Construction of a mansard roof extension to existing flat roof

Appeal Decision Site visit made on 16 May 2017 by Stephen Normington BSc DipTP MRICS MRTPI FIQ FIHE an Inspector appointed by the Secretary of State for Communities and Local Government Decision date: 02 June 2017 Appeal Ref: APP/K5600/D/17/3170448 6 Kingsley Mews, London W8 5PY  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 Soon Yeng Chiam against the decision of The Council of The Royal Borough of Kensington & Chelsea.  The application Ref PP/16/06663, dated 4 October 2016, was refused by notice dated 6 December 2016.  The development proposed is the construction of a mansard roof extension to existing flat roof. Decision 1. The appeal is dismissed. Main Issues 2. The main issues are:  Whether the proposed development would preserve the character and appearance of the De Vere Conservation Area.  The effect of the proposed development on the living conditions of the occupants of No 41 Cornwall Gardens with particular regard to outlook. Reasons Character and appearance 3. The appeal property comprises a two storey, flat roofed, mid-terrace mews dwelling located within Kingsley Mews which is a cul-de-sac containing seven similar dwellings. Immediately to the east is Kynance Mews, also comprising of similar dwellings, which is connected to properties in Kingsley Mews and together form an elongated terrace. 4. The mews containing the appeal property is located between much larger four and five storey terraced properties on Eldon Road to the north and Cornwall Gardens to the south. Whilst several of the properties on these streets have had mansard roof extensions, none of the properties in Kingsley Mews and those in close proximity on Kyance Mews have such roof extensions. Although the roof line of the terrace of the mews is broken by isolated structures such as flues and access covers, including a small brick built roof access structure at No 5 Kingsley Mews, the overall appearance of the roof of the mews in the vicinity of the appeal property is predominantly that of an unbroken flat roof line. Appeal Decision APP/K5600/D/17/3170448 2 5. The proposed development would involve the construction of a mansard roof to provide an additional storey to the appeal property which would contain two windows in each of the north and south elevations with blank side elevations. It would occupy the full width of the property. 6. The proposed mansard roof would break the existing roof line of the terrace as a whole and would appear at odds with the distinct flat roof and horizontal profile of the block thereby unacceptably interrupting the flow of the roof structure. Although the adjacent property at No 5 has an access structure, this occupies only a small part of the roof and cannot be readily seen from the Mews itself. By contrast, the proposed mansard roof, in occupying the full width of the property, being positioned directly behind the front parapet, and being considerably higher than the structure at No 5 would be prominent in views from the Mews where it would appear as an incongruous and bulky addition. 7. The Council has referred to the De Vere Conservation Area Appraisal that identifies mansard roofs as an example of an alteration that causes harm to mews properties. Whilst I recognise that there are many examples of mansard roof extensions in the vicinity, the terraces in the vicinity forming Kingsley Mews and Kyance Mews appear to be free from such additions and therefore the original flat roof profile of these terrace blocks is an integral part of the character of this part of the conservation area. 8. The proposed development would form a stark and isolated addition to the characteristic flat roof profile that would cause unacceptable harm to the appearance and architectural integrity of the appeal property and this part of the terraced block. Consequently, taking all of the above matters into consideration, the proposal would fail to respect the distinctive character of this building and its relationship with this part of the terraced block thereby causing harm to the character and appearance of the area. 9. I have taken into account the appellant’s view that the roof of the terrace block is cluttered with various protrusions such as flues, rooflights and vents and as such, the roof line is not impaired. However, these structures are relatively small isolated additions that cannot be readily seen from either Kingsley Mews or Kynance Mews. As such, they do not detract from the overall flat roof profile of the terrace mews. 10. In any event, Policy CL8(viii) of the Royal Borough of Kensington and Chelsea Consolidated Local Plan (2015) (Local Plan) states that the Council will resist additional storeys on terraces that are already broken only by isolated roof additions. Notwithstanding the fact that the overall appearance of the roof mews is predominantly that of an unbroken flat roof line, even if I were minded to accept the appellant’s view, the proposed development would not accord with this part of the policy. 11. Against that background, I conclude that the proposed development neither preserves nor enhances the character or appearance of the De Vere Conservation Area. In the context of the National Planning Policy Framework (the Framework) great weight should be given to the conservation of a designated heritage asset. Although I consider the harm to be less than substantial, any harm should require clear and convincing justification. In this case there are no public benefits that would outweigh the harm. Appeal Decision APP/K5600/D/17/3170448 3 12. Accordingly, the proposal conflicts with section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 and would not accord with paragraphs 131 and 132 of the National Planning Policy Framework. It would also be contrary to Policies CL1, CL2, CL3, CL8 and CL11 of the Local Plan. These policies, amongst other things, require that development should respect existing character and context of existing buildings and preserve or enhance the character or appearance of the conservation area. In addition, the Council will resist additional storeys where the exiting roof is unimpaired by extensions or already broken only by isolated roof additions. Living conditions 13. The rear outrigger wing of No 41 Cornwall Gardens has a window, which the appellant indicated serves a bedroom, that would be at a similar level to, and face towards the proposed development. The appellant indicates that the proposed mansard roof would be positioned approximately 5m from the window at No 41. 14. I agree with the Council’s view that, given the fact that the appeal property is located to the north of this window and the intervening distance, the proposal would not cause any significant loss of light to this window. Although the proposed mansard roof would interrupt the outlook from the window in direct views, substantial oblique views over remaining undeveloped flat roof of the terraced mews would be retained. Whilst there would be some degree of enclosure, taking this factor into account and the intervening distance between the window and the proposed mansard roof, I do not consider that this would be of an extent to cause any demonstrable harm to the living conditions of the occupants of No 41. 15. I therefore conclude that the proposed development would not cause a loss of outlook or sense of enclosure that would cause demonstrable harm to the living conditions of the occupants of No 41 Cornwall Gardens. Consequently, there would be no conflict with Policy CL5 of the Local Plan. This policy, amongst other things, requires that development should ensure good living conditions for the occupants of neighbouring buildings and that there is no harmful increase in the sense of enclosure to existing buildings and spaces. Conclusion 16. Although I have found that the proposed development would not cause harm to the living conditions of the occupants of No 41 Cornwall Gardens this does not outweigh my findings that the proposal would not preserve the character or appearance of the De Vere Conservation Area. For the above reasons, taking into account the development plan as a whole based on the evidence before me and all other matters raised, I conclude that the appeal should be dismissed. Stephen Normington INSPECTOR