Extensions and alterations to convert existing single-storey house into a two-storey house with rooms in the roof space incorporating integral garage and rooflights following partial demolition of existing house

Appeal Decision Site visit made on 26 November 2025 by John D Allan BA(Hons) BTP MRTPI an Inspector appointed by the Secretary of State Decision date: 04 December 2025 Appeal Ref: APP/K3605/D/25/3375040 High Trees, Bridgewater Road, Weybridge, Surrey, KT13 0EG • 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 N Pople against the decision of Elmbridge Borough Council. • The application Ref is 2025/1285. • The development proposed is extensions and alterations to convert existing single-storey house into a two-storey house with rooms in the roof space incorporating integral garage and rooflights following partial demolition of existing house. Decision 1. The appeal is dismissed. Main Issue 2. The main issue is the effects of the proposal upon the living conditions of neighbouring occupiers, particularly at 5 Bladen Close with regard to visual impact. Reasons 3. The appeal relates to a detached bungalow set centrally on a shallow but wide rectangular plot in a deeply recessed back-land position accessed from a long straight driveway leading from Bridgewater Road between two three-storey blocks of flats known as Eastwood and Holmsdale. The site backs on to the rear and side gardens of two-storey dwellings in Bladen Close. The area is entirely residential in character comprising mixed dwelling types and has a distinctive verdant quality derived from the significant amount of mature tree coverage, especially around the appeal site. This imparts a semi-rural feel and backdrop to the buildings that are seen surrounding High Trees, despite the area’s suburban location. 4. The appeal property has previously been extended and is set reasonably close to the plot’s front and rear boundaries, including those to the east at Bladens Close, particularly Nos 5, 6 and 7 which sit at the head of this small cul-de-sac development. Space to the north side of the existing dwelling provides a reasonably extensive garden area. Space to the south side includes a garage and shed, with associated gravel turning space. The proposal would significantly remodel the appearance and scale of the existing property by creating a two-storey dwelling with the first-floor described as being contained within the roof space, and with an expanded footprint, principally to the south side. This would entail removal of the existing garage and shed, as well as two semi-mature trees (a Cypress and a Appeal Decision APP/K3605/D/25/3375040 2 Laurel), both in fair condition set behind the dwelling and close to its south-east corner. 5. The Council has raised no objection to the architectural composition of the remodelled dwelling. Given the plot’s unique location and no direct association with any surrounding buildings, I have no reason to disagree. 6. Due to its deeply recessed position, the revised form of High Trees would have little visual impact when seen from distance along Bridgewater Road. From Bladen Close, its visual impact would be more noticeable. The dwelling would be considerably taller than the existing with a much more expansive and visually dominant roof scape. Its maximum ridge height is shown on the plans to be 8.3m, with its majority span measuring 7.3m high. This would be taller than the ridge heights of the two-storey dwellings adjacent in Bladen Close. The Council points to the dwelling’s position behind Nos 5 and 6 Bladen Close, and the degree of intervening vegetation, including some tall and mature trees. The extension and alterations to High Trees would undeniably be seen from Bladon Close, especially in the gap between Nos 5 and 6 over their adjoining single-storey garages. But, on balance, I share the Council’s view that, given the existing context, there would be little impact of significance upon the character and appearance of the general street scene when viewed from this aspect. This would however be heavily dependent upon the maintenance of an appropriate degree of vegetation and screening to enable sight of the extended dwelling to be shrouded to some degree. 7. The most significant and tallest part of the proposed extension would be to the south side of the existing dwelling and close to the shared boundary with 5 Bladen Close, with a separation of around 2.4m. No 5 is orientated perpendicular to High Trees with a two-storey gable facing the appeal site and a later single-storey side extension projecting west with windows facing the shared boundary at a distance of around 6m. The intervening space is part of No 5’s combined rear/side private garden area. 8. The appellant has provided an illustrated elevation showing the relationship between the extended form of High Trees, and the side extension to No 5 when looking north. When combined with the appellant’s ‘Daylight & Sunlight Report’ (the Report), it serves to demonstrate compliance with BRE Report 209 “Site Layout Planning for Daylight and Sunlight – a guide to good practice” in relation to daylight and sunlight to the nearest habitable rooms within No 5. I note concern from the occupier of No 5 that the Report does not consider the accurate configuration of the property’s windows. I also note the Council considered this and found no major difference between the fenestration pattern and that which was shown on the approved plans when No 5 was extended to the side. In the absence of any substantive evidence to contradict the Report’s findings, and the fact that the windows on the side elevation to the extension at No 5 appear secondary sources of outlook and light to the additional living space, I concur with the Council and am satisfied that levels of daylight and sunlight to No 5 would not be significantly impacted. However, the Report makes clear that its assessment relates to daylight and sunlight only and that its results must be seen in the context of all other planning considerations. 9. The Elmbridge Design Guide 2024 (EDG) deals with separation distances between buildings as they relate to their rear curtilages at its section 10.2.3. Due to the orientation of No 5, there is no direct back-to-back relationship with the appeal Appeal Decision APP/K3605/D/25/3375040 3 property. Regardless, the guidance specifically discusses distances relative to windows and outlook, with a particular focus on overlooking and privacy. The proposal involves only high level rooflights or else a single first-floor window that would be obscurely glazed and fixed shut to its rear elevation. I share the Council’s view that this would ensure existing levels of privacy at 5 and 6 Bladen Close would be sufficiently protected, with no prospect of any overlooking. The side facing elevation to the proposed extension of High Trees would feature only one equally high level rooflight ensuring privacy would also be protected to the nearest property to the south at 3 The Ponds. 10. The EDG does not directly address the issue of a building’s physical presence. The appeal site is reasonably constrained due to its back-land position, shallow depth, and extent of tree cover. However, by lying low, the existing dwelling’s design intuitively creates a respectful relationship with adjoining properties, particularly those closest to the east in Bladon Close and especially Nos 5 and 6. Its low rise form avoids any potential imposing presence resulting from its tight position close to the plot’s eastern boundary. As a consequence of a significantly enlarged dwelling on the appeal site, the important benefits of this, particularly upon the living conditions at No 5, would be lost through a combination of factors, as discussed below. 11. The extension to the south side of the dwelling would project into space that is currently open and would encroach beyond the building’s existing rear building line, closer to the shared boundary with No 5 and into an area that is already tightly constrained. Moreover, this element of the proposal would become the most dominant part of the remodelled dwelling, reaching a maximum height of 8.3m at ridge level. This is demonstrated by the appellant to be equivalent in height to the flat roof, three-storey block of flats nearby at Holmsdale, and would far exceed the height of most typical chalet-style properties where first-floor living space is usually contained within a roof with low eaves, conventionally sitting just above the head of any ground floor window or door opening. The scale and form of the proposed side extension would be significantly greater. 12. My impression overall is that, regardless of its pitched roof form, due to its size and position in such close proximity to the eastern boundary and adjoining side/rear garden of No 5, the extension to High Trees would impose itself at close quarters as a visually dominant and overbearing mass of built form when seen from the neighbouring property. Its harmful presence would be especially felt from the neighbour’s side/rear private amenity space, where its solid form would create an undue sense of enclosure, and one that would be out of keeping with the verdant qualities and generally spacious development pattern for the area. This would be detrimental to the neighbour’s enjoyment of their outdoor private amenity space and overall living conditions. 13. The appellant points to the existing conifer screen within the curtilage of No 5 along the shared boundary at this point. I accept that this would currently provide some screening and relief from the extension’s visual presence. However, it would be an unreasonable expectation for existing or future occupiers of No 5 to maintain a tall tree screen on the boundary to mitigate the presence of an unacceptably imposing extension. 14. I note the appellant proposes a row of pleached trees planted along the boundary to a height of 5m. However, no details of any such planting is shown on the Appeal Decision APP/K3605/D/25/3375040 4 proposed plans. Neither is there any expert opinion that this would be achievable in the space available or evidence to demonstrate that this approach is considered as an integral part of the proposal having regard to the position of the proposed extension and existing trees nearby. I am also mindful of the degree of maintenance that would be required to retain an effective screen, which could not be relied upon or reasonably controlled by condition in the long term. Regardless, I do not consider it appropriate to mitigate the impact of an intrusive development through planting. 15. When all is considered, I find the proposal would be harmful to the living conditions at 5 Bladen Close. As such, it would fail to achieve the high quality of design that is required by Policy DM2 of the Elmbridge Development Management Plan 2015, particularly as far as it seeks to protect the amenity of adjoining and potential occupiers and users. For the same reason there would be conflict with the National Planning Policy Framework’s objectives for achieving well-designed places. The reliance upon tree planting and vegetive screening to mitigate the visual impact of the scale of the proposed works when seen from Bladen Close adds further to my concerns. Conclusion 16. For the reasons given above, and having regard to all other matters raised, the appeal is dismissed. John D Allan INSPECTOR