Appeal 3353130

The appeal is dismissed

The National Planning Policy Framework (the Framework) was revised in December 2024, with further minor updates in February 2025. As the changes do not materially affect the main issues in this case, the parties have not been invited to make further comments.

The appeal site (No 24) lies within the [address] Conservation Area (the CA), and under s72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act), it is my duty to pay special attention to the desirability of preserving or enhancing the character or appearance of the CA.

The Council have made me aware that a new Supplementary Planning Document – [name] & [name] 2025 (the SPD) has been adopted. This supersedes its [name] & Alterations SPD2 Jan 2018 which was adopted at the time the application was assessed. I have sought comments from both parties on the SPD, and this has informed my determination of the appeal.

The proposal is for the demolition of the conservatory and proposed single-storey side to rear extension, roof alterations including the insertion of a rear dormer extension with 3x rooflights, a raised patio with metal balustrade, the conversion of the garage and the replacement of the garage door with a window. The Council has indicated that it has no objection to the conversion of the garage into a habitable room and the works associated with it. Based on the evidence and observations on site, I have no reason to take a different view. The dispute between the parties relates to the insertion of a front rooflight, the single-storey side and rear extension, and the first-floor rear extension, and these shall be the focus of my assessment.

The main issues are: • the effect of the ground floor, 1st floor rear extension and inclusion of a front rooflight on the character and appearance of the host property; and whether the proposed development would preserve or enhance the character or appearance of the CA; • the effect of the proposed raised patio on the living conditions of the occupants of 22 The Crossways (No 22), with particular regard to privacy; and, • the effect of the proposed single-storey rear extension on the living conditions of the occupants of No 22, with regard to outlook.

The appeal site (No 24) is a large detached two-storey dwelling located in a mature and well-established residential area to which an Article 4 Direction applies. The rear elevation of No 24 is recessed in part which creates a step to the flank and rear elevation. Streets are typically characterised by detached and semi-detached properties, set back from the road behind a front garden/driveway, with the gaps between the houses creating a rhythm within the street. No 24, and the houses on the same side, are set slightly higher than the two-storey properties opposite.

In the case of the CA, the special character is derived from predominantly large dwellings set in a hillside location. While many houses exhibit [name] details, all have attractive and largely uncluttered roofs. The imposition of an Article 4 Direction helps preserve these special characteristics. The hillside location allows for fine vistas and results, in the main, in a cascading roofscape which is a distinctive feature of the area and is a positive contribution to the CA. I consider that No 24 has a neutral effect on the CA.

Policy BHC1 of the Brent Local Plan 2019-2041 (Local Plan) relates to Brent's heritage assets and states that proposals should, amongst other matters, seek to avoid harm in the first instance and also sustain or enhance the significance of the heritage asset, its curtilage and setting, respecting and reinforcing the streetscene, frontages and design.

Policy DMP1 of the Local Plan is a general development management policy and seeks, amongst other matters, to ensure that criterion a) the design of development complements the locality, and criterion d) it conserves and, where possible, enhances the significance of heritage assets and its setting.

The Council's Barn Hill Conservation Area Design Guide (the [name]) states, amongst other matters, that roof-lights are not permitted on the front roof slope. In assessing this appeal, I give moderate weight to the guidance contained within the [name].

The proposed development would insert a conservation-style rooflight within the front roof slope. Whilst neither party have directed me to any similar examples, I saw within the surrounding streets a handful of properties which had singular rooflights to the front. The presence of glazing within a predominantly tiled front-facing roof slope created a noticeable difference in the roofing material, with the light reflecting off the glass alongside the muted tiles. This disrupted the uniformity of the roofs and appeared discordant within each street.

The front roof slope of No 24 is experienced within The Crossways and its surroundings, which does not currently appear to have any noticeable rooflights to the front. The proposed rooflight would therefore introduce an incongruent feature that would erode the uniformity of the roofscape. Its insertion would therefore fail to safeguard the character or appearance of No 24 and the localised part of the CA.

The proposal would project approximately 4.5 metres from the rear of the property and would extend across the whole elevation of the dwelling, and part of both side additions, whilst retaining a gap of approximately 1 metre to each boundary. At its highest, its mono-pitched roof would sit approximately beneath the window cill of the upper floor.

I acknowledge that the proposed extension would be to the rear, however, this does not obviate the obligation to ensure that it would be well designed. Even if the overall height of the proposal would be lower than the height set out in the SPD, it would be significantly taller than the existing conservatory and would likely be higher than the roofs of the existing side extensions. The height, together with the width and depth of the proposal, would add considerable bulk to the rear. This would be discernible from the rear windows of other properties in the immediate area, and from the street through the gaps between neighbouring properties. This proposal would therefore form an unsympathetic addition to No 24 and would fail to preserve or enhance the character or appearance of the CA when considered as a whole.

The proposal would continue the existing flank and rear elevations, infilling the current recessed area. This would result in a crown roof above, which would be visible from within The Crossways and from properties to the rear.

The Council refers to its [name], highlighting that two-storey rear extensions are generally prohibited and that the infill would lead to a more uniformed elevation and would not respect the well-executed architectural detailing. However, I saw variation in both the roof design and rear elevations of properties within The Crossways, which included the immediate neighbour, No 26. [name] note this property is of a different design to the appeal site, it nevertheless forms part of the immediate character and, as such, is material in my assessment.

I acknowledge that the proposal would erode the stepped approach to the rear and incorporate a crown where there is none at present. However, whilst the Council has a general cautious approach to rear extensions, the proposal would result in a modest increase in floor area. Furthermore, it would have a similar ridge line and roof pitch as the existing roof and retain the chimney stacks.

Given the modest increase in floor area and variation in roof design within The Crossways, I do not regard the creation of the crown or two-storey rear extension as being unduly large, or that this form of roof construction would look out of keeping in relation to No 24 or the CA.

The Framework advises that when considering the impact of development on the significance of designated heritage assets, great weight should be given to their conservation. It advises that significance can be harmed or lost through the alteration or destruction of those assets or from development within their setting, and that this should have a clear and convincing justification. I find the harm to the heritage asset to be ‘less than substantial’ in the context of the CA. Nevertheless, the harm is of considerable importance and weight. Under such circumstances, Paragraph 215 advises that this harm should be weighed against the public benefits of the proposal.

In terms of public benefits, the Planning Practice Guidance advises that they should be of a nature or scale to be of benefit to the public at large and not just a private benefit. As the proposed development would provide additional accommodation associated with No 24, this amounts to a private benefit and, as such, does not weigh against the harm I have identified to the significance of the designated heritage asset.

Whilst the proposed first floor rear extension would be acceptable, I find that the proposed front rooflight and single storey rear extension would harm the character and appearance of the host property and the CA, and would therefore fail to preserve or enhance the character or appearance of the CA.

Accordingly, the proposed development would fail to meet the requirements of the Act. There would also be conflict with Policies DMP1 and BHC1 of the Local Plan, insofar as they seek to ensure proposals preserve or enhance the character or appearance of the CA. There would also be conflict with the [name], insofar as it seeks to preserve or enhance those qualities of the CA. The proposal would also be contrary to the provisions of the Framework in relation to heritage assets.

Ground levels within the rear garden of No [address] towards properties to the rear on [address]. The boundary treatment between the appeal site and No 22 rises to follow ground levels. No 22 is set on a slight axis to the appeal property and, from my observations, has a single-storey element set close to the boundary. Whilst the main ground floor rear wall of No 22 is along a similar line as the main rear wall to No 24, its upper floor is set off the shared boundary and is stepped. Windows within the rear elevation predominantly provide views of its own garden.

The proposed raised patio would extend approximately 1.2 metres beyond the rear wall of the proposed single-storey rear extension and would extend across the whole rear elevation and up to the shared boundary with No 22.

Plans submitted in support of the appeal do not show the height of the boundary in relation to the proposal, the garden or the rear elevation of No 22. Even if there may already be a sense of overlooking when within the garden, and the depth of the proposed terrace would be modest, I have nothing to demonstrate that the use of the terrace would not enable direct views into those habitable rooms or the garden of No

I have taken the appellant's suggestion of screening as mitigation into consideration, however, I have not been provided with any details. Given the uncertainty with regard to the height of the existing boundary to No 24, ground levels within No 22, and the proximity of the terrace to the boundary, the use of a condition would not be reasonable in this case. Consequently, this would have a harmful effect on the privacy of the occupiers of No 22.

The Decision Notice states that the proposed single-storey rear extension would have an “unacceptable impact on the neighbouring amenity of No 22”. However, the Council’s officer report contends that, given this element would be set in by 1 metre, the proposal would have limited impact on neighbouring amenity. Given the contradictions in the evidence, I have assessed the proposal based on submitted plans and observations on site.

The proposal would project approximately 4.5 metres from the main rear wall of No 24 and would project significantly beyond the rear of No 22. Whilst the proposal would undoubtedly be visible from No 22, based on the evidence and observations on site, any views from the rear would be oblique, with the extension largely obscured by the boundary. Given this, I do not consider that the proposal would be as harmful as the Council contends.

I conclude that whilst I have found the proposed single storey rear extension would provide adequate living conditions with regard to outlook for the occupants of No 22, this would not be the case with respect to the proposed raised patio and privacy. Accordingly, the proposed development conflicts with Policy DMP1 of the Brent Local Plan, which seeks to ensure development provides high levels of internal and external amenity.

Even if the Council are silent with regard to No 22 and any effect of the proposed development on daylight, this does not outweigh the harm I have identified above.

I recognise that the proposal would provide additional living accommodation for the occupants within No 24, however, the benefits of doing so would not outweigh the harm that it would cause to the character or appearance of the CA or the living conditions of the existing occupants within No 22.

For the reasons given above, I find that the proposal conflicts with the development plan taken as a whole, and material considerations do not indicate the decision should be made other than in accordance with it.

I conclude that the appeal should be dismissed.