Proposed two storey gable fronted extension, pitched roofs to existing front elevation dormers, rear extensions and internal alterations. The existing swimming pool will be infilled and the enclosure and plant room will be demolished

Appeal Decision Site visit made on 5 September 2017 by Richard S Jones BA (Hons) BTP MRTPI an Inspector appointed by the Secretary of State for Communities and Local Government Decision date: 21 September 2017 Appeal Ref: APP/M5450/D/17/3174117 Kimbolton, Priory Drive, Stanmore HA7 3HJ  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 Sam Patel against the decision of the Council of the London Borough of Harrow.  The application Ref P/5642/16, dated 5 December 2016, was refused by notice dated 30 January 2017.  The development proposed is described as “Proposed two storey gable fronted extension, pitched roofs to existing front elevation dormers, rear extensions and internal alterations. The existing swimming pool will be infilled and the enclosure and plant room will be demolished.” Decision 1. The appeal is dismissed. Preliminary matters 2. A Section 106 Obligation has been submitted in support of the appeal and the Council has been afforded opportunity to comment on it. I have considered both below. Main Issues 3. The main issues are:  whether the proposal would be inappropriate development in the Green Belt for the purposes of the National Planning Policy Framework (the Framework) and development plan policy;  the effect of the proposal on the openness of the Green Belt;  the effect of the proposal on the character and appearance of the area; and  if the development is inappropriate, whether the harm by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations, so as to amount to the very special circumstances necessary to justify the development. Appeal Decision APP/M5450/D/17/3174117 2 Reasons Whether the proposal is inappropriate development within the Green Belt 4. The appeal site lies within the Green Belt and comprises a large detached two storey dwelling with additional accommodation within its roof. It is set back from Priory Road and benefits from a relatively large rear garden, which includes an outdoor swimming pool. 5. Section 9 of the Framework sets out the Government’s approach to protecting Green Belt land. It states that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. The Framework advises that local planning authorities should regard the construction of new buildings as inappropriate. However, Paragraph 89 provides a limited number of exceptions to this general approach. This includes the extension or alteration of a building, provided that it does not result in disproportionate additions over and above the original building. The base position for calculating the enlargement of the original building is defined in the Framework as that which existed on 1 July 1948 or, if constructed after this date, as it was built originally. 6. The Council’s delegated report sets out the planning history of the appeal site and states that the original dwelling had a floor space of 304m². This has been increased by a two storey side extension (180.5m²) and by alteration to rear elevation with front and rear dormer windows (44m²), which were approved in 1964 and 1994 respectively. These have resulted in the floor space of the original building being increased by approximately 73%. 7. The proposed rear extension would add a further 78.1m² (25.6%) whilst the Council say that the front extension would add 7.3m² (2.4%). Cumulatively the percentage increase beyond the original floor space would be 101%. None of these figures are disputed by the appellant. Whilst I acknowledge that the appeal proposal would result in a relatively small amount of floor space being lost from the front of the dwelling, nevertheless, in combination with the previous additions, the appeal proposal would result in the floor space of the original building being roughly doubled. 8. I do not have details of the original volume of the building but details provided by the appellant show that following the demolition of the front chimney, dormer and canopy, the appeal proposal would add approximately 336m³ to the volume of the building as existing. This is clearly significant and in combination with previous additions would result in disproportionate additions over and above the original building. 9. The Framework does not suggest that the assessment can take account of the demolition or removal of other buildings within the appeal site, such as the modest floor space of the pool plant room. Moreover, on the basis of my interpretation of the plain words of the paragraph 89 of the Framework, an unimplemented planning permission (such as a permitted development right) cannot be considered as part of the baseline position and assessment. 10. It is argued that the proposal would not impact on one of the purposes of including land within the Green Belt, which is to prevent urban sprawl. However, as noted, paragraph 89 of the Framework makes clear that extensions to an existing building can constitute inappropriate development in Appeal Decision APP/M5450/D/17/3174117 3 the Green Belt where they involve disproportionate additions over and above the size of the original building. It is on this basis I conclude that the proposal represents inappropriate development that is, by definition, harmful to the Green Belt and in conflict with the Framework. I attach substantial weight to this harm. Openness of the Green Belt and character and appearance 11. Paragraph 79 of the Framework states that the essential characteristics of Green Belts are their openness and their permanence. 12. The two storey extension would run across the majority of the width of the rear of the dwelling and, at two storeys in height with gable features, would significantly enlarge its footprint and bulk. This greater physical presence would result in an appreciable reduction in the openness to the Green Belt. 13. Priory Drive itself is characterised by very large houses set within generous plots. The proposed front extension would replace an existing large front chimney stack feature and canopy entrance with a centrally positioned, Flemish gable type feature. Although striking in its appearance, given the scale and grand features of the existing house and the surrounding dwellings, the proposed front extension would not to detract from the character of the host dwelling or represent an incongruous addition to the street scene. 14. The depth of the rear extension would align with that of the existing family room to provide a more consistent rear back building line whilst the design would match that of the existing. The alterations to the roof, including additional gable features would also be subservient to the main roof form. The proposals for the rear would not therefore detract from the quality of the existing house and due to their positioning and level of existing boundary enclosure, would not be visible from the street scene. 15. I therefore find that the proposal would not be harmful to the character and appearance of the host dwelling or the surrounding area and in this regard would not conflict with Policy DM1 of the Harrow Council Development Management Policies (DMP). This states, amongst other matters, that all development proposals must achieve a high standard of design and layout. 16. Nevertheless, it is important to note that the openness of the Green Belt has a spatial aspect as well as a visual aspect and the absence of visual intrusion does not in itself mean that there is no impact on the openness of the Green Belt as a result. Indeed for the reasons I have explained, the proposal would result in a modest loss of openness to the Green Belt, contrary to national policy to protect it. This is a matter to which I attach moderate weight. Other considerations and the Green Belt balance 17. I have concluded that the proposed extensions to Kimbolton in combination with those that are existing, would amount to a disproportionate addition to the original dwelling. It would therefore amount to inappropriate development that would conflict with national and local policy to protect the Green Belt. 18. Moreover, the massing of the development and the scale of the volumetric increase would, in combination, harm the openness of the Green Belt. As openness is one of the most important attributes of the Green Belt this constitutes additional harm that further weights against the appeal proposals. Appeal Decision APP/M5450/D/17/3174117 4 Although I have found that development would not cause material harm to the character or appearance of the area, this is a neutral factor which does not weigh in favour of the proposals. 19. The Framework states that substantial weight will be given to any identified harm to the Green Belt, and that very special circumstances will not exist unless the potential harm to the Green Belt by virtue of inappropriateness, and any other harm, is clearly outweighed by other considerations. DMP Policy DM16 and Policy 7.16 of the London Plan are consistent with the Framework in this regard. 20. In terms of other considerations, I note that permitted development rights have not been removed for the appeal property and that a Certificate of Lawful Proposed Use or Development1 for a single storey pool house in the rear garden has been submitted in support of the appeal. The accompanying plans show that this would be a substantial structure with a footprint of approximately 124m² and a volume of 383.94m³. 21. The planning appeal statement of case explains that the appellant has volunteered to remove the existing swimming pool and to not construct the proposed outbuilding. On this basis it is stated that offsetting the volume of the proposed extensions against the swimming pool enclosure and demolitions (chimney, dormer, pool plant room, canopy and columns) would equate to a reduction of 63.55m³ in the volume of the building and a reduction of 24.32m² in its footprint. 22. Given that there is an existing swimming pool located in the rear garden and that the plans prepared for its enclosure have been granted a Certificate of Proposed Lawful Development, I find that there is a greater than a theoretical possibility that the development might take place. However, the fact that the appellant is willing to fill in the pool permanently suggests it is not a particularly important facility to him and this in turn raises questions over the likelihood that the enclosure would be built, even if this appeal were dismissed. This therefore limits the weight I have attached to this fallback position. 23. Moreover, the Section 106 Obligation submitted in support of the appeal only covenants to fill the existing swimming pool at the site and restore the land to garden and not to reinstate the pool at any time in the future. Given the nature of the open air pool, below ground level, this would have a very limited benefit to the openness of the Green Belt. 24. In any case, the annexed plan to the Obligation does not show the swimming pool at the site as stated in the covenant. The Council highlight other concerns but on this issue alone I find the Obligation to be flawed. I am therefore unable to attribute any weight to it in my decision. 25. Moreover, the Obligation does not covenant not to construct the proposed outbuilding, which is a structure which would clearly have a significant effect on the openness of this part of the Green Belt. Instead, the appellant has stated that a condition removing permitted development rights could be imposed for any future outbuildings which may have an impact on the openness of the Green Belt and which would also prevent the construction of the swimming pool enclosure. 1 Harrow Council Ref: P4138/16 Appeal Decision APP/M5450/D/17/3174117 5 26. However, this condition would not take effect unless the permission currently sought is granted and implemented. Therefore the swimming pool enclosure could be built and the permission implemented thereafter. This concern is heightened given that I have found the Section 106 to be flawed and that I cannot be certain that it could be enforced to ensure the swimming pool is infilled, or is not reinstated. 27. Thus, should this appeal be allowed, there would remain a physical possibility that both the appeal proposal and the fallback, or any other fallback position arising from permitted development rights, could be carried out. 28. For these reasons I find no other considerations in favour of the proposal that clearly outweigh the substantial weight required by the Framework to be given to any harm to the Green Belt. The very special circumstances necessary to justify the proposal do not, therefore, exist. 29. It is on this basis that the proposal would conflict with the above policies of the Framework, DMP Policy DM16, London Plan Policy 7.16B and Core Policy CS1.F of the Harrow Core Strategy. Conclusion 30. For these reasons, and taking all other matters into consideration, I conclude that the appeal should be dismissed. Richard S Jones INSPECTOR