Appeal 3292028

The appeal is dismissed.

The main issues are the effect of the proposed development on: • the character and appearance of the host property and the area; and • adjacent occupiers’ living conditions with particular regard to the outlook from [address].

The Council’s Residential Extension Guidelines Supplementary Planning Document 2017 (‘SPD’) sets out that, whilst applications will be considered on their merits with regard to the particular circumstances, in order to remain secondary to the original building, a single storey rear extension to a semi-detached dwelling should not exceed 3.65 metres in depth. Its height should be subservient to the host and should be below any first floor windows, and it should be designed to minimise harm to neighbouring properties.

The host is a hipped roofed, semi-detached property, finished primarily in brick and render, and which is the last in a row of broadly similar style dwellings on this side of [address]. On its side facing the adjacent bungalow, it has a rather discordant two storey flat roofed extension.

The proposed extension’s roof would be set well down compared to the host property, but the scheme would span the host’s rear face, including its side extension. That, together with its depth which, according to the appellant would be 6 metres and thus easily in excess of the advice in the SPD, and which would be not much less than the depth of the host, would give it a considerable bulk. Consequently, it would not appear fully subordinate to the host property.

Additionally, whilst its ‘butterfly’ roof would be an imaginative design, given this extended property’s current form, cumulatively it would result in a very eclectic appearance, which would be at odds with the generally much simpler style of nearby properties.

As it would be located to the rear, the proposed extension would not be visible in the [address] streetscene, but it would be glimpsed above the rear boundary from [address], and it would be seen from nearby dwellings. As it would also be faced in brickwork to match that on the host’s front elevation, and given its limited public visibility, it would cause only limited harm.

Nevertheless, as it would harm the character and appearance of the host property and the area, it would conflict with Hounslow Local Plan 2015 to 2030 (2015) (‘HLP’) Policies CC1, CC2 and SC7. Amongst other things and in broad terms, these require development to respond to an area’s character, with extensions which complement, and are subordinate to, the original building, and which harmonise with adjoining properties and the streetscene.

It would also conflict with the stance in the National Planning Policy Framework 2021 (‘Framework’) that development should be well designed taking into account supplementary planning documents.

The attached property at No 15 has a conservatory adjacent to the boundary with No 17. The conservatory has a masonry side wall and an outlook principally down that property’s long rear garden.

However, given its considerable depth, the proposed extension would project well beyond the conservatory. According to the Council’s calculations, its side walls, which would abut the plot’s boundaries, would be approximately 3.15 metres high. Given its siting, its considerable height and length, and its solid masonry construction, the side wall abutting No 15 would have a significant overbearing impact on those occupiers’ outlook from their conservatory and from that section of the garden immediately adjacent.

Whilst the current occupants of No 15 did not object to the scheme, I am mindful of the Framework’s stance that development should ensure a high standard of amenity for existing and future users. The scheme would conflict with that approach, and with those parts of [name] CC2 and SC7 which expect development to provide an adequate outlook and to minimise harm to neighbours as a result of matters such as an overbearing sense of enclosure. It would also conflict with the SPD.

However, as HLP Policy CC1 primarily addresses matters relating to design and character, it is of limited relevance on this issue.

In its favour, the scheme would provide additional accommodation, which would enable the appellant’s large family to live together.

In summary, the proposed development would cause limited harm to the character and appearance of the host property and the area, and it would have a harmful impact on the living conditions at [address]. [name] have considered the appellant’s personal circumstances, they do not outweigh the totality of the harm that the scheme would cause.

The proposal would conflict with the development plan when considered as a whole, and for those reasons, having regard to all other matters raised, the appeal is dismissed.