Appeal 6003530

The appeal is dismissed.

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.

I have considered the appeal based on the more precise revised description that was agreed between the main parties, this being ‘single storey side extension to existing detached garage to provide an additional garage with a pitched roof’.

The host dwelling at [site address] is a [name] listed building named ‘[address]’. Whilst not listed as a reason for refusal, I am required under section 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 to have special regard to the desirability of preserving the setting of the listed building. The proposed development would comprise an extension to a modern detached garage. It would be sited to the side of the existing garage furthest from the listed building and would be of a subordinate design, also incorporate matching materials. Consequently, I concur with the Council’s assessment in this regard, and the proposal would preserve the setting of the listed building.

The main issue is whether the proposed development would be acceptable in terms of flood risk.

The appeal site is located within [name] 3b, ‘The Functional Floodplain’. ‘Table 2: Flood risk vulnerability and flood zone ‘incompatibility’’ in the Planning Practice Guidance (PPG) indicates that development should not be permitted in [name] 3b other than for essential infrastructure or water compatible development that has passed the exception test or designed and constructed to meet specified requirements.

Notwithstanding the above, Paragraph 176 of the National Planning Policy Framework (the Framework), supported by footnote 62, identifies that applications for some minor development, including householder development, should not be subject to the sequential test, nor the exception test, but in [name] 2 and 3 should provide a site-specific flood risk assessment (FRA).

The PPG confirms that even minor developments can affect flood risk within or beyond the property, particularly in areas susceptible to flooding and that applications for minor development involving extensions or additions should still meet the requirements to provide a site-specific FRA. As a minimum, the assessment needs to show that the development will be safe for its users for the intended lifetime of the development, without increasing flood risk elsewhere, and be sufficiently flood resistant and resilient to the level and nature of the flood risk1.

The appellant’s FRA confirms that the proposed development would not be used for sleeping accommodation, that the floor level would match the existing garage floor level and that all new rainwater pipes would discharge into a new soakaway. These matters relate to making the site safe for its users and drainage on the site only.

However, even though the proposed development would be placed on an area of existing hardstanding, this area is currently a space that flood water could inundate as part of the floodplain. The mass of the proposed development would reduce floodplain storage space with the potential to increase flood risk elsewhere through the deflection or constriction of flood flow. In this regard, the PPG2 sets out that site-specific FRAs should assess such impacts and demonstrate how mitigation measures have addressed them. Where flood storage from any source of flooding is to be lost as a result of development, on-site level-for-level compensatory storage, accounting for the predicted impacts of climate change over the lifetime of the development, should be provided.

Flood storage compensation has not been addressed in the appellant’s FRA. Therefore, and even accounting for the modest scale of development, it has not been demonstrated that flood risk would not be increased elsewhere as required by Paragraph 181 of the Framework.

I conclude that the proposed development would be unacceptable in terms of flood risk. In that regard, it would conflict with the requirements in Policy 84 of the [site address] District Local Plan Review (1994) for proposals not to increase flood risk. For the reasons set out, the proposal would also conflict with the relevant provisions of the Framework and the PPG.

For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed.