Loft conversion involving creation of a rear dormer, 2no front and side roof lights

Appeal Decision Site visit made on 24 June 2019 by C McDonagh BA (Hons), MA Decision by Susan Ashworth BA (Hons) BPl MRTP an Inspector appointed by the Secretary of State Decision date: 9 July 2019 Appeal Ref: APP/L5810/D/19/3226275 20 Norman Avenue, Twickenham, TW1 2LY • 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 Mrs Lambert against the decision of the Council of the London Borough of Richmond upon Thames. • The application Ref 19/0544/HOT, dated 19 February 2019, was refused by notice dated 1 April 2019. • The development proposed is a loft conversion involving creation of a rear dormer, 2no front and side roof lights. Decision 1. The appeal is dismissed. Appeal Procedure 2. The site visit was undertaken by an Appeal Planning Officer whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal. Main Issues 3. The main issues in this appeal are the effect of the proposal on the character and appearance of the host property as a result of the raising of the roof ridge height and whether it would preserve or enhance the character or appearance of the Cambridge Park Conservation Area. Reasons for the Recommendation 4. The appeal site comprises a two-storey, semi-detached dwelling of red brick construction. The roof is hipped with a flat section to the rear and mirrors the attached neighbouring property. It is located on Norman Avenue within the Cambridge Park Conservation Area in a quiet residential area. The houses on Norman Avenue are locally designated as Buildings of Townscape Merit (BTM). As per the Buildings of Townscape Merit Supplementary Planning Document (BTMSPD), these houses are designated due to: their forming part of a distinctive and cohesive group of buildings; retaining their original architectural interest and integrity and are not subject to insensitive alterations; and have landmark quality or make a unique and positive contribution to the quality of the townscape. These buildings therefore add to the special characteristics of the conservation area and as per the Cambridge Park Conservation Area Appraisal (CPCAA) have remained largely unaltered, adding to its significance. Appeal Decision APP/L5810/D/19/3226275 2 5. The development proposed entails the installation of a rear dormer window, which will involve raising the roof ridge and a general reconfiguration of the roof. Rooflights are also proposed to the side and front elevation. The dormer will allow the loft of the property to provide additional living space, with an en- suite bedroom created. This would be facilitated by transforming the hipped and flat sections at the lower level into a single hipped area. 6. Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act) requires special attention to the desirability of preserving or enhancing the character or appearance of a conservation area. National policy on heritage assets, which includes conservation areas, is set out in the National Planning Policy Framework (the Framework). Paragraph 192 sets out matters which should be considered including sustaining and enhancing the significance of the heritage asset and the desirability of new development making a positive contribution to local character and distinctiveness. 7. It is considered raising the ridge height of No.20 would create an overbearing effect when viewed from the rear of the property when combined with the increased mass of the works required to facilitate the extension to the roof. This would also lead to an unbalancing effect when viewed in context with the adjoining property and other houses on this street. This would be a significant deviation from that of the existing roof form and is contrary to the design guidance contained within the House Extensions and External Alterations SPD, which seeks to avoid dormer windows projecting above existing ridge lines. 8. The proposed alterations would be visible to an extent from the streetscene, with the submitted drawings showing this increase in ridge height clearly, along with 2no rooflights. While the majority of the works would be visible from the rear of neighbouring properties rather than to the front, the BTMSPD explicitly states that part of the significance of the BTMs is the distinctive and cohesive styles of the houses which retain much of their original architectural interest and integrity. This character adds to the significance of the conservation area, and a gradual erosion of these elements can lead to an adverse effect on its significance as a heritage asset. As a result of the dormers requirement to raise the ridge height and add significant mass to the roof, I am unconvinced that the works would achieve the aims set out in the Framework, in that it would not respond to local character nor reinforce local distinctiveness. 9. My attention has been drawn by the appellant to two similar rear dormers on the same street approved by the Council. One is to the rear of No.18 next door to the appeal property approved in 2017, while the other is from No.34 approved in 1999. I did note the dormer next door during the site visit, as well as several other examples of dormers to the rear of properties visible from the rear of the appeal site. However, other than street view images, I have no evidence before me as to the specifics of those applications such as plans showing the ridge levels. As such I am unable to give full weight to those applications in the decision-making process and have determined the appeal based on the information provided. 10. The appellant also points out the footprint of the existing structure would not increase as a result of the works and considers the proposal would achieve a complimentary extension with notable architectural detailing. However, while I acknowledge that the footprint of the building would remain unaltered, for the Appeal Decision APP/L5810/D/19/3226275 3 reasons I have identified, the proposal would be at odds with the form and massing of the existing property. 11. For the reasons set out above, the proposal would not respect the character of the host dwelling. As such it would neither preserve nor enhance the character or appearance of the conservation area. Consequently, the proposal would not meet the weighty statutory requirements of the Act. Additionally, the proposal would not comply with policies LP1, LP3 and LP4 of the London Borough of Richmond Upon Thames Local Plan (2018) (LP) which, amongst other aspects, afford great weight to the conservation of a heritage asset when considering the impact of a proposed development on the significance of the asset and seek to ensure compatibility with local character including the relationship to existing townscapes and development patterns. 12. The works would affect a small section of the conservation area and therefore in terms of paragraph 193 of the Framework the harm caused to its significance would be less than substantial. The approach in paragraph 195 is that where a proposal would lead to less than substantial harm to the significance of a designated heritage asset, that harm should be weighed against the public benefits of the proposal. In this case the development would allow the re-ordering of the interior to meet the present occupier’s current family needs. This is clearly of personal benefit to the appellant, although I am not persuaded that it equates to a public benefit sufficient to outweigh the harm that I have identified. Recommendation 13. For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed. C McDonagh APPEAL PLANNING OFFICER Inspector’s Decision 14. I have considered all the submitted evidence and the Appeal Planning Officer’s report and on that basis the appeal is dismissed. S Ashworth INSPECTOR