Appeal 3340701

The appeal is dismissed.

The main issues are: • the effect of the proposal on the character and appearance of the existing dwelling and surrounding area; and • the effect of the proposal on flood risk.

The appeal property is a three storey, mid-terrace townhouse location in a row of similar properties. The existing terrace has a flat roof and adjoins a four-storey flat roof building comprising maisonettes.

The roof extension would be set back from the front elevation of the dwelling and would have an angled front façade. It would add an additional storey and increase the height of [site address] , such that it would be significantly higher than the adjoining three storey townhouses, No 17 and Nos 19-22 [name]. Due to its design and set back from the frontage, the proposed roof extension would not be readily visible when viewed from the section of [name] directly adjacent to the dwelling. However, views of the roof extension would be obtainable from the access to the front of Nos 1-4 [name] and in particular, from the entrance into [name] and from [address].

Whilst the height of the roof extension would not exceed that of the adjacent four storey building, it would, nonetheless, disrupt the uniformity of the roof line of the three storey terrace and would stand out as a bulky, incongruous and unsympathetic addition which would be harmful to the character and appearance of the existing dwelling and to the architectural unity and coherence of the remainder of the terrace. Accordingly, I find that the proposal would be harmful to the character and appearance of the surrounding area due to its prominence and incongruous appearance.

The appellant has referred to other roof additions that are visible from [address], such as those within [address]. [name] agree that several dormer additions to properties in [address] are clearly visible from [address], these are seen against the original pitched roof form of the dwellings and are not directly comparable to the appeal proposal which would add significantly to the overall height of the dwelling. I therefore place little weight on these examples.

I therefore conclude that the proposal would have a harmful effect on the character and appearance of host dwelling and the surrounding area. Accordingly, the proposal would conflict with Policy D4 of the London Plan 2021 (LP), and Policies LP1 and LP2 of the London Borough of [site address] Local Plan (2018) (the Local Plan) which collectively require development to be of a high architectural and urban design quality which respects, contributes and enhances the local environmental character and local context, including through appropriate building heights. It would also be contrary to the advice contained within the Council’s Supplementary Planning Document - [name] and [name] (2015) which states that roof extensions should be in-scale with the existing structure and contrary to the design objectives of the National Planning Policy Framework (2023) (the Framework).

The site is within [name] 1, within an area of low probability of flooding from rivers and sea. The Council confirm that the site is also located within an Area Susceptible to [name], an Area for [name] and a Critical Drainage Area.

Policy D11 of the LP states that development proposals should maximise building resilience and minimise potential physical risks, including those as a result of extreme weather and flood hazards. Policy SI 13 of the LP states that amongst other matters, development proposals should aim to achieve greenfield run-off rates and to ensure that surface water run-off is managed as close to its source as possible.

Policy LP21 of the Local Plan also provides detailed guidance and states that within such areas, a drainage strategy is required for all major development. A drainage strategy is required for all other developments where there is evidence of a risk from other sources of flooding, including surface water, ground water and sewer flooding.

As the appeal proposal is for a roof extension, it would not lead to a reduction in the amount of permeable surface around the dwelling. Furthermore, I have no substantive evidence to suggest that the proposal would result in any appreciable increase in run-off compared to that associated with the existing building. I therefore conclude that there is no evidence that the proposal would give rise to an increased risk of flooding.

Accordingly, I find that the proposal would comply with policies D11 and SI 13 of the LP and Policy LP21 of the Local Plan. There would also be no conflict with the Framework insofar as it seeks to avoid inappropriate development in areas of flood risk.

[name] have not identified any harm with respect to flood risk, I have found that the proposal would have a harmful effect on the character and appearance of the existing dwelling and surrounding area.

Therefore, for the reasons given above, I conclude that the appeal should be dismissed.