Appeal 3320685

The appeal is dismissed.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The issues raised by the Council relate only to the two-storey side extension. The conservatory would be similar in size, appearance, and siting to the existing conservatory and would be obscured from public views. The alterations on the western elevation would be minor and would respect the existing appearance of the property. There is no identifiable harm associated with the conservatory or the minor alterations and these elements would not conflict with the development plan. Accordingly, the appeal will focus on the two-storey side extension only.

The Government published a revised version of the National Planning Policy Framework (Framework) on 19 December 2023. The revised national policy is a material consideration. Planning decisions must be made in accordance with the development plan unless material considerations indicate otherwise. In this instance, the issues most relevant to the appeal remain unaffected by the revisions to the Framework. It is not therefore necessary to seek further submissions on the revised Framework, and no party shall be disadvantaged by this action.

The main issue is whether the two-storey side extension would preserve or enhance the character or appearance of the Chislehurst Conservation Area (the CA), including its effect on trees.

The CA derives considerable significance from its relationship between the open spaces, including the extensive commons which form the heart of the CA, and surrounding development. The Supplementary Planning Guidance for Chislehurst Conservation Area (the SPG) identifies that all properties fronting the commons and adjacent main routes, which includes the appeal site, are very important to the character and appearance of Chislehurst. It also emphasises the importance of trees, hedges, and gardens in establishing the feeling of a wooded environment with scattered housing beyond the nearby commons.

The appeal property is on the edge of an area of relatively suburban development, however the site and its neighbour are large properties set in substantial plots. It is a pleasantly characterful property with a predominantly yellow-brick exterior and attractive detailing. The roof has a complex form which is mostly hipped with a gable end on the front-most elevation. The closest neighbouring property, Wayside, is of a similar size but has a slightly different aesthetic due to differences in detailing and external materials. The next closest dwellings are those at the northern end of Manor Park which are bungalows with open frontages.

The appeal property and Wayside are characteristic of the pattern of development and the ‘village-like’ development around the commons and this, along with the design of the appeal property and the trees and hedges on these sites, all contributes positively to the character and appearance of this part of the CA. The Council has also identified the appeal property as a non-designated heritage asset (NDHA), and it derives considerable significance from its architectural detailing.

Saxby’s is a slightly more distant neighbour and is the last of the dwellings on [site address] before the commons. It is a grade II listed building with architectural and historic significance which, as a result, also contributes positively to the significance of the CA. It sits on a spacious plot and is more visually isolated than the appeal site, due to the abundance of trees and vegetation which surround it, including mature trees and hedging between it and the appeal site. This sense of separation and more spacious surroundings mean that the setting of Saxby’s makes a significant contribution to its significance.

The proposed side extension would be more than half the width of the original dwelling at its widest point. Although set back at first floor level, the ground floor would extend close to the front of the dwelling and would extend almost the full depth of the existing building. It would therefore appear as a large and significant addition to the existing property.

A flat roof would not be inherently harmful, particularly given the intention to visually separate the extension from the host dwelling by way of a contemporary design. However, in this instance although the flat roof would be of similar height to the existing eaves, it would sit awkwardly against the traditional form of the existing dwelling. The first-floor element is set away from the main dwelling which creates some articulation and visual separation of the roofs, however it results in a blank link section which would detract from the appearance of the building. The green roofs would not be appreciated as they would be contained within the roof, so while a sustainable feature, these do not contribute significantly to the appearance of the proposal.

The design of the window and door openings seeks to pick up on aspects of the existing dwelling, however the sizes, opening arrangements, glazing layout and arched openings are noticeably different. As a result, they appear overcomplicated and do not achieve the simple, contrasting form which the appellant suggests. They create an uncomfortable relationship with the existing dwelling, drawing attention to the extension rather than complementing the existing building.

The proposed materials would have a contemporary style and high-quality appearance. The dark muted colour would balance well with aspects of the original building and create a clear aesthetic separation. It would also reduce the visual impact of the extensions to some degree, however it would not wholly address the overall bulk.

Accordingly, the overall design, form and scale of the proposal would visually imbalance the property and fail to respect or complement the character and appearance of the existing dwelling. The proposal would be partly screened by retained trees but would still be visible from the public realm close to the site, particularly through the access, as illustrated by the appellant’s images.

The examples provided of properties which have introduced contemporary extensions onto historic buildings have significant differences in their design, size, shape, detailing, and site context. They are not close to the appeal site and are not related to the character of the area around [site address] . They are not therefore directly comparable and carry very little weight which would not outweigh the harm identified.

The previously permitted attached double garage may still be able to be built, however it is not comparable to the current proposal. It would not be as tall, it would have a pitched roof, and it would be set back significantly further from the front of the property than the two-storey side extension. Therefore, it would be considerably less bulky than what is proposed, and more sympathetic in design and scale. Consequently, the potential to build this instead would have less impact on the NDHA and CA than the appeal proposal, and I give it very little weight which would not outweigh the harm identified.

The appellant submitted an [name] and Arboricultural Impact Assessment for the appeal. The Council was given an opportunity to comment on both documents, however, no comments were received. The assessment indicates that one tree close to the rear of the proposal would be removed and that some root pruning would be required to a tree around the front. The loss of one tree at the rear would not be detrimental to either the overall aesthetic value of the trees or the screening they provide.

The retention of the remaining trees is however important to maintain the wooded character of the CA. The proposal would have the potential to impact on the roots of the closest trees, however they are likely to already be constrained by the construction of a wall some years ago. Consequently, with appropriate working methods, site clearance and construction of the proposal are unlikely to put those trees at additional risk of loss or damage. This could be secured by an appropriate planning condition. Therefore, the side extension would not cause harm with regard to trees and would accord with Policy 73 of the London Borough of Bromley Local Plan (January 2019) (the Local Plan) which requires proposals to take particular account of existing trees, which in the interests of visual amenity are considered desirable to be retained.

Although all of the properties mentioned above are detached dwellings and there is space between all of them, for those on Manor Park this space is in some instances very narrow. Along this part of [site address] gaps between dwellings increase as you get closer to the commons, and this space is generally filled with dense vegetation and low-level development such as fencing. In this sense, a comfortable distance between dwellings is a feature of [site address] , Wayside and Saxby’s, rather than open views between each dwelling and its side boundaries.

The side extension would come very close to the eastern side of the site boundary. However, it would remain distant from Saxby’s, so the spatial character of the area would not be harmfully altered. The development would not appear cramped, particularly in the context of Wayside, which extends close to both of its side boundaries. It would not lead to a terracing effect and the existing spatial standards would be protected. For these reasons, the fact that there would not be a minimum 1 metre space from the side boundary as normally required by Local Plan Policy 8 would not harm the character and appearance of the area.

Nevertheless, whilst there would be no harm in relation to gaps between properties or trees, for the reasons set out above the proposed side extension would detract from the appearance of the dwelling. It would therefore diminish its significance as an NDHA and its contribution to the character and appearance of the CA.

Section 72(1) of the Planning (Listed Building and Conservation Areas) Act 1990 requires that special attention is paid to the desirability of preserving or enhancing the character or appearance of conservation areas. The Framework states that great weight should be given to the conservation of designated

The harm would be localised within a small area of the CA, and the extent of the harm to the CA as a whole would be less than substantial in the terms of the Framework. In such situations the Framework requires that this harm should be weighed against the public benefits of the proposal. It also requires that the effect of an application on the significance of a non-designated heritage asset should be taken into account and a balanced judgement reached. There have been no public benefits put forward for the appeal and therefore no justification for the harm identified, which is a matter of considerable weight and importance.

For these reasons, the proposed two-storey side extension would fail to preserve the character and appearance of the Chislehurst Conservation Area. It would conflict with Policies 6, 37, and 41 of the Local Plan which together seek to ensure the scale and form of construction complements the host dwelling, and that development positively contributes to the existing street scene and respects and is sympathetic to heritage assets. Although no harm would arise with regard to trees subject to condition, this would not undermine the harm identified above.

Because of the distance between Saxby’s and the appeal property and a dense collection of trees and other vegetation between them, they cannot be viewed in combination from the public realm and there are no views between the two dwellings. With the main boundary trees retained, the side extension would not affect the setting of Saxby’s. Accordingly, it would comply with Policy 38 of the Local Plan which seeks to preserve the character, appearance, and special interest of statutory listed buildings and ensure there is no harm to their setting.

The absence of an objection is a neutral matter.

It has been suggested that a bunker may extend under part of the proposal. There is a lack of evidence in the submission to verify this suggestion. However, if this were to be the case, it would be a matter for the appellant to address separately.

Subject to condition the extension would not cause harm to trees, however for the reasons above the two-storey side extension would fail to preserve the character and appearance of the CA. Although it would comply with some policies of the development plan, it would not comply with the design and heritage policies, which are matters of considerable importance as set out in the Framework. Therefore, it would not comply with the development plan read as a whole, and there are no material considerations that justify granting permission contrary to the development plan. For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed.

I have considered all the submitted evidence and my representative’s recommendation and I agree with the reasoning set out above. The proposal would conflict with the development plan when read as a whole and there are no material considerations that justify granting planning permission. On that basis the appeal is dismissed.