Appeal 3334786

The appeal is dismissed.

There are three main issues. Firstly, the effect of the proposed outbuilding on the character and appearance of the appeal site and the surrounding area; secondly, the effect of the proposed basement on the surrounding area with respect to land stability, flooding and drainage; and thirdly, the effect of the proposed outbuilding on trees.

The appeal dwelling is a traditional end of terrace house on a generous plot in a residential area characterised by similar properties. Outbuildings are common in the area, some of which are large. At the time of my site visit a significant excavation had been dug at the site of the proposed outbuilding.

The proposed outbuilding would be large with a footprint of some 9m x 8m. It would have a basement of a similar size. However, the roof would be flat and have a maximum height of some 2.5m. The building would be located at the far end of the generous garden at the appeal site, adjacent to a large outbuilding in the garden to the rear and to a modest outbuilding in the garden of No 34. It would be separated from the rear of dwellings in [address] by a former rear vehicular access which now appears to be in private ownership, although not shown within the appeal site or as being owned by the appellant.

Overall, its low profile, visual separation from the appeal dwelling and other gardens and limited visibility in the wider area would mean that, notwithstanding its size, it had no materially detrimental effect on the character or appearance of the appeal site or the surrounding area. Moreover, whilst larger than other outbuildings nearby it would remain of domestic scale and not materially out of character with its domestic setting. The Council raises concerns that the footprint of the outbuilding would be almost 80% that of the dwelling. However, the dwelling is a two storey house that at the time of my site visit was undergoing a loft extension. I therefore consider that the outbuilding at the end of the large plot would appear clearly subordinate to the dwelling. I accept that the basement would approximately double its volume but since this would not be visible it would have no material effect on character or appearance.

It is concluded on the first main issue that the proposed outbuilding would have no materially detrimental effect on the character or appearance of the appeal site or the surrounding area. In consequence, it would comply with Policies LP26 and LP30 of the Redbridge Local Plan 2015-2030 (LP), adopted 2018, and the Council’s Housing Design Supplementary Planning Document (SPD), 2019. Taken together and amongst other things these expect domestic outbuildings to be of a high quality design which respects the local character of the area, maintins the appearance of the locality and is well integrated having regard to and respect for the surrouniding area. In particular, outbuildings should be located towards the end of the garden, have eaves heights of no more than 3m for flat roofs, should be subordinate to the footprint of the original dwelling and rear garden and of a scale that has regard to the prevailing character of outbuildings in the area.

Turning to the effect of the proposed basement, LP Policy LP31 states that basement and subterranean development involving further excavation of land at domestic properties will only be supported when, amongst other things, the development includes a Basement Impact Assessment (BIA) that assesses geotechnical, structural engineering and hydrological impacts, does not threaten mature trees through changes to the hydrological conditions or the severance of tree roots and includes a sustainable urban drainage scheme.

At the time of my site visit it was clear that the large excavation over the footprint of the proposed outbuilding was close to the boundary with No 36 and that land slippage had occurred. Part of the fence between the two sites was missing. In addition, the excavation came close to a large tree in the garden of No 36.

Although an initial brief report was submitted with the application this does not address land stability or the effect on trees and consideration of drainage and flooding is rudimentary. No sustainable urban drainage scheme has been submitted. 10.I therefore agree with the Council that there is insufficient evidence upon which to assess the effects of the proposed basement. It is therefore not possible to determine whether the proposed development would have a materially detrimental effect on the stability of adjoining land, drainage or flooding in the area or on mature trees. In consequence, a precautionary approach is necessary and the appeal should be dismissed. 2 11.It is concluded on the second and third main issues that there is insufficient evidence to find that the proposed development would not have a materially harmful effect on the surrounding area with respect to land stability, flooding and drainage and trees. In consequence it has not been demonstrated that there would be no conflict with [name] LP31, LP21, LP38 and LP26 or with Policy G7 of the London Plan, 2021. Taken together and amongst other things these seek to ensure that subterranean development is of a high quality such that it does not result in ground instability, an increase in flood risk or impact on drainage or a detrimental effect on mature trees. 12.Notwithstanding my findings with regard to character and appearance which would not alter or outweigh my conclusions on the second and third main issues, f or the reasons set out above, and having regard to the representations of a third party, I conclude that the appeal should be dismissed.