Two storey side extension with basement space and conversion of roof space to habitable use to include 2 rear dormers and 2 side rooflights, involving demolition of existing garage and car port

Appeal Decision Site visit made on 11 March 2019 by M Russell BA (Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 04 April 2019 Appeal Ref: APP/R5510/D/18/3219378 5 Court Road, Ickenham UB10 8TE • 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 Mr & Mrs S Marwaha against the decision of the Council of the London Borough of Hillingdon. • The application Ref 68638/APP/2018/2785, dated 30 July 2018, was refused by notice dated 9 October 2018. • The development proposed is two storey side extension with basement space and conversion of roof space to habitable use to include 2 rear dormers and 2 side rooflights, involving demolition of existing garage and car port. Decision 1. The appeal is dismissed. Procedural Matter 2. I note the Council’s delegated report identifies some discrepancies on the submitted drawings. The anomalies between the floor plans and elevations in terms of a proposed rear bay window not being shown on the side elevation and measurements between floor plans and elevations not corresponding are relatively minor and have not hindered my understanding of the proposals for the purposes of my assessment. As I am dismissing the appeal on the substantive grounds indicated by the Council, I do not consider that these anomalies require rectifying at this late stage. Main Issues 3. The main issue is whether the proposal would preserve or enhance the character or appearance of the Ickenham Conservation Area (CA). Reasons 4. No 5 Court Road is a distinctive two-storey detached dwelling, with a strong Arts and Crafts movement influence situated within a spacious plot. The dwelling is set in from the side boundaries with substantial soft landscaped front and rear gardens. The appeal site is situated within the Ickenham Conservation Area, the significance of which derives from its mixture of dwelling styles, often traditional in form, well-spaced and set back from the road with mature soft landscaping within curtilages. No 5 reflects these characteristics and makes a positive contribution to the character and appearance of the CA. Appeal Decision APP/r5510/D/18/3219378 2 5. The shape of the existing dwelling with its steeply sloped catslide roof form to either side gives it a balanced appearance, whilst also providing a sense of space between the main bulk of the dwelling and its side boundaries. The design of the proposed two-storey side extension would remove the catslide roof form to that side of the dwelling. The hipped roof with eaves height at first floor level, the expanse of brickwork to the front elevation and integral double garage door would combine to emphasise the width and bulk of the proposal relative to the original dwelling. To the rear elevation, the proposed bay window would have wider proportions than those existing on the dwelling. For these reasons, the extension would compete with the overall balance of the house and would remove the spaciousness that currently exists between the side boundary with No 5A Court Road. As a result, the proposal would neither complement the distinctive style of the host dwelling nor preserve or enhance the character or appearance of the CA. 6. There is an existing car port which sits close to a dense conifer hedge boundary with No 5A court Road. The trees provide a soft buffer between the host dwelling and No 5A and this positively contributes to the mature soft landscaping that forms part of the special character of the CA. The proposal, which includes a basement level, would necessitate a significant amount of excavation close to this boundary. The appellants have not submitted a tree survey or arboricultural impact assessment to demonstrate that the proposed development could be carried out without impacting on the root protection zone of these conifers. I acknowledge the appellants do not intend to harm or remove these trees and that the proposed basement would utilise contiguous piles to retain the soils around their roots. However, I have no substantive evidence before me to demonstrate the proposed methods would be effective. I consider precise details of the methods to be employed would need to be submitted prior to the granting of planning permission to give certainty that the trees would be retained. The appellant has therefore failed to demonstrate that the proposal would not result in harm to the trees, the loss of which would have a harmful impact on the character and appearance of the CA. 7. Taking all matters into account, the proposal would result in less than substantial harm accounting for the scale of the development proposed and extent of tree planting that could be lost relative to the wider character and appearance of the CA. In accordance with Paragraph 196 of the Framework less than substantial harm should be weighed against the public benefits of the proposal. In this case some limited public benefit would arise through the provision of a larger dwelling. However, I must attach great weight to the need to conserve the CA and find therefore that the limited public benefits do not outweigh the less than substantial harm identified. 8. Overall, I find the proposal fails to preserve or enhance the character or appearance of the CA. This would conflict with Policies BE1 and HE1 of the Hillingdon Local Plan: Part One – Strategic Policies (2012) and Policies BE4, BE13, BE15, BE19 and BE38 of the London Borough of Hillingdon Unitary Development Plan (saved policies 2007) which require amongst other things that development enhances local distinctiveness, preserves and enhances Hillingdon’s Conservation Areas, harmonises with the existing streetscene and the scale, form, architectural composition and proportions of the original building and retains landscape features of merit, with applicants required to provide accurate tree surveys where proposals would affect any existing trees. The proposal would also conflict with Policy 7.8 of the London Plan (2016) Appeal Decision APP/r5510/D/18/3219378 3 which states that development affecting heritage assets and their settings should conserve their significance. In reaching this conclusion I have also given regard to the Hillingdon Design and Accessibility Statement Supplementary Planning Document – Residential Extensions (2008) which amongst other things seeks to ensure that extensions appear subordinate to the main dwelling. Such policies and guidance are consistent with the National Planning Policy Framework (2019) which requires great weight to be given to the conservation of designated heritage assets and that any harm to these should require clear and convincing justification. Other Matter 9. My attention has been drawn to previous proposals to extend the dwelling, two of which were refused planning permission and another granted. I have assessed the appeal proposal on its own merits and, for the reasons set out, consider this would not preserve or enhance the character or appearance of the CA. The scheme previously approved by the Council in 2012 takes a different design approach to the current appeal proposal and is therefore not comparable. Conclusion 10. For the reasons given above and taking into account all other matters raised, I conclude that the appeal should be dismissed. M Russell INSPECTOR