First floor side and rear extension with rear infill extension at ground floor level. Conversion of garage to habitable accommodation and changes to fenestration

Appeal Decision Site visit made on 21 November 2025 by G Sylvester BSc (Hons) MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 01 DECEMBER 2025 Appeal Ref: APP/Q3630/D/25/3374004 75 Almners Road, Lyne, Chertsey, Surrey KT16 0BH • 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 Chris Aldridge against the decision of Runnymede Borough Council. • The application Ref is RU.25/0770. • The development proposed is a first floor side and rear extension with rear infill extension at ground floor level. Conversion of garage to habitable accommodation and changes to fenestration. Decision 1. The appeal is dismissed. Main Issues 2. The main issues in this appeal are: • Whether the proposal would be inappropriate development in the Green Belt having regard to any relevant development plan policies and the National Planning Policy Framework (“the Framework”). • The effect of the proposal on the openness of the Green Belt. • If the proposal is inappropriate development in the Green Belt, whether the harm by reason of inappropriateness would be clearly outweighed by other considerations so as to amount to the very special circumstances necessary to justify it. Reasons Whether inappropriate development 3. Policy EE14 of the Runnymede 2030 Local Plan Adopted July 2020 (“the RLP”), states that the extension of a building is not inappropriate development in the Green Belt, provided it does not result in disproportionate additions over and above the size of the original building. This is consistent with the exception in Framework paragraph 154.c). 4. Neither the RLP nor the Framework define what is meant by a disproportionate addition. Therefore, it is a matter of planning judgement as to whether the appeal proposal would amount to a disproportionate addition over and above the size of the original building. RLP Policy EE14 indicates several relevant factors in making that judgement, including any previous extensions or enlargements, the existing and proposed floorspace and built footprint, and changes in the mass, bulk and height of a building. Appeal Decision APP/Q3630/D/25/3374004 2 5. The Framework defines an original building as a building as it existed on 1 July 1948 or, if constructed after that date, as it was built originally. As I have not been referred to an alternative definition in the RLP for an original building, I have no basis to depart from the one in the Framework. 6. The appeal relates to a 2-storey dwelling with a rear projecting flat roofed wing and a side projecting flat roofed garage. Before me are date-stamped drawings from a 1956 planning permission for a dwelling and pitched roofed garage that clearly relate to the appeal dwelling, which has a narrow forward projecting wing across both storeys on its facade. They show the dwelling approved in 1956 as having a more or less square footprint and none of the single storey flat roofed projections that currently exist. Whether the detached garage shown on those drawings was ever built is unclear. 7. The evidence before me indicates that the existing attached flat roofed garage was a later addition to the building. It closely corresponds to a carport structure approved in 1961 on land that would have been occupied by the approved garage. The flat roofed rear wing appears to consist of later additions to the building that are joined together. Part of it is built from brick and closely matches the drawings of an extension granted planning permission in 1973. The other part appears to be of recent construction with blockwork walls and likely corresponds to that indicated as being granted a lawful development certificate in 2024, ref. RU.24/1169. 8. Consequently, in assessing the proposal against RLP Policy EE14 and the Framework’s exception in paragraph 154.c), the evidence before me indicates that the original building is that shown on the drawings of the 1956 planning permission. As such, those flat roofed rear wings and the attached garage are later additions and not part of the building as it was originally built. The existing building on the appeal site is therefore larger than the original building. 9. It is unclear how the appellant has defined the original building or why their calculations, which are tabulated in the Officer Report, show the original building and the existing building as the same size. I share the Council’s view that those calculations do not appear to account for those subsequent extensions to the original building that have increased its size. 10. Nonetheless, as a best-case scenario for the appellant, I have taken their calculations of the size of the existing building as a proxy for the size of the original one. In doing so, those calculations show that the proposed extension would increase the floor area by approximately 43% over and above that of the original building and an even greater increase in volume. Together, those figures are a clear indication that the proposed development would result in a disproportionate addition over and above the size of the original building. 11. Numerical calculations are not the only way to assess whether a proposed extension would be a disproportionate addition to an original building. As set out above, RLP Policy EE14 refers to several other relevant factors including changes in the mass, bulk and height of a building, including its roof form. 12. In this instance it is clear from the drawings that the proposed extension would add considerable additional built form to the principal 2-storey core of the building, at an elevated level directly above the existing flat roofed wings. Whilst the proposed extension would not exceed the maximum height of the building’s roof, that extra bulk and mass would result in a significant increase in the size of the original Appeal Decision APP/Q3630/D/25/3374004 3 building. As such, it would constitute a disproportionate addition over and above the size of the original building. 13. The tests of proportionality in RLP Policy EE14 and the Framework’s exception in paragraph 154.c), are narrowly set against the size of the original building to be altered or extended, and not against the sizes of other buildings in the area. Therefore, even if considerably larger than the appeal dwelling in its proposed extended form, the sizes of those existing dwellings close to the appeal site have no bearing on my assessment of proportionality in those terms. 14. The Council’s refusal reason refers to the exception in Framework paragraph 155, which relates to development that utilises grey belt land. However, as there is no substantive evidence of a demonstrable unmet need for development of this type, that exception would not apply. 15. Consequently, for the reasons given above, the proposed development would result in a disproportionate addition over and above the size of the original building. As such, it would be inappropriate development in the Green Belt, contrary to RLP Policy EE14 and the exception in Framework paragraph 154 c). Green Belt openness 16. Openness is an essential characteristic of the Green Belt, and a fundamental aim of Green Belt policy is to keep land permanently open. Green Belt openness has spatial and visual aspects. In spatial terms the built form of the proposed extension would harm openness by occupying space at an elevated level above the flat roofed wings, where built form does not currently exist. Although the proposed extension would be seen amongst some relatively large dwellings in the area, its bulk and massing would amount to a significant addition to the building that would visibly cause a harmful loss of Green Belt openness, albeit in relatively localised views from Almners Road and nearby properties. For those reasons, I conclude on this issue that the appeal proposal would result in a moderately harmful loss of openness in the Green Belt. Other considerations 17. It is reasonable to suppose that the proposed extension would be important to the appellant in enhancing the quantity and quality of the living space in the dwelling. However, the planning process is mainly concerned with managing development in the public interest, which in this instance includes the great importance attached to Green Belts and their openness and permanence. The harm I have identified to the Green Belt would likely remain long after those personal circumstances cease and they carry modest weight in favour of the appeal proposal. Other Matters 18. I am aware that the Grade II listed building of Almner's Priory is nearby. I have had regard to my statutory duty under Section 66(1) of the Planning (Listed Building and Conservation Areas) Act 1990, to pay special attention and have regard to the desirability of preserving its setting. The listed building is situated on the opposite side of the road to the appeal site and is set well back from the road behind a spacious verdant lawn. Given the distance of separation between them it would preserve the setting of the listed building. Appeal Decision APP/Q3630/D/25/3374004 4 Green Belt Balance and Conclusion 19. The proposal would be inappropriate development in the Green Belt and would harm Green Belt openness. Therefore, it should not be approved except in very special circumstances. Such circumstances will not exist unless the totality of the harm to the Green Belt is clearly outweighed by other considerations. The Framework requires me to give substantial weight to any harm to the Green Belt 20. In this instance the harm to the Green Belt would not be clearly outweighed by other considerations. Consequently, the very special circumstances necessary to justify the proposed development do not exist. Therefore, it conflicts with the Framework’s policies that seek to protect Green Belts, and it conflicts with RLP Policy EE14 and the development plan as a whole. There are no material considerations, including the provisions of the Framework that outweigh that finding. Accordingly, the proposal is unacceptable, and the appeal should be dismissed. G Sylvester INSPECTOR