Erection of a glass conservatory extension

Appeal Decision Site visit made on 24 August 2026 by John D Allan BA(Hons) BTP MRTPI an Inspector appointed by the Secretary of State Decision date: 15 September 2026 Appeal Ref: 6012278 2 Tregaron Avenue, Hornsey, Haringey, London N8 9EY • 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 B Connor against the decision of the Council of the London Borough of Haringey. • The application Ref is HGY/2026/0783. • The development proposed is the erection of a glass conservatory extension. Decision 1. The appeal is dismissed. Preliminary Matter 2. During the course of the appeal, the revised National Planning Policy Framework 2026 (the Framework 2026) was published. Both parties were invited to comment about the relevance of the Framework 2026 to their case. Main Issues 3. The main issues are the effects of the proposal upon the character and appearance of the host property and wider area, and upon the living conditions at 4 Tregaron Avenue with particular regards to visual impact and privacy. Reasons Character and Appearance 4. The appeal relates to a detached, part two-storey part three-storey dwelling with a lower ground floor to the rear leading to a modest sized private garden set below street level. The immediately adjoining property to the east side at No 4 is two- storey front and rear. No 2 has previously been extended with side and rear extensions and is separated from the side boundary and flank wall of No 4 by the width of a narrow passage. The area is residential in character comprising a mix of property types and styles, many of which have been altered in a variety of forms beyond their original appearance. 5. The appeal property has an existing narrow rear outrigger across part of its rear elevation which reads as a flat roof, three-storey feature with a terrace above when viewed from the garden and its surrounds. To the side of this and across the remaining width of the property nearest to No 4 is a flat roof extension at lower ground and ground floor levels. The proposal is to add a contemporary, frameless Appeal Decision 6012278 2 glass conservatory as a reading room, infilling at first-floor level over the existing rear extension to a depth of just over 3.5m, and to be accessed from one side via an internal corridor within the outrigger. The extension, described as having a flat glass roof, which would be tucked below the eaves to the house, would be set back from the parapet of the existing flat roof area by 600mm to the rear and side nearest to No 4. 6. The appellant has described the seamless structural glass construction of the proposed conservatory, which I accept would be both lightweight in appearance and subordinate in scale relative to the size of the dwelling overall. As a sedentary glazed box, the addition would be fairly non-intrusive without significantly impacting the architectural composition of the existing building. However, as an internal living space it would likely function with fixtures and fittings, including illumination from within during hours of poor daylight and darkness, all of which along, with its occupancy by any number of persons, would be evident from outside due to its visual transparency. As such, it would not always be invisible to the eye, instead at times appearing as an active and uncontained illuminated box. 7. A suggestion by the appellant that the proposal would be an improvement to the dwelling’s rear elevation is unfounded. I saw nothing about the appearance of the existing dwelling to be visually unappealing or which would significantly benefit from the extension. My overall impression is that despite its fully glazed form, the proposal would add a functioning living space that would be openly seen from the wider surrounds of neighbouring properties. Due to its size, elevated position and choice of materials, the conservatory would appear as an incongruous adjunct that would be both visually intrusive and alien in its setting, neither reflecting nor complementing the form of the building. As such it would detract from the character and appearance of the existing dwelling to the detriment of the wider visual amenities of the surroundings. Living Conditions 8. No 4 is unextended to the rear and sits close to the appeal property, with its rear elevation marginally set behind the two-storey scale of No 2. The proposed conservatory would project over 3.5m beyond the rear elevation of No 4, nearest to a first-floor window which is understood to serve a bedroom. 9. As a lightweight glazed structure, the extension would be unlikely to significantly impact levels of daylight to any living spaces within No 4. Due also to the north facing rear elevations of these properties, there would be little, if any, overshadowing or impact upon levels of direct sunlight to the neighbouring property. 10. The side wall of the conservatory is proposed to be obscurely glazed up to a height of 1.7m above its floor level. This would mitigate any direct overlooking from the internal space towards No 4 and could be secured by condition. However, because of the extension’s transparency, its use and function would not go unnoticed. As such, there would be a clear and unreasonable perception of being overlooked, both at a common first-floor level between the neighbouring properties from within the nearest living space at No 4, and from above within the garden area set nearest to the rear elevation of the neighbouring property, where levels of privacy can usually be expected to be at their highest and enjoyed without fear of intrusion. Appeal Decision 6012278 3 11. In addition, due to its depth and position close to the boundary with No 4, the physical presence of the extension associated with its use would create a sense of additional built form that would be visually intrusive at close quarters in the outlook from the nearest first-floor window and from the nearest adjoining garden space. This in turn would create an overbearing impression that I consider would be further harmful and unneighbourly. Conclusions 12. By failing to sensitively integrate with its surroundings through preservation of the character and appearance of the dwelling and wider area, and by failing to maintain acceptable living standards for the neighbouring occupiers, there would be clear conflict with Policies DM1 and DM12 of the Development Management Development Plan Document, adopted in 2017, and with Policy SP11 of Haringey’s Local Plan Strategic Policies 2013 - 2026, adopted in 2013. Between them these seek to ensure that new development is of the highest quality that respects and contributes to local character and takes account of the privacy and amenity of neighbouring uses. For the same reasons, notwithstanding the sustainable qualities of the proposal in terms of the site’s location and the innovative design of the conservatory, the proposal overall would fail to accord with all the principles required for making effective use of land and achieving well-designed places within the national decision-making policies L2 and DP3 of the Framework 2026. 13. Therefore, for the reasons given, the appeal is dismissed. John D Allan INSPECTOR