Single storey ground side floor extension and proposed loft conversion with rear facing dormer

Appeal Decision Site visit made on 28 February 2023 by Helen O'Connor LLB MA MRTPI an Inspector appointed by the Secretary of State Decision date: 2 March 2023 Appeal Ref: APP/V5570/D/22/3308661 37 Aberdeen Park, Islington, London N5 2AR • The appeal is made under section 78 of the Town and Country Planning Act 1990 against a refusal to grant planning permission. • The appeal is made by Ms Hofer against the decision of the Council of the London Borough of Islington. • The application Ref P2022/1815/FUL, dated 10 May 2022, was refused by notice dated 4 August 2022. • The development proposed is a single storey ground side floor extension and proposed loft conversion with rear facing dormer. Decision 1. The appeal is dismissed insofar as it relates to the single storey ground side floor extension. The appeal is allowed only insofar as it relates to the proposed loft conversion with rear facing dormer at 37 Aberdeen Park, Islington, London N5 2AR in accordance with the terms of the application, Ref P2022/1815/FUL, dated 10 May 2022, so far as relevant to that part of the development hereby permitted and subject to the following conditions. For the avoidance of doubt, the alterations to the ground floor fenestration in the proposed rear elevation do not form part of the allowed loft conversion with rear facing dormer. 1) The development hereby permitted shall begin not later than 3 years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans including the external surface materials denoted in them: Site plan, drawing number 255-2PM-XX-XX-DR-A- 00101; Proposed front and side 1 elevation, drawing number 255-2PM- XX-XX-DR-A-10401; Proposed rear and side 2 elevation, drawing number 255-2PM-XX-XX-DR-A-10402; Proposed first floor plan, drawing number 255-2PM-XX-01-DR-A-10201; Proposed second floor plan, drawing number 255-2PM-A-10201; Proposed roof plan, drawing number 255- 2PM-XX-RF-DR-A-10201; Proposed sections AA and BB, drawing number 255-2PM-XX-XX-DR-A-10301; Proposed sections CC and DD, drawing number 255-2PM-XX-XX-DR-A-10302. Main Issue 2. The main issue is whether the proposed single storey ground side floor extension preserves or enhances the character or appearance of the Aberdeen Park Conservation Area (CA). Appeal Decision APP/V5570/D/22/3308661 2 Reasons 3. The CA covers a contained mostly residential estate grouped around the roughly circular route of Aberdeen Park. Its significance is primarily derived from the large, detached Victorian villas set within generous plots that reflect an Italianate style of architecture. The ordered layout facing onto the curving alignment of the road, quality of the detailing, and established planting and trees combine to convey a quiet, spacious and verdant residential estate. In addition, there is a notable presence of attractively balanced, early 20th century semi-detached housing within the CA, thereby reflecting its evolution over time. Although their form and scale defer to the larger villas, they possess pleasant qualities in their own right and their regular set back generally maintains a similar relationship with the street. As such, their configuration and gardens reinforce some of the defining characteristics of the CA. Hence, they also contribute towards its significance. 4. This is recognised in the Aberdeen Park (CA27) Conservation Area Design Guidelines, January 2002 (the Guidelines) which state that the spacious character of the area owes much to the gaps between the detached and semi- detached houses, with views through to trees and rear gardens1. I am mindful of my statutory duty2 to pay special attention to the desirability of preserving or enhancing the character or appearance of the CA. 5. 37 Aberdeen Park is one such semi-detached early 20th century dwelling. As part of a pair with no.35, it has a broadly symmetrical form and appearance. The angled orientation of the pair responds to a curve in the road, and the distinctive projecting hipped roof element emphasises their central placement addressing it. The sense of balance is enhanced by the pair being flanked by similar semi-detached pairs. The deliberate spacing, planted front gardens and regular set back of the group of dwellings numbered 31-41 attractively ‘turn the corner’. As such, no.37 makes a positive contribution to the pleasant, spacious character and appearance of the CA, with its central corner position giving the appeal site added prominence. 6. The proposals comprise several components, including one which would introduce a single storey broadly wedge-shaped ground floor side extension to no.37. The structure would encroach into the garden space between the appeal property and no.39. As such, its presence would erode the spacious gap and displace some of the garden greenery. In addition, by extending built form to the side of no.37, it would disrupt the impression of balance with no.35. 7. The adverse impact would be exacerbated by further factors. Firstly, the tapering footprint and cranked position of the side extension relative to the main dwelling would result in an awkward form. The angled roof would add disproportionate complexity to the appearance of the dwelling, which would be at odds with the otherwise deliberately balanced roof shape. 8. Secondly, the external surface of the walls would comprise green ceramic cladding. Few specific details of the intended finish have been given, but the colour and likely texture would visually contrast with the otherwise muted unpainted pebble dash principal elevations of the host and nearby dwellings. Therefore, it is likely that such a finish would draw the eye, which would be 1 Paragraph 27.12 2 Section 72 Planning (Listed Buildings and Conservation Areas) Act 1990 Appeal Decision APP/V5570/D/22/3308661 3 inappropriate for a subordinate addition. This would conflict with the advice contained in the Council’s Urban Design Guide, Supplementary Planning Document, January 2017. It advises3 that care needs to be taken to ensure that new material in developments is sympathetic with the local vernacular. Any new building should have a harmonious visual relationship with its neighbours and consistency and continuity are important. The proposed palette of materials should not jar, inappropriately draw the eye, or otherwise undermine the local character or distinctiveness of the area. 9. The appellant contends that green ceramic cladding would be visually similar in scale and height but of a much higher quality than the ivy-covered timber fence and gate which it would replace. However, based on what is before me I am not persuaded that such cladding would be a convincing substitute for the organic greenery and texture of vegetation. It follows that it would not result in a similar subtle, softening effect, but rather would look incongruous. 10. Thirdly, the proposed glazed doors in the front part of the proposed side extension would bear little relationship in terms of proportion and placement to the distinctive pattern of fenestration in the principal elevations of nos.35-37. It is likely that the sizeable area of glazing would be visible from the street, especially when the kitchen was lit internally. Whilst a green ceramic clad sliding shutter is denoted, there is no guarantee as to when it would be used. 11. Finally, given the prominent corner position of the appeal property, these effects would be visible in the street scene. Although it is likely that there would be some screening derived from the combination of the grass verge, low boundary wall and garden hedging, the upper portion of the side extension would appear above them. Moreover, the height of garden hedges cannot be guaranteed. Accordingly, whilst screening would limit the extent of the harm I have identified, it would not fully address, or outweigh it. 12. Overall, there is little before me to show how the proposed side extension would sympathetically or positively respond to the building character of the host dwelling as part of a balanced pair. Rather I find that the factors highlighted would combine to have a harmful impact on the character and appearance of the CA. It follows that I cannot agree with the appellant’s assertion that the impact would be a neutral one. 13. Furthermore, the Guidelines4 go into some detail as to what might be appropriate for individual properties within the CA. They state that side extensions will not be permitted save for specified exceptions, due to the harmful effect that they would have on the gaps between properties. A similar stance is made in relation to new side garages and carports. The appeal property is not listed as an exception to the general approach to side extensions. Those properties that are, would have such development supported where a rebuilt single storey side extension would improve design. Logic would dictate that in those limited cases, there is already a side extension or structure in place to be rebuilt. The Guidelines do not have the status of a mandatory policy. Nevertheless, they are bespoke to this CA. Therefore, the conflict identified attracts considerable weight. 3 Paragraph 5.112 4 Paragraphs 27.11 & 27.19 Appeal Decision APP/V5570/D/22/3308661 4 14. Examples of other side extensions in the CA are drawn to my attention, the closest of which is at no.31 and therefore, has most relevance. The details before me do not indicate when the extension in that case was permitted. However, unlike the appeal property, no.31 is one of the exceptions listed in the Guidelines to the normal approach to side extensions, which would suggest its presence is longstanding. 15. Reference is made to a white garage at no.25. However, my observations were that there is no such property nearby and the photograph provided reflects the garage at no.47. Examples at 47 and 49 Aberdeen Park are further away and would not be read with the appeal site as part of the group that ‘turn the corner’ identified above. Moreover, the garage at no.47 reinforces my concerns and the general approach in the Guidelines. As such, it would not provide strong justification for development that would further erode the gaps between dwellings. I have also had regard to the planning permissions granted at no.495. However, the extensions permitted in that case differ markedly from the appeal proposal in terms of set-back, form, materials and fenestration. Consequently, I am not persuaded that any of the examples highlighted are directly comparable to the appeal proposal and so they carry limited weight in its favour. 16. Notwithstanding that the proposal is of a modest domestic scale, this would not amount to a persuasive reason to permit otherwise harmful development, as it could be repeated too often. Ultimately this could cause significant cumulative detriment to the significance of the CA by gradual erosion. 17. Hence, the proposal would be harmful to the significance of the CA, a designated heritage asset. However, cognisant of its modest scale, it would result in less than substantial harm. Paragraph 202 of the National Planning Policy Framework (the Framework) states that in these circumstances, this harm should be weighed against the public benefits of the proposal. 18. The proposal would improve the standard of accommodation for the appellant and future occupiers of the appeal property. Whilst this is primarily a private benefit, some public benefit would be generally derived from upgrading existing housing stock. However, reflective of its modest nature, the degree of benefit in this case would be small, and so it carries limited positive weight. I have also had regard to the representations in support of the scheme, but they raise no additional substantive matters. 19. Paragraph 199 of the Framework stipulates that great weight should be given to the conservation of designated heritage assets. This is underlined by the emphasis given in the wording of the statutory duty. Therefore, the limited weight given to the public benefits in this case does not outweigh the great weight attributed to the harm caused to the significance of the CA. Consequently, the proposal would conflict with the national historic environment policy. 20. In addition to the harmful single storey side extension, the proposal would introduce glazed sliding doors in the rear elevation and a loft conversion with dormer window, balcony and rooflights. The refusal reason on the Council’s decision notice refers only to the single storey side extension and it is reasonably clear from the Council’s officer report that it found the other 5 Planning references P110825 and P2017/3594/FUL Appeal Decision APP/V5570/D/22/3308661 5 elements broadly acceptable. The dormer window and glazed sliding doors would be located at the rear, and therefore concern the least prominent elevation of the dwelling. As such, this part of the dwelling would be less sensitive and possesses greater capacity to accommodate alterations without resulting in harm to the CA. My observations of the area and consideration of the Guidelines would not lead me to find other than the Council with respect to these elements of the proposal. Nevertheless, they would not justify the harm I have identified in relation to the single storey side extension. 21. Accordingly, I find that the single storey ground side floor extension would fail to preserve or enhance the character or appearance of the CA. It follows that it would conflict with policies D1, D4 and HC1 of the London Plan, March 2021, policies CS8 and CS9 of Islington’s Core Strategy, February 2011 and policies DM2.1 and DM2.3 of Islington’s Local Plan: Development Management Policies, June 2013. In combination, and amongst other matters, these policies seek high quality design that protects or enhances the significance of the historic environment. Conclusion 22. I have found in relation to the main issue concerning the single storey ground side floor extension, that unjustified harm would result to the significance of the CA. Therefore, this element of the proposal should not succeed. Under section 79(1)(b) of the Town and Country Planning Act 1990 I have discretion to split the decision by allowing one part of a scheme and dismissing the rest. However, this would only be possible where respective components of a proposal are clearly severable from the remainder of the proposals in physical and functional terms. 23. Having regard to the submitted plans, I am satisfied that the loft conversion involving dormer window, balcony and rooflights would be severable. However, this would not be true of the proposed changes to fenestration in the ground floor rear elevation, as these would be associated with the extended ground floor layout with the proposed side extension and would, in part, connect with it. Accordingly, it would be appropriate to use the power to split the decision in these circumstances to allow the loft conversion but to dismiss the remainder of the proposal. 24. In relation to the loft conversion, I have considered the conditions suggested by the Council on the appeal questionnaire. I have imposed conditions to reflect the three year period in which the development may be implemented and have specified the relevant approved plans such that the loft conversion shall be undertaken in accordance with these, as this provides certainty. The proposed plans are sufficiently annotated indicating the materials to be used in the loft conversion, so this matter would be adequately covered by the same condition. 25. Therefore, for the reasons given above I conclude that the appeal should be allowed in part and dismissed in part. Helen O’Connor Inspector