Change of use of the existing outbuilding to a one bedroom habitable granny annex and retained gym, entertainment room with addition of insulation

Appeal Decision Site visit made on 04 December 2024 by Nicola Davies BA DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 19 December 2024 Appeal Ref: APP/G5180/D/24/3352173 35 Cranbrook Close, Hayes, Bromley BR2 7QA • 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 James Huang against the decision of the London Borough of Bromley. • The application Ref is DC/24/02544/FULL6. • The development proposed is change of use of the existing outbuilding to a one bedroom habitable granny annex and retained gym, entertainment room with addition of insulation. Decision 1. The appeal is dismissed. Main Issues 2. The main issues raised by this appeal are the effect of the proposed development on the character of the area and flood risk. Reasons Character of area 3. The Council raise concerns that the form of development could potentially be severed from the main dwelling and be used as a self-contained dwelling unit. However, the completed householder planning application form makes it clear that the applicant, now the appellant, is seeking planning permission for development ancillary to an existing dwelling. 4. The proposal does not indicate any intention for the use of the outbuilding to be severed from the main dwelling house or access being other than via the dwelling house despite there being a side gate leading to the rear garden. The description of the proposed works provided on the householder planning application form indicate that the existing uses would be retained with a one- bedroom granny annex created within the existing outbuilding. This is the proposal that is before me. Therefore, I must consider the proposal as sought planning permission by the appellant. I, therefore, consider the proposal to be additional accommodation associated with the existing dwelling house even if it would have its own dedicated garden space within the rear garden. 5. The plans that support the application show a double bed within the bedroom which the Council considers would not meet the requirements pertaining to Appeal Decision APP/G5180/D/24/3352173 2 housing space standards. However, I have found the proposal to be an ancillary use to that of the main dwelling. As such, it is not a new dwelling to which the space standards would apply. 6. Consequently, I do not find that the proposed development would represent an overdevelopment of the site that would be considered out of character with the existing development in the locality. 7. For these reasons, I conclude that the proposed development would not be harmful to the character of the area. The proposal would, therefore not conflict with Policies D3 and D6 of the London Plan and Policies 7 and 37 of the Bromley Local Plan. These policies seek, amongst other matters, development to be of good design and to meet the criteria for accommodation for family members. Flood risk 8. The Environment Agency has advised that part of the rear of the site is located within Flood Zone 3, which is land defined as having a high probability of flooding. The existing outbuilding is located within this flood zone. The Framework sets out that whilst householder development would not be subject to the sequential and exceptions tests, a site-specific flood risk assessment should be provided for all development in Flood Zones 2 and 3. 9. The proposal is not supported by a flood risk assessment, therefore the flood risks posed by the development are unknown. As such, insufficient information has been submitted to provide reassurance that any such risk can be controlled to within acceptable levels. Therefore, the proposal does not demonstrate that harm from potential flooding would be obviated or mitigated. 10. It is advised that there would be no increase in the hardstanding area and there is landscaping in the western portion of the site. Furthermore, there is no historical groundwater flood event recorded. However, I cannot be certain that these factors would mitigate flood risk or would control flooding to within acceptable levels. As such, the proposal does not demonstrate that the occupants will remain safe for the lifetime of the granny annex. 11. For these reasons, I conclude that the proposed development would be harmful as a result of potential flood risk. The proposal would, therefore conflict with Policy SI 12 of the London Plan and Policy 115 of the Bromley Local Plan. These policies seek, amongst other matters, development to address existing flood risk and to reduce the impact of new development. Conclusion 12. Although I have found in favour of the appellant in regard of the first main issue, having regard to the above findings on the second main issue, the appeal should be dismissed. Nicola Davies INSPECTOR