Appeal 3346385

The appeal is dismissed insofar as it relates to the part first floor side extension.

The appeal is allowed insofar as it relates to the single storey rear extension and conversion of garage to habitable use; and planning permission is granted for a single storey rear extension and conversion of garage to habitable use at 5 [name], [address], [name] [postcode] in accordance with application Ref: 53203/APP/2024/63 and the following conditions:

The single storey rear extension and conversion of the garage shall take place no later than three (3) years from the date of this decision;

The single storey rear extension and conversion of the garage shall be undertaken in accordance with approved plan: [name] and [name]; [name]; 3LC/06112023/REV-A; Dated 06 November 2023.

The single storey rear extension and conversion of the garage shall be constructed of materials that match the existing dwelling in terms of colour, material, size and texture.

I have taken the description of the development from the Council’s Decision Notice as this more accurately describes the individual elements requiring planning consent.

The main issue is the effect of the proposed development upon the existing building and the character and appearance of the locality; with special attention to the Harefield Village Conservation Area (CA). Appeal Decision: APP/R5510/D/24/3346385

Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, in respect of development affecting conservation areas, states that special attention shall be paid to the desirability of preserving or enhancing the character and/or appearance of the area.

Whilst no CA appraisal has been submitted with this appeal, the appeal documents together with my observations on my site visit illustrate that much of the significance of the CA comes from the associations and experiences of the buildings, spaces and the surrounding rural hinterland. The CA includes the large hospital site to the north, the main high street and surrounding expansions of the village. Within the area there is a clear emphasis on vegetation and spaces in and around dwellings which assist in emphasising a spacious and semi-rural feeling and a relationship with the surrounding hinterland. These are some of the elements that reinforce the qualities that contribute to local distinctiveness and the character and appearance of the area.

The appeal site is part of a later infill development that consists of detached dwellings formed around a narrow winding cul-de-sac. The group of dwellings maintain a homogenous, replicative and functional design with the two storey main component with pitched roof fronting the street with small feature gable to the front façade. A tiled porch runs across the front of the dwellings onto the single storey garage to the side of the dwelling. The single storey side garage enables a visual break between the dwellings where the tops of trees to the rear can be seen which adds a positive vegetated element to the character and appearance of the area. The materials are also largely consistent and comprise of light cream brick with red brick detailing, some of the dwellings have a rendered façade, with concrete tiles. Unfortunately many of the front gardens have been hardscaped to allow for vehicular parking which is a negative aspect of the character, however open front gardens and the dominance of vegetation and spaces in and around buildings assists in reinforcing the positive qualities of the locality.

In undertaking extensions and alterations to existing dwellings, the Hillingdon Local Plan – [name] (LPSP) Policies BE1 and Hillingdon Local Plan Development Management Policies (LPDM) Policies DMHB11 and DMHB12 are all design led policies which seek that development achieve a number of design principles such as being integrated with the surrounding area, appreciate scale, heigh, massing, building lines and gaps between structures, amongst others. LPSP Policy HE1 is specific to heritage assets and seeks to ensure that development conserves and enhances Hillingdon’s wider historic landscape. LPDM Policy DMHB 4 is specific to Conservation Areas and seeks that development preserve and enhance the significance, including their setting.

The proposed extension would fill much of the gap over the single storey garage and have an awkward juxtaposition when seen in the context of surrounding buildings, removing a positive influence of the visual gap and giving an almost complete wall of built form from the appeal dwelling to the neighbouring dwelling. [name] appreciate explanations as to the design such as the setting back of the extension from the front façade and lowering the ridge in order to reduce visual bulk, this is unsuccessful. Further details shown in the [name] of Case which show the masking of the trees behind are further evidence of the inappropriateness of this form of development that erodes visual gaps which are Appeal Decision: APP/R5510/D/24/3346385 important to the significance of the conservation area in this location. The removal of positive aspects such as the visual gap between the dwelling would also be further detrimental to the character and appearance of the locality, and would be unlike anything in the surrounding locality. I am unclear of the reasoning of the Appellant that the extension would be in a ‘discreet location’ as Section 72 of the PLBCA does not seek to apply the duty differently on where the extension is located, or whether it is within the private or public realm; the same duty remains.

I appreciate examples of [address] where a side extension was allowed in

Despite the application being a long time ago under a different policy position, the dwelling is not within the same street scene as the appeal site, with there being no dwelling adjacent where there is no characteristic visual gap between dwellings. As such this dwelling does not feature the characteristic and repetitive gap between the dwellings and is therefore not helpful in demonstrating the appropriateness of the appeal proposal. I have also seen examples at Nos.3 and [address] as specified by the Appellant, however these also contain different planning considerations around the visual gaps in and around dwellings and are not analogous to the appeal site. The proposed first floor extension appears to have been developed in isolation of the context and character and appearance of the area, and for this reason would be detrimental to the character and appearance of the existing dwelling and of the locality.

In conclusion of this matter, the proposed extension would not be an appropriate architectural response which would reinforce the positive qualities of the building and the locality. The loss of visual gap, removal of positive features and the poor relationship of the extension to the existing building would be detrimental to the existing building and to the greater locality. The extension would therefore be contrary to LPSP Policy BE1 and [name] DMHB4, DMHB11 and DMHB12 as described previously.

Although serious, the harm to the heritage asset in this case would be ‘less than substantial,’ within the meaning of the term in paragraph 208 of the Framework. Paragraph 206 of the Framework states that any harm to, or loss of, the significance of a designated heritage asset requires clear and convincing justification. Paragraph 208 of the Framework requires that, where a proposal would lead to less than substantial harm, the harm should be weighed against the public benefits of the proposal.

The Appellant has not suggested public benefits of the scheme, however there would be economic benefits in terms of short term employment in the construction of the extension, and allows the residents to remain in the area; allowing additional accommodation for the occupants and making efficient use of land. These benefits may also be present in a scheme that is more compatible with the policies of the Development Plan and therefore attracts limited weight. These benefits are not sufficient to outweigh the harm caused to the CA, in which I attach great weight.

I therefore find that the public benefits arising from the proposed development would not outweigh the harm I have identified. The scheme therefore conflicts with the Framework, which directs, at paragraph 205, ‘that great weight should be given to the asset’s conservation ... irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to their significance.’ Appeal Decision: APP/R5510/D/24/3346385

For these reasons, and having considered all matters raised in evidence and from what I saw during my site visit, I conclude that the appeal should be allowed and planning permission granted insofar as it relates to elements described in Paragraph 2 above, subject to the conditions as detailed in this letter. As the rear extension and conversion of the garage is both physically and functionally severable, I consider a split decision would be a logical outcome.

I refer to the suggested conditions specified by the Council in their Statement of Case, if the appeal was to be allowed and have considered them in accordance with the Planning Practice Guidance (PPG).

Suggested conditions 1 and 2 are standard conditions which set the standard time limit and approved plans which are necessary for the avoidance of doubt and in the interests of proper planning. Suggested condition 3 is a condition requiring the scheme utilise matching materials as described in the application documents and to the existing dwelling. This is considered necessary to ensure that the appearance of the extensions are compatible with the existing dwelling and the character and appearance of the CA.