Erection of an oak-framed building to be used as a granny annexe

Appeal Decision Site visit made on 13 April 2026 by S Manson DipTP MRTPI Decision by John Morrison BA (Hons) MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 30 April 2026 Appeal Ref: 6005662 336 Main Road, Biggin Hill, Westerham TN16 2HL • 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 Kim Wood against the decision of the Council of the London Borough of Bromley. • The application Ref is 25/04574/HPA. • The development proposed is the erection of an oak-framed building to be used as a granny annexe. Decision 1. The appeal is dismissed. Appeal Procedure and Preliminary Matters 2. The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal. 3. The proposed building would be within the curtilage of and close to the host dwelling. It would comprise a bedroom, bathroom, kitchen and living area. There is no information before me as to how the annexe would be occupied in conjunction with the host dwelling other than it would be for a retired member of the incumbent family. Nevertheless, the annexe would share the existing driveway and parking arrangements, and no separate garden or private amenity space is proposed. It is also sufficiently clear that the appellant has applied for a building to be used as an annexe and not a dwelling. Its occupation could be subject of a planning condition. Notwithstanding the Council’s concerns in this regard, I have considered the appeal as seeking planning permission for an annexe. 4. With this in mind, any activity or noise arising would be limited to and comparable with typical household levels. As such, it would not conflict with Policy 37 of the Local Plan, London Borough of Bromley, Planning Division, 2019 (LP), which amongst other things, requires development to respect the amenity of occupiers of neighbouring buildings by ensuring they are not harmed by noise and disturbance. 5. The Council’s second reason for refusal expresses substantive concerns over the effect of a dwelling on the character of the area. This is unsubstantiated in the evidence. I have not therefore, taking the above into account, considered it any further. Appeal Decision 6005662 2 Main Issues 6. The main issues are a) whether the proposal would be inappropriate development in the Green Belt; b) its effect on the openness of the Green Belt; and c) if the scheme is inappropriate development, whether the harm by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations, as to amount to very special circumstances required to justify it. Reasons for the Recommendation Inappropriate Development 7. In regard to Green Belt development, the National Planning Policy Framework (Framework) sets out, amongst other things, that development is inappropriate, unless it falls within a given set of exceptions. Policy 49 of the LP reflects the stance of the Framework in this regard. For the purposes of Green Belt policy, and as a domestic adjunct, an outbuilding can be considered as an extension. In this regard, paragraph 154 (c) of the Framework sets out that the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building is not inappropriate development. Policy 51 of the LP makes an allowance for similar, explaining that the floor area over the original building cannot be any more than 10% as ascertained by an external measurement. 8. I don’t have calculations of the amount of additional built form that has been added to the dwelling in the past but understand it has been extended over one and two storeys to the side and a single storey outbuilding has been erected in the corner of the plot adjacent the back edge of the highway. On visual inspection, having regard to the host building itself, the land take of the additions listed would more likely than not equate to being greater than 10% as per Policy 51. The overall substance, height and thus volume of the additions would almost certainly be close to, if not disproportionate already in the context of what I gather from the evidence is the original building. Having regard then to the size and substance of the proposed annexe here, that situation would only be greater. 9. Paragraph 154 (d) of the Framework concerns the replacement of a building, provided the new building is in the same use and not materially larger than the one it replaces. I am unclear as to whether one could consider the two shipping containers currently within the garden a building. If they are, and a suitably robust mechanism could secure their removal through any planning permission then I would be unsure whether, given the current incidental use of them and the intended ancillary/residential use of the annexe, they would be considered the same use. Should this be the case, and having regard to their rectangular boxlike shape, composition and thus volume, it strikes me that the more sprawling, multi-faceted and pitched roof annexe building would present as being materially larger both on paper and in reality. 10. With this and the above in mind, the appeal scheme would be inappropriate development in the Green Belt. It would accordingly conflict with the Framework’s stance thereon as well as, by association, the aforementioned policies of the LP as far as they seek to protect the Green Belt from harmful development. Appeal Decision 6005662 3 Openness 11. Openness is a fundamental attribute of the Green Belt and comprises both spatial and visual elements. Spatial openness is generally taken to refer to the absence of built form. The appeal proposal would involve the removal of two steel containers and their replacement with a detached building of materially greater height and footprint. Regardless of the parties’ differing views on the lawfulness of the existing containers, the proposed development would introduce a more substantial built form which would inevitably reduce the spatial openness of the Green Belt. 12. Given the site’s semi-rural and largely exposed location fronting Main Road, the annexe would have a noticeable visual presence. Positioned forward of the dwelling and alongside an existing detached garage, adjacent the highway, it would appear as an additional and prominent form of development. While the containers are not ideal, their limited height and subdued colouring, in combination with their position only marginally above the boundary wall, mean that they are currently of limited visual prominence. By contrast, the proposed building would be more conspicuous and as such would diminish the visual openness of the Green Belt. This harm would arise in addition to the proposal’s inappropriateness and further conflict with the Framework’s position on protecting openness as also directed to by the aforementioned policies. Other Considerations 13. A previous proposal for a triple garage in the same location as the appeal scheme was dismissed on appeal. The Inspector acknowledged that the replacement of a lorry body and a large steel container would result in an improvement to the visual amenity of the site, but that this benefit could not be afforded determinative weight in the absence of clear evidence that they were lawful. I note that some time has passed between then and now, but I cannot be certain that the containers that are on site and proposed for removal as part of this scheme are the same as those referred to in my colleague’s decision on the triple garage. Which were identified as a lorry body and large steel container on a concrete hardstanding. The current arrangement is clearly two rectangular box type shipping containers of similar appearance. Moreover, I do not have any confirmative evidence, such as a certificate of lawfulness, setting out that the current situation on site is lawful and thus the containers are immune from enforcement action. 14. With this ambiguity in mind, I find myself in a very similar situation to my colleague in terms of whether the containers are lawful through the passage of time or otherwise. I thus attach limited weight to this matter, notwithstanding methods that might be procedurally correct, that may be possible to use to secure their removal and the fact that the design of the annexe building would, in the visual sense, be far more pleasing to the eye than two steel containers. 15. The garage that is currently on site was allowed on exactly this basis, but in that case it seems the Inspector was satisfied, through whatever evidence was before them, that the containers being replaced were lawful. That is a package of circumstances in and of themselves at the time which do not, for the reasons I have explained, have sufficient bearing and influence on the case before me. 16. It is suggested that the proposal would provide specialist accommodation for an elderly family member, a form of housing which the Council would, in principle, support in an appropriate location. However, no substantive evidence has been Appeal Decision 6005662 4 submitted to demonstrate that the proposed building would function there as. Beyond the intended occupation by a retired family member. There is no indication that it would incorporate specific design features or facilities that would distinguish it from a conventional annexe, nor has any evidence been provided to quantify an unmet need for such accommodation within the Borough. Even if some limited benefit were to arise, this would be modest, given that it would relate to a single unit serving a private need, and any associated economic benefits from construction would be limited and temporary. Accordingly, only limited weight can be attributed to these considerations. Conclusion and Recommendation 17. The appeal scheme would constitute inappropriate development in the Green Belt. It would also result in a reduction in openness, both spatially and visually. In accordance with the Framework, I give substantial weight to this harm. In totality, and for the reasons I have set out, the weight ascribed to the other considerations would be insufficient to clearly outweigh it. Accordingly, the very special circumstances necessary to justify the proposed development do not exist. 18. The proposal would therefore conflict with the development plan as I have set it out above and other material considerations, including the provisions of the Framework, do not indicate a decision other than in accordance therewith. I therefore recommend that the appeal should be dismissed. S Manson APPEAL PLANNING OFFICER Inspector’s Decision 19. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed. John Morrison INSPECTOR