not therefore be visible from the highway and there is visual separation from surrounding dwellings.

The appeal property is set back in the site. The proposed extension would be to one side of the front elevation, away from boundaries and would project into an area of private garden. The plot is enclosed by a mix of boundary treatments including a solid gate, fences, and hedges. This provides clear separation from surrounding paddocks and agricultural land and the proposal would not encroach into countryside.

A public right of way (PRoW) runs along the vehicular access and continues past the site. Beyond the site, the PRoW is enclosed by dense vegetation which would prevents long distance views of the proposed extension. On passing the site, there would be glimpsed views through boundary vegetation. However, the proposed extension would be viewed against the contemporary features of the host dwelling’s front elevation and would not be viewed in the context of neighbouring dwellings. Therefore, the proposal would not be visually prominent and would not detract from the rural character of the area.

Through its scale and form, the proposed extension would appear subservient to the host dwelling and would not add harmful bulk to the dwelling’s form. The proposed extension would be of limited visual prominence from public vantage points. The original form of the building would be readily discernible, and the proposed extension would not significantly alter the dwelling’s character.

For these reasons, the proposal would not harm visual amenities or the open or rural character of the locality and would not result in a significant detrimental change in the overall form, bulk or character of the original dwellinghouse. The proposal would therefore satisfy criteria (a)-(c) of BLP Policy 51. Therefore, the proposal would not result in a disproportionate addition to the appeal property and would not constitute inappropriate development within the Green Belt.

The proposal would therefore comply with [name] 49 and 51, and Policy G2 of The London Plan 2021, which together protects the Green Belt from incremental harm from inappropriate development.

In addition, the proposal would comply with [name] 6 and 37 which require proposals be of a high standard of design and layout, and requires the scale, form and materials of construction respect or complement the host dwelling and be compatible with development in the surrounding area.

To the northwest of the appeal property is [name], a two-storey, [name] listed building, which was constructed in the 18th century. The building has a tiled roof, two gabled dormers, casement windows, and is faced with knapped flints with vertical strips of red brick-like quoins. The building’s significance is therefore derived from its historic and architectural interest.

The appeal site was formerly connected with the listed building. However, boundary treatments provide clear visual separation between the appeal property and listed building. The proposed extension would not be visible from the public highway, and therefore would not affect views of the listed building from the street.

From the PRoW to the south, the listed building is only partly visible above its boundary hedge. In addition, as discussed above, the proposed extension would be modest in scale, would be in keeping with the host property’s character, and would be well-screened by boundary treatments. Therefore, the proposed development would not have an adverse impact on views of the listed building from the PRoW.

The proposal would therefore preserve the building, its setting, and features of special architectural or historic interest, and would thus comply with the Planning (Listed Buildings and Conservation Areas) Act 1990.

In addition to the standard time limit for implementation, in the interests of certainty I have attached a condition specifying the approved plans. To maintain the character and appearance of the area, I have included a condition requiring external materials match the existing building.

As indicated in the committee report, the proposal would not be subject to the requirements of the national mandatory [name]. The proposed extension would have a small footprint and would be sited on an area that is presently a paved patio and therefore would not result in a loss of habitat. The committee report suggests there would be opportunity for biodiversity enhancements including new planting and landscaping within the site. However, I have not included such a condition since it is unclear why such enhancements would be necessary to make the development acceptable in planning terms.

The proposed extension’s roof surface would be inaccessible from the dwelling. Therefore, a condition to prevent use as a balcony/terrace is not necessary.

For the reasons given above, having regard to the development plan taken as a whole and all other relevant material considerations, I conclude the appeal should be allowed.