Appeal 3369627

The appeal is dismissed.

The Council’s decision notice listed four reasons for refusal, however reasons no1 and no2 are duplicates, as are reasons no3 and no4; the former are essentially concerned with matters of design, whereas the latter are concerned with the effect of the proposal upon neighbouring residential amenities. I have determined the appeal on this basis.

I therefore consider that the main issues are the effect of the appeal proposal upon the character and appearance of the area; and upon the living conditions of the occupants of 59 and [address], with specific reference to outlook.

The appeal dwelling comprises a semi-detached house that has benefitted from a hip to gable loft conversion and construction of a substantial box dormer on its rear roof slope. Prior to this occurring, planning permission was granted (4456/APP/2021/2135) for the erection of a single storey side/rear extension and part two storey, part single storey rear extension which wasn’t implemented. There currently exists a single storey rear flat roof extension and an outhouse which would be demolished to make way for the appeal proposal.

The aforementioned 2021 planning permission permitted a first floor rear extension to be constructed to a depth of 3.6m and a flat roof ground floor element adjacent to no63 of the same depth. The first floor extension as proposed before me has been reduced very marginally by 2cm. However, the ground floor element, which would also project beyond the rear elevation of the proposed first floor extension, would have a total depth of some 6m. Policy DMHD1 of the Hillingdon Local Plan: [name] – Development Management Policies (2020) (DMP) stipulates that single storey rear extensions on semi-detached houses with a plot width of more than 5m should not exceed a depth of 3.6m. Consequently, the single storey element of the proposal is in clear conflict with the development plan.

When combined with the other extensions that have already been constructed, along with the proposed first floor rear extension, the scheme as a whole would fail to appear subordinate to the host dwelling. Consequently, I cannot agree that the proposed extensions would respect and enhance the existing property’s scale, proportions and overall character; and in coming to this view I have had regard to the examples cited by the appellant, however, ultimately each case must be assessed on its own merits.

It is quite clear that the Council found in recent years the principle of a first floor rear extension to be acceptable and whilst I acknowledge that that was not within the context of the hip-to-gable conversion and box dormer which have since been constructed, I consider that it would be relatively modest in its appearance and would not overly detract from the overall character of the host dwelling. However, I find that by virtue of the depth of the single storey rear extension, that the proposal would fail to appear as a subordinate addition to the host property and would significantly unbalance the pair of semi-detached dwellings of which it forms part, with consequent detrimental effects upon the character and appearance of the area.

Therefore, in addition to conflicting with DMP Policy DMHD 1 referred to above, I also find that the proposal conflicts with DMP Policy DMHB 11 which requires all development, including extensions, to be designed to the highest standards, to harmonise with the local context by taking into account, amongst other things, scale of development; and considering the height, mass and bulk of adjacent structures, along with architectural composition.

No63 has not been extended and this property has windows to its rear elevation overlooking a patio area. The proposal would give rise to the demolition of the existing single storey rear extension of the host dwelling and that of the outbuilding to the rear. The current single storey extension is set off from the shared boundary and therefore built form would be brought closer to the neighbouring residential property by virtue of the fact that the single storey extension would be built along it. However, having regard to the demolition of the outhouse, which loosely gives rise to built form currently projecting approximately 9m along the shared boundary, on balance, I consider that the proposed extension would not be unduly overbearing upon the occupants of no 63.

I note that the Council has previously considered the approximate depth of the first floor extension to be acceptable, with there being no demonstrable harm caused to the occupants of no59 by it. However, the scheme would see a further 2.9m high flat roof extension projecting beyond that by approximately 2.4m. Admittedly, this would be set in from the boundary by 1.6m, but bearing in mind that this neighbouring property has a habitable room window and a conservatory to its rear, facing the appeal site, I consider that in totality the proposal would be unduly overbearing upon the occupants of that property. I acknowledge that no objections were raised during the consultation process, however I find, on balance, that the proposal would have a harmful effect upon the outlook of the occupants of no59 and, again, I find the proposal conflicts with [name] 1 and DMHD 11 which together require a satisfactory relationship with adjacent dwellings to be achieved, ensuring that there is no unacceptable loss of outlook to neighbouring occupiers.

Having regard to the above and all other matters raised, I conclude that the appeal be dismissed.