Erection of a first floor ‘pilotis’ side extension incorporating a catslide roof, with associated alterations including new fenestration and fence

Appeal Decision by L McKay MA MRTPI an Inspector appointed by the Secretary of State Decision date: 22 September 2026 Appeal Ref: 6013018 2 Hart Dyke Road, Swanley, Kent, BR8 7DE • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Mr Oladimeji Kehinde against the decision of Sevenoaks District Council. • The application Ref is 26/01078/HOUSE. • The development proposed is erection of a first floor ‘pilotis’ side extension incorporating a catslide roof, with associated alterations including new fenestration and fence. Decision 1. The appeal is allowed and planning permission is granted for erection of a first floor ‘pilotis’ side extension incorporating a catslide roof, with associated alterations including new fenestration and fence at 2 Hart Dyke Road, Swanley, Kent, BR8 7DE in accordance with the terms of the application, Ref 26/01078/HOUSE, and the plans submitted with it, subject to the following conditions: 1) The development 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: OK_2 C, OK_3 C 3) The external surfaces of the extension hereby permitted shall be constructed using concrete tiles to match the tiles used on the existing dwelling, and painted render to match the colour of render used on the exterior of the existing dwelling. 4) The first floor rear window of the extension hereby permitted shall be installed with obscured glazing and fixed such that no part of that window that is less than 1.7 metres above the floor of the room in which it is installed shall be capable of being opened. The obscured glazing and fixed areas shall thereafter be retained in that form. Preliminary Matters 2. A revised description of development was agreed in writing between the Council and the appellant during the application process, and I have therefore used it above. 3. The most recent iteration of the National Planning Policy Framework (Framework) was published in August 2026. With regard to the main issues of this appeal, the relevant policies are not materially different from the previous iteration of the Framework. I am therefore satisfied that I can proceed without further consultation with the main parties since, with the above in mind, their respective cases would not be prejudiced. Appeal Decision 6013018 2 Main Issues 4. The main issues are the effect of the proposed development on the character and appearance of the area, and on the living conditions of the occupiers of 40 St Mary’s Road with particular regard to outlook and light. Reasons Character and appearance 5. The appeal site is in a residential area characterised by pairs of dwellings with part-hipped roofs and front dormers or gable features. Gaps between pairs are consistently relatively narrow, other than at corners where dwellings are set at right angles to each other with a larger gap at the corner. The set back of properties from the roads and relatively low eaves levels gives the area a spacious quality, particularly at road junctions. 6. No 40 has been extended to the side and rear, so is closer to the appeal dwelling than is characteristic on other corners locally. Therefore, the relationship is somewhat at odds with the character of the area. Nevertheless, there remains a moderate gap between the dwellings which is clearly visible in the street scene. A sense of space is created by the separation between the roofs of the properties. 7. The proposal would result in a first-floor addition with a gap beneath, supported by a wall along the boundary and enclosed by a gate to the front. It would be parallel to the side wall of the dwelling, leaving a small gap to the boundary, with a catslide roof following the line of the part-hipped roof. 8. The proposed catslide roof is not a feature found on this style of dwelling locally, however it is a design feature of other house styles in the area. Therefore, it would not be an alien addition to the street scene. It would continue the simple form of the existing roof below the existing eaves, at a similar pitch, and would not be as deep as the other catslide features in the area. Consequently, it would be considerably less bulky than those other features and the scheme previously dismissed at appeal1. Furthermore, it would not harmfully unbalance the symmetrical roof form of this pair of dwellings, as it would sit below the main roof. 9. Overall, therefore, the modest scale, simple design and significant set back from the front of the house would mean that the proposal would not appear unduly bulky or prominent in the street scene. Therefore, it would be relatively unobtrusive and create a satisfactory composition with the host property and its attached pair. 10. No 40 sits on a higher ground level than the appeal site. While the proposal would narrow the gap between the properties at ground floor level, this would not be unusual in the streetscene where gaps are often reduced by the presence of extensions, fences and hedges. The catslide roof would significantly limit the bulk of the proposal at first floor level, and with the level differences between the properties most of the gap between them at roof level would be retained. Consequently, I do not consider that this slight reduction in the gap would appear any more at odds with the regular pattern of development than currently, and it would not appear unduly cramped. 1 Appeal decision 6002820 Appeal Decision 6013018 3 11. Accordingly, the proposal would not harm the character and appearance of the area. Therefore, I find no conflict with Policy EN1 of the Sevenoaks Allocations and Development Management Plan (2015) (DMP) insofar as it requires high- quality design which, amongst other things, responds to the scale, height, materials and site coverage of the area and makes efficient use of land. Living conditions 12. I saw on site that No 40 has a kitchen window facing the side of No 2 and there is a sitting out area along the shared boundary. The side of No 2 limits the outlook from these areas, however they receive good levels of sunlight and daylight, being sited to the south of No 2. A single storey rear extension adjacent to the sitting out area contains a study space. This is set at a lower level than the main house and faces towards the rear part of the side elevation and the garden of No 40. The windows face the shared boundary fence, resulting in very limited outlook. The room is darker than others on the main ground floor level of the house but has a rooflight providing additional light. 13. Rooms in the roof space of No 40 have windows or roof lights providing views of the sky and local roofscape, and it is possible to look down towards the first-floor windows of No 2. However, due to their position and height, the outlook from these openings is largely across the roofscape and rear gardens of neighbouring properties. 14. The proposed extension would occupy the central part of the side elevation of the appeal property and project towards the shared boundary. It would be clearly visible from the sitting out area and kitchen window. The proposed extension would however be of limited scale in relation to the height and depth of the existing side elevation of No 2. Consequently, while it would be closer, the limited depth and scale mean that the change to outlook from these areas of No 40 would be modest. The kitchen also benefits from outlook through the dining space to the main garden area at the side of the property. The sitting out area of No 40 would retain its current outlook towards the front of the plot. 15. While the proposed extension would be visible from part of the main garden, it would be seen at an angle looking back towards the sitting out area and would not materially affect the open outlook from the main amenity space. As the outlook from the study area is already very restricted, and given its location relative to No 2, the additional built form proposed would have very little impact from that room. 16. Overall, therefore, the proposal would not appear unduly dominant or visually intrusive when viewed from No 40 and would not result in a harmful loss of outlook for the occupants of that property. 17. Given the relative orientation of two dwellings, the proposed extension would not result in additional shading of No 40. Daylight reaching the kitchen window of No 40 is already restricted by the presence of No 2, with light coming over the top of the side elevation and at an angle past the front and rear of that dwelling. Daylight to the study is primarily restricted by the proximity of the boundary fence. 18. The Council’s Residential Extensions Supplementary Planning Document (2009) (SPD) sets out a ’45 degree test’ which provides a guideline to measure the likely impact of an extension on daylight to a neighbouring property. The Council advises Appeal Decision 6013018 4 that the 45 degree test is met with regard to the relevant neighbouring windows and on the evidence before me I see no reason to disagree. 19. The submissions also refer to a ’25 degree test’ which does not appear to be part of the SPD, but may refer to Building Research Establishment (BRE) guidance. From the evidence before me it appears that the existing dwelling already breaches a 25 degree line drawn from the centre of the facing windows of No 40. The proposed extension would also breach this line in respect of the kitchen window of No 40, but would be lower in height than the existing dwelling. Therefore, it has not been demonstrated that it would result in any further material reduction in daylight compared with the existing situation. 20. The study windows of No 40 are sited towards rear of No 2 so would not face the proposed extension, and light to the rooflight would not be materially affected given the relative angles. Therefore, it has not been demonstrated that there would be any material impact on daylight to this room. Accordingly, the proposal would not result in a harmful reduction in either sunlight or daylight reaching No 40. 21. Consequently, I find that the proposal would not result in excessive visual intrusion or result in an unacceptable loss of light in relation to No 40. It would therefore retain adequate living conditions for the occupiers of No 40 with regard to outlook and light and would not conflict with DMP Policy EN2, which seeks to safeguard the amenities of occupants of nearby properties. Nor would there be conflict with the SPD in this regard. Conditions 22. Conditions are necessary in relation to implementation of the permission and compliance with the approved plans, in the interests of certainty. A condition to secure use of matching materials is necessary to safeguard the character and appearance of the area. 23. Overlooking would be possible between the proposed rear first floor window and the rear rooflights of No 40, to the detriment of the privacy of both sets of occupiers. A condition is therefore necessary to require the window to be obscure glazed and fixed, in order to mitigate this harm. There is no need to similarly restrict the front window as it would not directly overlook, or be overlooked by, neighbouring properties. Conclusion 24. The proposal would comply with the development plan and there are no material considerations that justify a decision otherwise than in accordance with the development plan. Therefore, for the reasons given above the appeal is allowed, subject to the conditions listed above. L McKay INSPECTOR