Appeal 6005862

The appeal is dismissed.

An application for an award of costs was made by [name] against the Council of the London Borough of Hounslow. An application for an award of costs was also made by the Council of the London Borough of Hounslow against Urbane London Ltd. These applications are the subject of separate decisions.

As part of the appeal the appellant submitted amended plans drawing nos 24001- GFA-X-LG-DR-A-11200 P.08, 24001-GFA-X-01-DR-A-11202 P.09, 24001-[name]-11203 P.09, 24001-GFA-X-ZZ-DR-A-12201 P.05, 24001-[name]-12202 P.06, 24001-GFA-X-ZZ-DR-A-13201 P.05, 24001-GFA-X-ZZ-DR-A- 13202 P.04, 24001-GFA-X-00-DR-A-11201 P.10, 24001-GFA-X-ZZ-DR-A-12200 P.07, a Daylight and [name] dated 17 February 2026, an [name] and [name] dated 17 February 2026, Design and [name] dated 18 February 2026 and [name] dated 19 February 2026.

These amended plans replaced the proposed roof terrace with a green roof (accessed for maintenance only and included the removal of the proposed glass balustrade), the introduction of a 250mm setback of the building line on the single storey element of the northern elevation and the relocation of the Air Source Heat Pump (ASHP) from the roof to the ground floor. The appellant considers that these amendments are only minor changes, which were discussed informally with the Council prior to the decision being made.

I have considered the amended plans with regard to the judgement of Holborn Studios Ltd v The Council of the London Borough of Hackney [2017] EWHC 2823 (Admin). In terms of the substantive test, I find that the proposed amendments would not be a fundamental change to the proposal. In terms of the procedural test, given that interested parties were aware of the amended scheme, through both the appeal and the submission of a revised application, I do not consider that they would be prejudiced if I determined this appeal on the basis of the proposed amendments. Consequently, I have accepted this additional evidence as part of the appeal and the Hearing was conducted on this basis.

The Written Ministerial Statement of 23 October 2025 set out new measures to increase housebuilding in London. This included proposals to withdraw the relevant sections of the Housing Design Standards London Plan Guidance 2023. Subsequent consultation has taken place on a draft ‘Support for Housebuilding’ London Plan Guidance which included greater flexibility in the application of dual aspect requirements, this consultation closed on 22 January 2026. On the basis of these proposed changes and the [name] and Sunlight Assessment submitted as part of the appeal the Council is satisfied that this has resolved concerns relating to the quality of the new accommodation and the second reason for refusal has been withdrawn. The latest position is set out in the signed Statement of [name] dated 7 May 2026.

Therefore, based on the evidence provided the main issues are: • the effect of the proposed development on the living conditions of neighbouring residents with regard to daylight, outlook, noise, privacy and sunlight; and • whether the proposed development would provide adequate accommodation for future occupants with regard to fire safety.

Paragraph 130 c) of the National Planning Policy Framework (the Framework) states that when considering applications for housing, authorities should take a flexible approach in applying policies or guidance relating to daylight and sunlight, where they would otherwise inhibit making efficient use of a site (as long as the resulting scheme would provide acceptable living standards). Policy CC2 of the London Borough of Hounslow Local Plan 2015-2030 (2015) (LP) states that proposals should function well in themselves and in their effect on surrounding areas and have a positive impact on the amenity of current and future residents.

The appeal site is in a suburban area with development comprising rows of dwellings with front and rear gardens which gives it a spacious, regular character. The site adjoins No [address], which has been converted into flats and has windows on the rear elevation, which face onto the appeal site at ground, first and roof level. The site also adjoins [address] which has windows on its side elevation facing towards the appeal site and the rear garden of [address], both of which are single dwellings. Although the proposal would be subservient in height to the adjoining dwellings it would result in significant increased massing in comparison to the built form of the existing garages.

A Daylight and [name] Report1 was submitted as part of the application and assessed 32 windows serving 15 rooms in three neighbouring properties for daylight. The report concluded that 31 out of 32 windows would achieve the [name] (BRE) guide levels for daylight for [name] (VSC) and 14 out of 15 for [name] (NSL). The window which did not satisfy the guide levels serves a bedroom in the ground floor flat at No 65. [name] is less than 27% its former value the area lit by the window is more likely to appear gloomy and electric lighting will be needed more of the time. The proposed development would reduce VSC to this window from 32.6% to 16%.

An updated report2 was submitted with the appeal, which considered the proposed 250mm setback of the building line on the northern elevation as shown on the amended plans. Based on this revision the report concluded that 7 of the 8 windows tested at No 65 satisfied BRE guidelines with regards to VSC with 6 of the 7 also satisfying NSL. Therefore, the updated report concluded that even with the proposed setback of the northern elevation, the VSC of the ground floor bedroom window of the flat at No 65 would still be reduced to 20.5% which is below the 27% threshold where there would be a noticeable reduction in the levels of daylight.

During my site visit I was provided with access to the ground floor flat at No 65. This flat has an open plan kitchen/living area served by full height windows to the rear, which face towards the appeal site and two large windows facing towards [address]. The bedroom served by the window which doesn’t meet the guidelines faces towards the appeal site and is the second, smaller bedroom. I observed that there was a small tree in the rear garden close to the bedroom window and other vegetation which has grown above the fence line, which also screens the window. Whilst this vegetation could be removed at any time, I note that the Daylight and [name] disregarded the presence of this vegetation in the assessment.

The bedroom window of the ground floor flat faces onto the side elevation of the single storey garage block and therefore due to its proximity receives less daylight than other rooms where windows are positioned further away from this building. The proposed dwelling would have a larger footprint and be greater in height than the existing garage block, and the side elevation would run along a greater extent of the boundary with No 65. Therefore, in my view the size, scale and proximity of the proposed dwelling would materially reduce the amount of daylight entering the bedroom, which is substantiated by the submitted technical evidence.

The appellant puts forward that the remaining VSC serving the ground floor bedroom window is high for a dense urban location such as the appeal site and would still provide a good level of residual daylight to the bedroom. Moreover, in order to achieve a meaningful increase in VSC to the bedroom window approximately half of the first-floor element would need to be removed. 1 Undertaken by dpr dated 11 September 2025 2 Undertaken by dpr dated 17 February 2026

[name] recognise that bedrooms are not the primary living space, they also serve as spaces for studying, home working and children’s play. Whilst this ground floor bedroom is not currently used for working from home, the appellant cannot be sure how future occupants may choose to use this room and therefore in my view it should not be afforded unacceptable levels of daylight. The BRE guidelines are not mandatory and should be interpretated flexibly. Notwithstanding the suburban location of the appeal site, based on my observations, the height and depth of the proposed dwelling and its proximity to the window of the ground floor flat at No 65 would result in unacceptable harm to the living conditions of existing and future occupants.

The appellant suggests that the Council has acted inconsistently as it has granted permission where VSC at neighbouring properties would be reduced below 27%. I note that the [name] scheme3 was a variation of condition proposal which would deliver 111 dwellings where the VSC would range from 8.73% to 10.21% and the NSL results showed good overall levels of retained sky visibility. The Ham Wharf scheme4 was for 56 flats where some windows would not satisfy BRE criteria through the VSC test, however all but one would meet the daylight distribution test and as such would perform well as a whole. The scheme at 27-1053 [name] Road5 was for 856 homes where although adverse impacts on daylight were identified the majority of windows and rooms assessed would continue to meet the BRE guidelines and there are existing issues such as balconies, flank walls and the position of the M4 flyover. In the Griffin Park scheme6 for 149 dwellings 99% of the windows achieved the BRE guidance. In the scheme at 389 [name] Road7 for 394 shared living rooms and 23 dwellings, there would be a 41% loss to 5 bedrooms and 30% loss to a further 13 rooms, however this was considered acceptable due to the constraints of the site and provision of social rent units.

The examples outlined above are of a different scale to the appeal proposal for a single dwelling, some distance from the appeal site and have different site contexts and constraints. Therefore, I am not satisfied that they are directly comparable to the appeal scheme. In any event I have considered the proposal on its own merits and identified harm for the reasons given.

I have also been referred to the planning application which was approved for a single storey side infill extension at [address]. In this case the existing vegetation was considered as a mitigating factor. However, this proposal was stepped back in height and from the side boundary of No 65 and as such is not comparable to the proposed development which would be directly in front of its rear windows and therefore would have different impact.

By reason of its increased massing and scale the proposed development would result in a harmful reduction in daylight to the bedroom of the ground floor [address], thereby harming the living conditions of existing and future occupants. 3 P/2025/2496 4 P/2023/3014 5 P/2023/3208 6 P/2024/3503 7 P/2025/0794

The Hounslow Character, Sustainability and Design Codes Supplementary Planning Document (2024) states that the introduction of new built form into street facing garage sites can sometimes create a negative sense of enclosure and proposals should maintain a sense of openness. It goes onto say that the height of development on street facing garage sites should be subservient to the host building plot and neighbouring dwellings.

The appeal site comprises six single garages located between [address] and [address], both of which comprise two storey semi-detached properties with roof accommodation. The existing garages extend along the boundary with the residential garden of [address], rising just above its low-level boundary wall and trellis treatment. This garden is further enclosed by the single storey extension attached to the side elevation of [address]. Its boundary with No 61 comprises landscaping of limited height. Owing to the garage block being single storey, views are currently afforded from the garden towards the upper parts of buildings on the opposite side of [address]. [address], the landscaping in rear gardens can be seen above the garages which provides a notable sense of openness between the rows of buildings.

The proposed dwelling would be built right along the boundary of adjoining properties. Notwithstanding the modest setback of the northern elevation, its rear wall would run along almost the entire length of the boundary of the garden of No 63 at a height of approximately 6.8m. This would result in a visually dominant and overbearing form of development in comparison to the existing single storey garage block. This would significantly diminish the open aspect of the rear garden of No 63 and increase the sense of enclosure of the outdoor space.

The ground floor flat of No 65 has a decked area leading from its patio doors. Steps lead down from the decked area to a small garden space that stretches across the back of the building. Despite the vegetation growing over the fence, from the patio doors and the decking you can see above the garages towards the side elevation of [address]. Although the first-floor element of the proposed dwelling would be stepped back from the ground floor element, the gap between it and No 65 would be less than 4m distance and it would extend along more of its shared boundary than the existing garage block. Given its proximity and height, the side elevation of the proposed dwelling and introduction of a blank wall at first floor level would reduce the outlook of the ground floor flat and increase the sense of enclosure within the garden space.

Therefore, the proposed development would result in unacceptable harm to the living conditions of the residents of the ground floor flat of 65 and [address] with regards to outlook.

As part of the amended plans the ASHP has been relocated from the roof to the ground floor, adjoining the boundary with [address]. Although not included in the Council’s reasons for refusal, its [name] refers to Criteria (i) of Local Plan Policy EQ5 which requires proposals to demonstrate that new plant and machinery should not harm the amenity of neighbouring properties and generate noise at least 10dB below the background noise levels.

A Noise Report8 was submitted as part of the appeal. The closest sensitive receiver is the residential window of [address] located approximately 5m from the proposed location of the ASHP. Although a specific ASHP unit has not yet been chosen, the [name] states that typical noise levels of ASHPs range from 40-60dBA which would be reduced by 14dBA at a distance of 5m. Whilst the [name] does not include an assessment of the background noise levels, I accept that as put forward by the appellant at the hearing, that noise levels of ASHP’s are largely dependent on the type of enclosure. I am therefore satisfied that subject to an appropriate designed enclosure, which could be controlled by condition, that there would be no unacceptable harm to the living conditions of neighbouring residents. On this basis, the proposal would not result in unacceptable harm to neighbouring residents with regard to noise.

Plans submitted with the application included a roof terrace, however this has been replaced with a green roof in the amended plans, and the glass balustrade has been removed. Although third parties maintain their concerns that the submitted plans show that the roof would be accessed for maintenance purposes, the Council considers that this can be appropriately controlled through condition. I agree that this would provide appropriate control in order to prevent unacceptable harm to neighbouring residents with regard to privacy.

With regard to sunlight, the updated Daylight and [name] concluded that 77% of the rear garden of No 63 would satisfy the BRE guidelines for sun on ground. I observed that the garden is long and due to its orientation, sections of the garden would still have good levels of sunlight through parts of the day, and the proposal would not result in significant overshadowing. Therefore, there would be no unacceptable harm to the living conditions of neighbouring residents with regards to sunlight.

Drawing these matters together, the scale, height and proximity of the proposed dwelling would materially reduce the level of daylight to the bedroom of the ground floor flat of No 65. This, in combination with the increased sense of enclosure of its outdoor amenity area would result in unacceptable harm to the living conditions of its residents with regards to daylight and outlook. Furthermore, the proposal would lead to the increased enclosure of the garden of No 63, thereby resulting in unacceptable harm to its residents with regards to outlook. The proposed development thereby conflicts with Policy D4 of the London Plan and Policies CC1, CC2, CC4 and SC7 of the LP which amongst other things seek to ensure that proposals do not harm the amenity of neighbouring residents, maintain the character and amenity of private spaces, including rear gardens, do not result in an unacceptable sense of enclosure and have a positive impact on the amenity of current and future residents. 8 Undertaken by Acoustics dated 19 February 2026

[name] of Policy D12 of the London Plan states that in the interest of fire safety and to ensure the safety of all building users, all development proposals must achieve the highest standards of fire safety. [name] of this policy requires that a [name] should be submitted for all major development proposals. The main parties agree that [name] of the policy does not apply. However, [name] still needs to be met.

The submitted drawings show that the lower garden area would have a ladder escape and as the site faces onto [address] I observed that there is space outside the proposed dwelling for fire appliances to be positioned. However, the submitted information does not include details of how the proposed dwelling would be safely evacuated in the event of a fire or how it would be constructed to prevent the spread of fire. It therefore does not include sufficient information to address all of the criteria in [name] of Policy D12.

The supporting text of Policy D12 states that the fire safety of developments should be considered from the outset and before the building control stage. Therefore, based on the submitted evidence I cannot be satisfied that the proposal would provide adequate accommodation for future occupants with regards to fire safety. The proposal thereby conflicts with Policy D12 of the London Plan, which seeks to ensure that all development proposals achieve the highest standards of fire safety.

Concerns have been raised in relation to anti-social behaviour due to the disused nature of the appeal site but there is no substantive evidence before me to suggest that other security deterrents have been explored. Nonetheless this does not outweigh the harm that I have identified above.

I also note that the owner of No 65 does not object to the proposal, however the absence of objection does not in itself render the scheme acceptable for existing and future occupants.

The proposed development would provide one new family dwelling which would make a minor but nevertheless important contribution to the local housing supply. It would also regenerate a disused garage site, in an accessible location and would be of energy efficient design. Additionally, the proposed landscaping would enhance the biodiversity value of the site. However, it would result in unacceptable harm to the living conditions of neighbouring residents with regards to daylight and outlook and has not provided satisfactory information relating to fire safety. These harms are not outweighed by the benefits which I have identified and therefore, material considerations do not indicate that the appeal should be decided other than in accordance with the development plan.

Accordingly, for the reasons given above the appeal should be dismissed.