250 Gunnersbury Avenue, LONDON, W4 5QB

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Site visit made on 24 February 2023 by S Edwards MA MATCP MRTPI an Inspector appointed by the Secretary of State Decision date: 11 September 2023 Appeal Ref: APP/F5540/W/22/3296413 250 Gunnersbury Avenue, London W4 5QB • The appeal is made under section 78 of the Town and Country Planning Act 1990 against a refusal to grant approval required under Article 3(1) and Schedule 2, Part 20, Class AA of the Town and Country Planning (General Permitted Development) Order (England) Order 2015 (as amended). • The appeal is made by Abrigo Estates Ltd against the decision of the Council of the London Borough of Hounslow. • The application Ref 00535/250/PA1, dated 1 November 2021, was refused by notice dated 21 January 2022. • The development proposed is upward extension of existing commercial building to provide 2 additional storeys to provide 8 residential flats (C3). Decision 1. The appeal is dismissed. Preliminary Matters 2.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Schedule 2, Part 20, Class AA of the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended (the GPDO), permits development consisting of works for the construction of up to two additional storeys of new dwellinghouses immediately above the topmost storey on a detached building. 3. As detailed within the GPDO1, development under Class AA is permitted subject to the condition that before beginning the development, the developer must apply to the Local Planning Authority for prior approval. The Local Planning Authority may refuse the application where it considers that the proposal does not comply with the limitations or restrictions that are applicable to such permitted development. 4. The provisions of the GPDO require the Local Planning Authority to assess the development proposed solely on the basis of a limited number of considerations. Furthermore, development plan policies and the National Planning Policy Framework (the Framework) can be considered relevant in prior approval cases, but only insofar as they relate to the matters and only as evidence to support the planning judgment to be made. I have proceeded on this basis. 5.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision There is another appeal (APP/F5540/W/22/3297229) on this site which relates to a different proposal, and will therefore be the subject of a separate decision. 1 Part 20, Class AA, paragraph AA.2. https://www.gov.uk/planning-inspectorate

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision There is another appeal (APP/F5540/W/22/3297229) on this site which relates to a different proposal, and will therefore be the subject of a separate decision. 1 Part 20, Class AA, paragraph AA.2. https://www.gov.uk/planning-inspectorate

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Appeal Decision APP/F5540/W/22/3296413 Main Issues 6. The main issues are: • The effect of the proposal on the external appearance of the building; • Whether the proposal would provide satisfactory living conditions for future occupiers of the development, with particular regard to natural light; and • The effect of the proposal on the objectives of the area’s classification as a Locally Significant Industrial Area. Reasons External appearance 7. The appeal site comprises a three-storey purpose-built office block, which is sited prominently on the eastern side of Gunnersbury Avenue. With its concrete frame and red brick outer layout, the existing block is characterised by its brutalist and rather utilitarian appearance, whilst the regimental approach of the windows and the monolithic built form of the structure serve to give it a horizontal emphasis. 8. The appeal scheme is presented as a contemporary two-storey extension seeking to reflect the existing building’s industrial aesthetic, whilst using contrasting materials to ensure that the proposal reads as a secondary addition.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision However, the proposal fails to pick on the building’s design features, having particular regard to the pattern of fenestration, proportions, banding and chamfered details which give the structure its distinctive rhythm and strong horizontal emphasis. This would result in a disjointed built form, which would bear little visual relationship with the host building and stand out as an alien 9. The incongruous nature of the proposal would also be exacerbated by the excessive bulk and massing of the extension. The extension would only be modestly set back on the west elevation, and thus fail to appear as a subservient addition. Moreover, the addition of a metal balustrade would only serve to further emphasise the inappropriate scale and design approach of the proposal, which would give the building an awkward, top-heavy appearance. Given the magnitude of the harm, the imposition of a condition requiring the submission of material details would not overcome my concerns. 10. For the reasons detailed above, the appeal scheme would cause unacceptable harm to the external appearance of the building, with particular regard to its principal elevation.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Whilst I accept that the existing office block may appear dated and in need of rejuvenation, any alterations would need to be undertaken in a manner which does not have a detrimental effect on the external appearance of the host building. Living conditions 11. As part of the prior approval process, the Local Planning Authority is required to consider whether the proposal would provide adequate natural light in all habitable rooms of the new dwellinghouses (AA.2.(1)(f)). Habitable rooms are defined in the GPDO as ‘any rooms used or intended to be used for sleeping or living which are not solely used for cooking purposes, but does not include bath https://www.gov.uk/planning-inspectorate 2

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Whilst I accept that the existing office block may appear dated and in need of rejuvenation, any alterations would need to be undertaken in a manner which does not have a detrimental effect on the external appearance of the host building. Living conditions 11. As part of the prior approval process, the Local Planning Authority is required to consider whether the proposal would provide adequate natural light in all habitable rooms of the new dwellinghouses (AA.2.(1)(f)). Habitable rooms are defined in the GPDO as ‘any rooms used or intended to be used for sleeping or living which are not solely used for cooking purposes, but does not include bath https://www.gov.uk/planning-inspectorate 2

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Appeal Decision APP/F5540/W/22/3296413 or toilet facilities, service rooms, corridors, laundry rooms, hallways or utility rooms’. 12. The Daylight and Sunlight Report submitted as part of the appeal includes an assessment of interior daylighting, using an Average Daylight Factor test. As the previous British Standard BS 8206-2:2008 (Lighting for Buildings) was replaced in June 2019 by BS EN 17037:2018 (Daylight in Buildings), the Average Daylight Factor for new accommodation has been deleted and replaced. I have nevertheless had regard to the Daylight and Sunlight Report, as this is the only technical analysis available. 13. The Council accepts that all proposed habitable rooms would receive an appropriate level of daylight, but has raised concerns regarding the level of sunlight for some of the habitable rooms, which would be below the recommended standards. I am mindful that the Framework advocates 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. 14.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision In this particular case, the proposed dwellings would receive sunlight for at least part of the day. There are some deficiencies arising from the calculations undertaken, but in most instances, this affects rooms which are not served by a single window. Moreover, the proposed windows would generally be sited at reasonable distance away from neighbouring buildings and, having regard to the presented evidence, I am overall satisfied that the appeal scheme would provide adequate natural light for the habitable rooms of the proposed dwellings. Locally Significant Industrial Area 15. The appeal site lies within the Power Road Industrial Estate, which is designated as a Locally Significant Industrial Site (LSIS). These are defined as employment area of Borough wide significance providing industrial and warehousing capacity which, as required by Policy ED2 of the Local Plan 2015- 2030, should be protected. Paragraph AA.2(i) of Schedule 2, Part 20, Class AA of the GPDO requires the Local Planning Authority to assess the impacts of the introduction of, or an increase in, a residential use of premises in the area on the carrying on of any trade, business or other use of land in the area. 16.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision The appellant’s submissions are supported by a map of the commercial premises located within proximity to the appeal site, which include varying types of uses, including car showrooms, garage services, offices and studios. This is consistent with my own observations. Whilst the appeal site lies within an industrial estate, the Council has presented no detailed evidence suggesting that these neighbouring uses operate or need to operate on a twenty-four-hour basis and would give rise to a level of noise, which would be incompatible with the introduction of residential development on the site. I am also mindful that the site lies within an urban area and next to a busy thoroughfare, where some degree of noise would have to be expected by future occupiers of the development. 17. Although the appeal premises are currently vacant, I also note that the proposal seeks to retain the existing office use. Overall, and in the absence of substantive evidence to the contrary, I have no reasons to believe that the proposed residential use would compromise the objectives of Power Road https://www.gov.uk/planning-inspectorate 3

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — Appeal Decision Appeal Decision APP/F5540/W/22/3296413 Industrial Estate as a LSIS, or the carrying on of any trade, business or other use of land in the area. Conclusion 18. For the reasons detailed above, I conclude that prior approval should not be granted, and the appeal should be dismissed.

250 Gunnersbury Avenue, LONDON, W4 5QB — London Borough of Hounslow — S Edwards INSPECTOR https://www.gov.uk/planning-inspectorate 4