Erection of a hip to gable loft extension to an existing semi-detached house to provide an additional bedroom and en-suite bathroom and a single storey rear extension

Appeal Decision Site visit made on 26 October 2016 by D J Barnes MBA BSc(Hons) DipTP MRTPI an Inspector appointed by the Secretary of State for Communities and Local Government Decision date: 2 November 2016 Appeal Ref: APP/F5540/D/16/3157203 5 Chestnut Grove, Isleworth TW7 7HA  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 Adam and Mrs Marie Mitton against the decision of the Council of the London Borough of Hounslow.  The application Ref 00246/5/P3, dated 24 May 2016, was refused by notice dated 4 August 2016.  The development proposed is the erection of a hip to gable loft extension to an existing semi-detached house to provide an additional bedroom and en-suite bathroom and a single storey rear extension. Decision 1. The appeal is dismissed insofar as it relates to the erection of a hip to gable loft extension to an existing semi-detached house to provide an additional bedroom and en-suite bathroom. The appeal is allowed insofar as it relates to the erection of a single storey rear extension and planning permission is granted for a single storey rear extension at 5 Chestnut Grove, Isleworth TW7 7HA in accordance with the terms of the application, Ref 00246/5/P3, dated 24 May 2016 and subject to the following conditions: 1. The development hereby permitted shall begin not later than three years from the date of this decision. 2. The development hereby permitted shall be carried out in accordance with the following approved plans so far as relevant to that part of the development hereby permitted: CGIH/P/02; CGIH/P/03 and CGIH/P/04. 3. The materials to be used in the construction of the external walls of the extension hereby permitted shall match those used in the existing building. 4. Notwithstanding the provisions of the Town and Country Planning (General Permitted Development) (England) Order 2015 (or any order revoking and re-enacting that Order with or without modification), no windows or other openings shall be constructed on the side elevations of the extension hereby permitted. Main Issue 2. It is considered that the main issue is the effect of the proposed development on the character and appearance of the host property and the surrounding area. Appeal Decision APP/F5540/D/16/3157203 2 Reasons 3. The appeal property is a 2-storey semi-detached dwelling situated within a predominantly residential area which includes properties of a similar type albeit there are variations in design. As noted by the appellants, the property is of a modest scale and originally possessed a utilitarian and simple design. The same characteristics apply to the surrounding dwellings of the same type. 4. The proposed development includes the erection of single storey rear extension which, excluding the pergola, the Council has confirmed could be erected as permitted development and is being erected (Ref 00246/5/P1). Also proposed are alterations to the property’s roof which are, again, being erected. These alterations comprise a change from a hipped to a gable roof form to enable a roof extension to the rear. The single storey rear extension with its pergola and the roof alterations are both physically and functionally independent. 5. Although the overall depth of the proposed rear extension would be greater than what could be erected as permitted development, it is concluded that the lightweight design, choice of construction materials, height and additional depth of the pergola, particularly taking into account the neighbouring extension, would not cause significant harm to the character and appearance of the host property and the surrounding area. Accordingly, this element of the appeal scheme would not conflict with Policies CC1, CC2 and SC7 of the Hounslow Local Plan 2015-2030 (LP). Amongst other matters these policies require development to creatively respond to and maintain the character of the area, to respect the surrounding established context and to be of high quality urban design. These policies are consistent with the National Planning Policy Framework's (the Framework) core principle of securing high quality design. 6. At the rear, the proposed roof extension would not be of a design which reflects other dormers or additions to the roofs of near-by properties, including 3A Chestnut Grove which the Council claims does not have permission. Further, the proposed extension would not conform to the guidelines contained in the Council’s Supplementary Planning Guidance: Residential Extensions Guidelines (REG), including by reason of the absence of set-backs from the side, ridge and eaves of the roof. These guidelines appear to reflect the requirements for roof dormers erected as permitted development. 7. I acknowledge the appellants’ comment that the REG only contains guidelines for extensions and other alterations to dwellings. However, the scale of the proposed roof extension would result in an unsympathetic addition to the property which would have a significantly detrimental effect on the character and appearance of the host property and similar types of dwellings within the surrounding area. Rather than a dwelling with a roof dormer, the bulk of this element of the appeal scheme would result in the extended property having the appearance of a 3-storey flat roof building when viewed from the surrounding gardens and from some locations along the footpath to the rear of the property. The modest scale and utilitarian and simple design of the host property, which is shared with the surrounding dwellings, would be lost. Further, by reason of scale and design, when viewed from the same locations the proposed roof extension would materially unbalance the appearance of this pair of semi- detached dwellings. The use of render for the external walls of the roof extension would not adequately mitigate the identified harm. Appeal Decision APP/F5540/D/16/3157203 3 8. By reason of the siting of No. 3A, the side and rear elevations of the proposed roof extension would not be particularly noticeable from the road but the alteration to the roof form would be visible. However, although contributing to the unbalancing of this pair of semi-detached dwellings, the change to a gabled roof form would provide an improved visual relationship between the property and No. 3A when viewed and would not be incongruous. However, the proposed rear roof extension would not have the same positive relationship. The poor design quality and siting of the dormer at No. 3A does not, in my judgement, justify the proposed roof extension and the significant harm caused to the character of the host property and the surrounding area. 9. Whether there is a need for a roof element above the eaves if a dormer meeting the Council’s guidelines was erected does not alter the assessment of the appeal scheme. Similarly, although other alterations of varying designs to roofs were noted during the site visit the detailed planning circumstances of these other schemes have not been provided. In any event, none of these observable schemes is of a similar scale and design as the proposed roof extension. I have noted the appellants’ desire to adopt a contemporary design approach towards the creation of the additional accommodation within the roofspace rather than the erection of a more traditional dormer. However, I have assessed this appeal scheme based upon the main issue and the significant harm which has been identified demonstrably outweighs this design approach. 10.Accordingly, it is concluded that the proposed roof extension, would cause significant harm to the character and appearance of the host property and the surrounding area and, as such, it would conflict with LP Policies CC1, CC2 and SC7 and the guidelines of the REG. In reaching this conclusion account has been taken of the lack of objection from local residents and other organisations to the appeal application but this matter does not alter the main issue which has been identified. However, the proposed rear and roof extensions are clearly severable by reason of being physically and functionally independent and I have reached different conclusions for both elements of the appeal scheme. Therefore, I intend to issue a split decision in this case. Conditions 11.The Council has suggested a number of conditions in the event that this appeal was successful which have been assessed against the tests identified in the Framework and the National Planning Practice Guidance. For reasons of proper planning, I agree with the Council that the proposed rear extension should be constructed in accordance with the submitted drawings and the external surfaces of the walls should match those of the property. Exceptionally, for reasons of protecting the privacy of the occupiers of neighbouring properties, a condition is necessary for permitted development rights to be withdrawn for the construction of new openings in the side elevation of the proposed rear extension. Accordingly, for the reasons given, the appeal in respect of the proposed single storey rear extension is allowed and but the appeal for the proposed hip to gable loft extension is dismissed. D J Barnes INSPECTOR