Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision Site visit made on 9 September 2024 by U P Han BSc (Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 19 September 2024 Appeal Ref: APP/R5510/W/24/3340636 Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX • 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 Mr Curtis Komla Lebne against the decision of the Council of the London Borough of Hillingdon. • The application Ref is 74383/APP/2023/2932. • The development proposed is rear ground floor extension and rear roof dormer extension. Decision 1. The appeal is dismissed. Preliminary Matters 2. The appeal site is within the Northwood, Frithwood Conservation Area (the CA) wherein I have a statutory duty under Section 72 (1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 to pay special attention to the desirability of preserving or enhancing the character or appearance of the area. In addition, the National Planning Policy Framework (the Framework) requires great weight to be given to the conservation of heritage assets. Main Issues 3.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision The main issues are the effect of the proposed development on the: • character and appearance of the host building and the CA; and • living conditions of the occupiers of 18A Frithwood Avenue (No 18A) with regard to outlook, light and privacy. Reasons Character and appearance 4. The significance of the CA, within which the appeal site is located, is derived from a combination of its architectural, historical, and cultural value which contribute to its overall charm and aesthetic. The area is primarily characterised by large individually designed detached houses, mature tree lined avenues and large landscaped gardens. https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision The main issues are the effect of the proposed development on the: • character and appearance of the host building and the CA; and • living conditions of the occupiers of 18A Frithwood Avenue (No 18A) with regard to outlook, light and privacy. Reasons Character and appearance 4. The significance of the CA, within which the appeal site is located, is derived from a combination of its architectural, historical, and cultural value which contribute to its overall charm and aesthetic. The area is primarily characterised by large individually designed detached houses, mature tree lined avenues and large landscaped gardens. https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision 5. The appeal site is one of such houses and comprises a two-storey self- contained flat, which forms part of a large two and a half storey detached house designed in the Arts and Crafts style. The site has a large front garden and parking area. The surrounding area is predominantly residential. 6. The proposal is for a rear single storey extension, a rear dormer roof extension and one front roof light to Flat 6 of 18 Frithwood Avenue (No 18). Flat 6 is located on the east side of the building and benefits from its own front door and rear private garden. While being a separate living unit, Flat 6 forms an integral part of No 18 and occupies an original ancillary wing. 7. The proposed rear single storey extension would span the full width of Flat 6, covering up a large proportion of its rear elevation and would sit just below the first floor windows. Due to its height and bulk, the extension would be a dominant and unsympathetic addition to the building. 8. The proposed rear dormer roof extension would cover the majority of the existing rear roof over Flat 6. While it would sit up from the eaves, the dormer would be at the same height as the ridge of the existing roof over Flat 6 and span the majority of its width.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision The additional mass at roof level would result in a bulky and top-heavy appearance to the property which would not reflect the proportions of the existing building or others in the area. While the proposed dormer is at the rear, there are clear views of the rear roof from Bayhurst Drive. The scale and position of the rear dormer would also mean that it would be partly visible from the front elevation. 9. The rear elevation of No 18 has modest hipped dormers which are positioned well within the rear roof slope and harmonise with the existing building. The large box dormer proposed would dominate and obscure the existing hipped roof to Flat 6, substantially altering its form. This would be incongruent with the characteristics of the existing roof including the modest hipped dormers. 10. The appellant suggests that the proposal would be consistent with the roof forms at 18A, 18B, 18C and 20 Frithwood Avenue and alterations and extensions to the host property which has resulted in a flat roof profile on the front elevation. However, there are clear material differences between the proposal and these examples.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision The roof form of No 18A has not been altered and the single storey rear extension has a hipped roof and is made of lightweight materials. Nos 18B and 18C have two-storey rear extensions with flat roofs which sit just above the eaves of the main roofs of the host buildings, so their roofs are not predominantly covered. No 20 has rear dormers but they sit comfortably within the roof, below the ridge, and are not visible from the front of the property. It is acknowledged that the front elevation has been compromised by the flat roof extension, but this example is also materially different to the proposal which includes a dormer roof extension. Furthermore, I am not aware of the full circumstances of these cases or the policies that applied at the time of their consideration. In any event, I have considered and determined the appeal proposal on its own individual merits. 11. The appellant suggests that the design and external appearance of the proposed development would be consistent with the roofscape of Bayhurst Drive.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision However, there is little substantive evidence before me to establish whether the proposal would be consistent with the roofscape of Bayhurst https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision However, there is little substantive evidence before me to establish whether the proposal would be consistent with the roofscape of Bayhurst https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision Drive. In any event, Bayhurst Drive is outside of the CA and does not set a design precedent. 12. While the dormer would only represent less than two thirds of the existing roof span of the whole rear elevation and would be located below the existing ridge and above the eaves of the main building, it would nevertheless, be at the same height as the ridge of the roof to the ancillary wing and cover the majority of its roof slope. The scale and mass of the proposed roof extension would have a dominant and incongruent effect on Flat 6 and the host building as a whole. 13. Although the proposed alterations to the front of the building are modest in scale, part of the rear dormer extension would be visible from the front of the property and would look harmfully out of place. 14. Consequently, the proposal would harm the character and appearance of the existing building and would fail to preserve or enhance the character and appearance of the CA. In terms of the Framework, the harm I have identified would be less than substantial. 15.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision Paragraph 208 of the Framework establishes that where a proposal would lead to less than substantial harm to the significance of a designated heritage asset (in this case the CA), this harm should be weighed against the public benefits of the proposal. 16. The appellant has not identified whether any potential harms to the CA would amount to substantial harm, total loss of less than substantial harm and has not explicitly identified any public benefits. The creation of extended residential accommodation would be largely a private benefit to occupiers of the flat, so I am only able to give this very limited weight. 17. Paragraph 205 of the Framework establishes that great weight should be given to the conservation of a designated heritage asset, and the very limited benefits I have found would not be sufficient to outweigh the harm identified. 18. For the above reasons, I conclude that the proposed development would harm the character and appearance of the host building and would thus fail to preserve or enhance the character and appearance of the CA.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision Hence, it would conflict with Policies BE1 and HE1 of the Hillingdon Local Plan: Part One - Strategic Policies (November 2012), Policies DMHB 4, DMHB 11, DMHB 12 and DMHD 1 of the Hillingdon Local Plan: Part Two - Development Management Policies (January 2020) and Policy D3 of the London Plan (2021). Together, these policies, amongst other matters, require development to conserve and/ or enhance heritage assets including conservation areas, achieve high quality design and ensure extensions are subordinate to the main dwelling. It would also not comply with the historic environment objectives of the Framework. Living Conditions 19. The appeal site shares a boundary with No 18A to the east. Flat 6, within the ancillary wing, is set back from the principal building line so that its front elevation is almost in line with the rear elevation of No 18A. No 18A has a https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision rear single storey conservatory which is set in from the boundary. The gap between the appeal site and No 18A is relatively narrow. 20. The changes in ground level mean that No 18A is set on a higher level than the appeal site. Consequently, the boundary treatment between the appeal site and No 18A is higher than usual with wooden fencing atop a low brick wall. Nevertheless, the height of the proposed extension closest to No 19A would be considerably higher than the existing boundary fence. Furthermore, given its expanse across the full width of the ancillary wing and its position in relation to No 18A which is set forward of Flat 6, the proposal would diminish the outlook from the rear facing opening of No 18A, creating an increased sense of enclosure. This would also result in overshadowing to the property and thereby loss of light to it. 21. The Council’s Decision Notice refers to the loss of privacy to No 18A. However, no substantive evidence has been put to me in this regard. The single storey rear extension would not include any windows on the side elevations.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — Appeal Decision Clear views of the ground floor windows of No 18A and the amenity space by the conservatory would be not easily obtained from the proposed rear facing dormers due to the appeal site being positioned further rearward than No 18A. Consequently, a relatively high level of privacy between the properties would be maintained. 22. I therefore conclude that while the proposed development would not unduly affect the privacy of No 18A, it would unacceptably harm the living conditions of the occupiers of No 18A with regard to outlook and light. This would conflict with Policies DMHB 11 and DMHD 1 of the Hillingdon Local Plan - Part Two - Development Management Policies (January 2020). Together, these policies, amongst other things, require development not to adversely impact the outlook, daylight and sunlight of neighbouring occupiers. Conclusion 23. The proposal conflicts with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. For the reasons given above the appeal should be dismissed.

Flat 6, 18 Frithwood Avenue, Northwood, HA6 3LX — London Borough of Hillingdon — U P Han INSPECTOR https://www.gov.uk/planning-inspectorate - Appeal Decision APP/R5510/W/24/3340636