26 Renters Avenue , London, Barnet, NW4 3RB

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Site visit made on 19 June 2025 by M Cryan BA(Hons) DipTP MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 25 September 2025 Appeal Ref: APP/N5090/W/25/3362951 26 Renters Avenue, Hendon, London NW4 3RB • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by BY Developments against the decision of the Council of the London Borough of Barnet. • The application reference is 24/5537/FUL. • The development proposed is the conversion of the property to four self-contained flats, including: additional rear extension to the rear of the garage; additional ground floor rear extension to the rear of the main property; change of material for the infill extension between the main house and the garage; additional depth on the first-floor rear extension; provision of an outbuilding as an ancillary gym for residents. Decision 1. The appeal is dismissed. Applications for costs 2. An application for costs was made by BY Developments against the Council of the London Borough of Barnet. This application is the subject of a separate Decision. Preliminary Matters 3.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision I have been appointed to determine three appeals on the same site. Two of the proposed developments are very similar; the main issue is the same in both appeals, and they are the subject of separate Decisions (within a single decision letter) (PINS Refs: APP/N5090/W/24/3357517 and APP/N5090/W/25/3362951). This decision relates to a markedly different proposal which raises different main issues, and I have therefore dealt with it here on its own. 4. The new Barnet Local Plan (“the BLP”) was adopted on 4 March 2025. It replaced the 2012 version of that plan, the policies of which had been referred to in the decision notice issued by the Council. The appeal submissions were made in the light of the new local plan and its policies; I have determined the appeal with reference to the up-to-date development plan. 5. As well as the other two appeals mentioned above, the appeal site has a considerable recent planning history. Of particular relevance here are three extant planning permissions, which were referred to in the appellant’s submissions: • Planning permission reference 22/2472/FUL, granted on 2 March 2023 (“the March 2023 permission”), for a development described as “conversion of the existing dwelling into 4no.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision self-contained flats including, Part single, part two storey side and rear extension and conversion of the existing garage. Roof alterations including side and rear dormers and raising of the eaves. https://www.gov.uk/planning-inspectorate

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision self-contained flats including, Part single, part two storey side and rear extension and conversion of the existing garage. Roof alterations including side and rear dormers and raising of the eaves. https://www.gov.uk/planning-inspectorate

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/25/3362951 Associated refuse/recycling, amenity space, cycle storage and off-street parking”; • Planning permission reference 23/1496/FUL, granted on 6 November 2023 (“the November 2023 permission”), for a development described as “conversion of the existing dwelling into 4no. self-contained flats including, part single, part two storey side and rear extension and conversion of the existing garage. Roof alterations including side and rear dormers, front rooflights and raising of the eaves. Erection of a rear outbuilding and front porch. Associated refuse/recycling, amenity space, cycle storage and off-street parking”; and • Planning permission reference 24/1317/FUL, granted on 23 May 2024 (“the 2024 permission”), for a development described as “demolition of the existing dwelling and erection of 2no. two semi detached dwellings with rooms in the roofspace and basement level with associated lightwells. Associated amenity space, refuse and recycling storage and cycle parking and outbuilding”. I address them at relevant points in my reasons below. Main Issues 6.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision The main issues are: • The effect of the proposed development on the character and appearance of the area; and • Whether the development would provide acceptable living conditions for future occupiers, with particular regard to the amount and quality of living space, daylight and sunlight, natural ventilation, and outlook. Reasons Character and appearance 7. The appeal property is a two-storey detached dwelling house on a corner plot, on an inside bend of Renters Avenue at its junction with Cheyne Walk. The appeal property has a two-storey flat-roofed side extension, incorporating a built-in garage, as well as a separate detached garage angled alongside. There is a shallow front forecourt, largely given over to a driveway but with some soft landscaping, and a larger rear garden with a side boundary fence to the street. 8. The surrounding area is predominantly residential, with detached, semi-detached and terraced housing. Many properties in the neighbourhood have been extended or otherwise altered, including by being converted from houses to flats, though extensions are generally subservient to the host building in line with advice in the Council’s 2016 Residential Design Guidance Supplementary Planning Document.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Side-to-side separation distances between dwellings are often short, giving stretches of some streets in the area a relatively dense and closely-built feel; where the rear gardens of properties on corner plots have side boundaries onto neighbouring streets, as is the case with the appeal property, the gaps which result allow glimpses of rear elevations and trees in rear gardens which give those sections of the streets a pleasant openness which makes a positive contribution to the character and appearance of the area. https://www.gov.uk/planning-inspectorate 2

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Side-to-side separation distances between dwellings are often short, giving stretches of some streets in the area a relatively dense and closely-built feel; where the rear gardens of properties on corner plots have side boundaries onto neighbouring streets, as is the case with the appeal property, the gaps which result allow glimpses of rear elevations and trees in rear gardens which give those sections of the streets a pleasant openness which makes a positive contribution to the character and appearance of the area. https://www.gov.uk/planning-inspectorate 2

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/25/3362951 9. The proposed development is the extension of the appeal property and its conversion from a single dwellinghouse to four self-contained flats. A very substantial ground floor extension would wrap around the rear and side of the building; above much of which would be a large side and rear first-floor extension. The building would be topped with a large crown roof, with living accommodation throughout the entire loft level. Altogether, the proposal would represent a significant increase in the size of the building on the appeal site. 10. The appellant suggests that the shape of the plot – which widens towards the rear because of the angle of the bend in Renters Avenue – and its corner position mean that the additional built massing could be accommodated without disrupting the overall character of the area. However, the limited set down from the main crown roof to the secondary crown roof on the side and rear extension, and indeed the overall size of the extension, mean that it would not read as a subservient addition to the original building.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Instead, the building as a whole would take on a size and scale which would appear dominant and disproportionately large when compared to the prevailing character of the neighbourhood, and its corner position would give it a particular prominence locally. The extensions would also infill a considerable part of the gap between the appeal property and No 28, closing off much of the view of rear elevations and garden trees which currently enhance the sense of spaciousness and greenness in the area. 11. The appellant has argued that the presence of the existing detached garage means there is already substantial massing at both the ground and first-floor levels on the site. However, the scale of what is proposed here goes way beyond the massing of a garage – even one with a pitched roof – so this is not a persuasive argument in favour of the appeal scheme. The developments permitted by the March 2023 and November 2023 permissions include substantial ground floor side extensions, the form and massing of which (if not the precise detailing) would be broadly similar to the ground floor element of this proposal.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision However, the size and bulk of the first-floor and roof extensions proposed would far exceed that permitted by those two permissions – I do not therefore agree with the appellant’s suggestion that the proposal is simply a logical “refinement” of the extant November 2023 permission. 12. The proposed development would also project further to the [east] side at first-floor level than the new-build allowed by the 2024 permission. This appeal scheme would be greater in terms of size and massing than any of these three extant permissions. Rather than being “wholly consistent with the form[s] of development already permitted”, the additional scale and bulk introduced by the appeal proposal would have a correspondingly greater impact on the character and appearance of the surrounding area, so the earlier permissions do not weigh significantly in its favour in this respect. 13.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision The appellant has also drawn my attention to numerous other extensions which have been granted planning permission1, most of which I was able to view during 1 At: • 17 Queens Gardens LPA Ref: 15-02048-HSE • 18 Queens Gardens LPA Ref: H-02395-10 • 20 Queens Gardens LPA Ref: 21-4051-HSE • 33 Shirehall Park LPA Ref: 17-2438-HSE • 56 Shirehall Park LPA Ref: 18-2753-HSE • 58 Shirehall Park LPA Ref: 17-3406-HSE • 60 Shirehall Park LPA Ref: H-05999-13 https://www.gov.uk/planning-inspectorate 3

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision The appellant has also drawn my attention to numerous other extensions which have been granted planning permission1, most of which I was able to view during 1 At: • 17 Queens Gardens LPA Ref: 15-02048-HSE • 18 Queens Gardens LPA Ref: H-02395-10 • 20 Queens Gardens LPA Ref: 21-4051-HSE • 33 Shirehall Park LPA Ref: 17-2438-HSE • 56 Shirehall Park LPA Ref: 18-2753-HSE • 58 Shirehall Park LPA Ref: 17-3406-HSE • 60 Shirehall Park LPA Ref: H-05999-13 https://www.gov.uk/planning-inspectorate 3

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/25/3362951 my site visit. It is evident that some large-scale side and rear extensions and roof enlargements have been allowed in the area; regardless of when planning permission was granted, they are therefore a part of the character and appearance of the area, though this would not in itself be a justification for allowing a significantly harmful scheme which does not comply with current development plan policies. 14. However, in most of these cases (including 89 Cheyne Walk, closest to the appeal site) the extension is in a position away from the street where its bulk and massing is, at least to some extent, shielded from the streetscene either by the host building or by one of its neighbours. In those examples on corner plots (at 22 Denehurst Gardens, 23 Beaufort Gardens, and 62 Basing Hill) the large extensions are close to, and can be seen from, the street at the side; however, in none of those cases has the extension filled in the side garden gap – and therefore closed down the openness of the area – anything like as much as would arise with the appeal scheme. None of these other examples therefore lend significant weight in support of the proposal before me. 15.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision I conclude that, because of its size, massing and siting, the proposed development would cause significant harm to the character and appearance of the area. It would therefore conflict with Policies CDH01 and CDH05 of the 2025 BLP, and Policy D3 of the London Plan 2021. While these policies are supportive of development which optimises the capacity of sites, among other things they also seek to ensure that new development is of high-quality design which respond sensitively to the form, scale, and massing of the local area, and that extensions complement, and are subordinate in size and scale to, the existing building. Living conditions Living space 16. Policy D6 of the London Plan 2021 seeks to ensure that housing development is of a high design quality ad provides comfortable and functional accommodation, including in respect of internal living space; among other things, it requires that the minimum floor to ceiling height must be 2.5m for at least 75% of the Gross Internal Area of each dwelling. 17.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision In response to concerns about Unit 4 (within the loft level) raised by the Council while the application was being determined, revised plans were submitted with an annotation showing that 76% of Unit 4 would comply with the standard. However, that figure appears to include an area of the stairwell outside the private front door of Unit 4 which, while it would only normally serve that flat, is communal space rather than part of the dwelling. Excluding that space would, by the Council’s calculation, take the compliant area within Unit 4 below the 75% threshold. 18. The appellant has not provided their own figure excluding that area, and suggests that the argument that the staircase outside the front door should be excluded is • 1 Cheyne Walk LPA Ref: 15-02287-HSE • 22 Denehurst Gardens LPA Ref: 16/00041/HSE • 23 Beaufort Gardens LPA Ref: W05716A/00 • 6 Beaufort Gardens LPA Ref: 14/07389/HSE • 8 Beaufort Gardens LPA Ref: 18/4225/HSE • 89 Cheyne Walk LPA Ref: W08039 • 32 Cheyne Walk LPA Ref: 23/3029/HSE • 62 Basing Hill LPA Ref: C15182A/03 https://www.gov.uk/planning-inspectorate 4

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/25/3362951 not supported by the London Housing Design Standards2 (“the HDS”) or by standard practice. However, I can find nothing in either the HDS or the Council’s own 2016 Sustainable Design and Construction Supplementary Planning Document (“the SDC SPD”) which supports the appellant’s approach; in my view an area outside the private front door of a dwelling cannot sensibly be described as also being within that dwelling. Daylight, sunlight, ventilation and outlook 19. The kitchen within Unit 4 would have a window in a dormer on the western elevation, and a rooflight on the northern elevation; the dormer window would have obscure glazing. The SDC SPD advises that the area of glazing to habitable rooms should not normally be less than 20% of the internal floor area of the room, while the HDS advises that “all habitable rooms (including a kitchen/dining room) should receive natural light and have at least one openable window that provides a view out when seated”. 20.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision The main parties disagree about the area of the windows in the kitchen; based on the revised plans, the Council calculates it would not meet the 20% standard and would not therefore ensure adequate daylight, while the appellant calculates it to be 26% of the room’s floor area. While the appellant argues that the kitchen would be “dual aspect” and would provide “an acceptable level of outlook”, in my view an obscure glazed window and relatively high rooflight would be likely to provide only a limited outlook. However, and notwithstanding the Council’s on this matter related to the ceiling heights issue, together (particularly in combination with other windows in other rooms of what would be a multi-aspect unit) they would be likely to provide satisfactory natural ventilation. 21. I also need to consider whether the kitchen should be treated as a “habitable room” – the Council suggests that, based on its 10.3m2 size, it should be.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision The SDC SPD defines a habitable room as one “the primary purpose of which is for living, sleeping or dining, including kitchens where the total area is more than 13m2 (including fittings)”; the HDS does not provide a space-based definition of a habitable room, but its advice (quoted in paragraph 19 above) appears, on my reading, to apply to combined kitchen/dining rooms, rather than to kitchens and dining rooms. 22. I agree that the size and shape of the kitchen is such that it could well be used as (say) an informal dining area – there certainly appears to be adequate space for a small table and two chairs, which would be likely to meet the day-to-day needs of the occupiers of a one-bedroom, two-person flat. However, there would also be a separate generously sized (if slightly awkwardly shaped) combined living and dining room available for that purpose, so occupiers would not be dependent on the kitchen serving as a habitable room. Findings on this main issue 23.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Taking these points together, and of course taking the submitted drawings at their face value insofar as they identify the purpose and layout of the various rooms within the development, I am satisfied that there would be no harmful shortcomings in relation to daylight, sunlight, ventilation or outlook. 2 Mayor of London; London Plan Guidance: Housing Design Standards, June 2023 https://www.gov.uk/planning-inspectorate 5

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Taking these points together, and of course taking the submitted drawings at their face value insofar as they identify the purpose and layout of the various rooms within the development, I am satisfied that there would be no harmful shortcomings in relation to daylight, sunlight, ventilation or outlook. 2 Mayor of London; London Plan Guidance: Housing Design Standards, June 2023 https://www.gov.uk/planning-inspectorate 5

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision Appeal Decision APP/N5090/W/25/3362951 24. However, while the shortfall in respect of ceiling heights may be small, the standard in the development plan sets a minimum requirement, not a maximum target. While the SDC SPD indicates that lower space standards may be permitted where development is of an exemplary design, given my findings on the first main issue that is not an exception which would apply here. 25. I therefore conclude that, because of its shortcomings in respect of ceiling heights within Unit 4, the proposed development would not provide acceptable living conditions for future occupiers. As a result, there would be conflict with Policy CDH01 of the 2025 BLP, and with Policies D3 and D6 of the London Plan 2021. As well as setting out the living space standard referred to above, these policies seek to ensure that development provides comfortable and functional layouts which are fit for purpose, and which offer a good standard of amenity for occupiers. Other Matters 26. The appeal scheme would see four new dwellings created, a net increase of three over the current position.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — Appeal Decision This would provide a modest boost to the supply of housing in the area; this would be a benefit of the development, although it would come at the cost of significant harm to the character and appearance of the area. The two extant 2023 planning permissions would also provide a similar uplift in housing supply, and they (along with the 2024 permission for two dwellings) are clear fallback positions for the appellant. For the reasons I have set out, the appeal proposal would be more harmful than the consented schemes. Consequently, I find that the fallback positions do not carry significant weight in favour of the appeal scheme. Conclusion 27. For the reasons given above, and taking into account all other relevant matters raised, I conclude that both appeals should be dismissed.

26 Renters Avenue , London, Barnet, NW4 3RB — London Borough of Barnet — M Cryan Inspector https://www.gov.uk/planning-inspectorate 6