Appeal 3332025

The appeal is dismissed.

A revised version of the National Planning Policy Framework (the Framework) was published on 19 December 2023, during consideration of the appeal. Having regard to the changes in the Framework and to the comparatively minor scale and nature of this appeal proposal, I consider that further consultation on this matter is not necessary.

The main issue is the effect of the proposal on living conditions at [address] next door, in terms of effects on outlook and light.

22 and [site address] are a pair of semi-detached houses. No 24 has a 3m deep single storey extension at the back. The proposal would add another 3m of depth to this, replacing the existing extension’s lean-to roof with a combined flat roof.

Policy DMHD1 of the Hillingdon Local Plan Part 2 Development Management Policies (LP2) states that in situations like this single storey rear extensions should not exceed 3.6m in depth, so that the proposed cumulative depth of 6m conflicts with the policy. The appellant suggests that policy DMHD1 is out of date because it would limit development to less than is allowed as permitted development, subject to a prior approval process1. The impact of such extensions on neighbours’ living conditions can still be assessed, however, through that process and approval can be withheld. I see no substantive conflict between the policy and the legislative regime such as to make the policy out of date as suggested. Each case must nevertheless be considered on its own merits, in light of the range of applicable policies.

No 22 has not been extended next to No 24 at the back, except for an open canopy that leaves a main rear ground floor window in the original back wall, close to the shared boundary. The proposed extension would be about 3m tall - significantly higher than the existing approximately 2m high fence dividing the back gardens. At that depth and height, it would form a substantial structure enclosing views from the rear window and looming over the adjacent garden area. It would therefore be intrusive on the outlook from the rear of No 22.

I note that the roof of the combined extension would partly be lowered due to the replacement of the existing lean-to roof. The higher part of the existing roof is, however, close to the main rear wall where views from No 22’s rear windows are screened by the canopy and would in any case be acutely angled. The existing lean-to roof therefore has little effect on No 22’s outlook at present and its partial lowering would not balance the harm caused by the introduction of a much deeper section of high wall next to the boundary.

The extension would sit to the north-west of No 22’s rear window and adjacent garden area, in a position where it would cause direct overshadowing for only a relatively small part of the day, for a relatively small part of the year. The back of No 22 would furthermore continue to receive daylight (indirect light from the sky) from a reasonably wide aspect. I therefore find no significant harm from loss of light.

The appellant refers to a 2017 appeal decision where a 6m deep single storey rear extension was allowed at another location in the Borough2. That decision was made under a different policy regime, prior to the adoption of LP2, but more importantly was for an extension which was only about 21⁄2m high on the boundary. At this lower height it should have much less impact on neighbours’ outlook despite its similar depth.

[name] find no objection in terms of light, I nevertheless conclude that the proposal would unacceptably harm neighbours’ living conditions at No 22 next door due to the effect on the outlook from that property. It conflicts with LP2 policies DMHB11 and DMHD1, which aim to ensure that development does not adversely impact on the amenity of adjacent properties, with no unacceptable loss of outlook.

I have considered all other matters raised. I recognise in particular the reasonable desire of the appellant to improve the family home, and the social and economic benefits which would flow from this - with reference to the Framework’s overarching objectives. I also note that the neighbours at No 22 have not objected, but must assess the proposal in the wider public interest, noting that others may live in that property in the future. These factors are not 1 Under Schedule 2, Part 1, Class A of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). 2 APP/R5510/W/17/3167146 sufficient to override my conclusions in respect of the main issue. For the reasons set out above, I conclude that the appeal should not succeed.