Appeal 6001667

The appeal is dismissed.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The description of development has been taken from the application form. The applicant was highlighted as [name] on the planning application forms. However, the appellant has been identified on the planning appeal form as [name], who previously was indicated to be the agent for the planning application. A request has been made for clarification on the apparent discrepancy, albeit that at the time of writing none had been received. I am mindful that the right of appeal is vested with the applicant for the corresponding planning application, and in the absence of any clarification as to [name] status to progress the appeal or relationship to the applicant, I have proceeded with the appeal on the basis of the identification of [name] as the original applicant.

The main issues are the effect of the proposed development on the character and appearance of the host dwelling and area, and the living conditions of the occupants of [address] with regard to outlook.

The Council and appellant agree that the rear dormer, 3 front roof lights and conversion of the roof from hip to gable are Permitted Development under the Certificate of Lawful Development (ref. 22729/APP/2025/1827) and that the single storey rear extension (ref. 22729/APP/2025/1837) has express planning permission. I have no evidence before me to conclude otherwise. Accordingly, the focus of this appeal will be with regard to the double storey side extension and the part first floor rear extension.

The predominant urban form within [address] is terraces of four dwellings. As such and given that two-storey side extensions are not a common feature, the overall bulk of dwellings appear uniform. This uniformity combined with the planned layout of dwellings contributes to a positive character and appearance.

The appeal site comprises a two-storey, semi-detached dwelling and despite being different in form, numbers 110 and 112 reflect the overall character of the area through general uniformity of design and bulk. Whilst the host has a single-storey side extension, its position within a wider plot than the adjoining property, together with its overall scale, ensures that the extension reads as a subordinate element. As a result, the original design and bulk of the host dwelling remain clearly legible and uniform within the wider context, and creates visual balance when viewed with its attached neighbour. The host dwelling therefore contributes to visual quality of the area.

The proposed development would introduce a two storey side extension set back from the front elevation at first floor and set down from the main roof ridge. It would, in relation solely to the massing of the host dwelling, appear as a subordinate addition.

However, the proposal would result in a notable increase in the overall width of the appeal dwelling causing its bulk to appear prominently larger than the surrounding dwellings within [address], including its attached neighbour. Furthermore, the introduction of the two-storey side extension would result in a dwelling departing from the prevailing design of the surrounding properties. By virtue of its erosion of uniformity, the introduction of an incongruously massed dwelling, and the visual unbalancing of the semi detached pair, the proposal would harm the character and appearance of the area.

At the front elevation, the corner of the proposed side extension would be set away from the side boundary by 1 metre, which would accord with Policy DMHD1. [name] acknowledge the boundary’s chamfer would result in this gap being reduced further down the side extension, the compact urban layout means that it would not be overly prominent and the existing spatial rhythm would be retained. Save for glimpsed views, the proposed side extension for the most part would appear suitably set back from the side boundary.

Whilst the proposed first floor rear extension would appear within a wider scheme of extensive alteration; it would in itself be a modest addition to the host dwelling. Due to its siting within a context of varying rear extensions and its inconspicuous siting not readily visible from the public realm, it would not result in harm to the character and appearance of the host dwelling or area.

Whilst the use of materials that match the host dwelling would create a sense of visual consistency, this would not mitigate the harm to the character and appearance arising for the reasons above.

For these reasons, I conclude that the proposed side extension would result in harm to the character and appearance of the host dwelling and area. I therefore find conflict with Policy BE1 of the Hillingdon Local Plan: [name] - [name] (2012), [name] 11, DMHB 12 and DMHD 1 of the Hillingdon Local Plan: Part Two- Development Management Policies (2020) ([name]), and Policies D3 and D4 of the London Plan (2021) (LP). [name], among other things, seek to ensure that development harmonises with the local context, is well integrated with and enhances the distinctiveness of the area. I further find conflict with the National Planning Policy Framework (2024) (the framework) where it seeks to achieve well-designed places.

The garden of No 114 is narrower and shorter than those of surrounding properties, with the boundary shared with the appeal site encroaching in a way that causes the garden to narrow towards its end. At present, the occupants of No 114 have an unimpeded outlook from their rear ground floor windows with outlook over the shared boundary with No 112, conditions of which would be generally preserved under the extant permissions, due to the single storey height of what has been approved.

The proposed first storey rear extension would project from the rear elevation of the host dwelling by approximately 3.3 metres. Whilst it would be set back from the boundary, its height would result in additional prominent mass within the outlook of the rear windows of No 114, with particular regard to the ground floor due to their closer proximity. This would result in a loss of outlook for the occupants of No 114, eroding the existing outlook above the boundary fence and beyond that of what the extant permissions would provide. These conditions would be made acutely worse by the configuration of dwellings and the size of No 114’s garden, which would result in the proposal appearing even more dominant.

Furthermore, the proposed first storey rear extension in cumulation with the two storey side extension would result in a dominant mass within close proximity to the boundary. The development would appear overbearing to the occupants of No 114 from their rear garden, particularly when using the area immediately to the rear of their house.

It is agreed by the parties that the proposed extension would be located outside of the 45 degree angle, which has primarily been used to assess the proposal’s impact on daylight. Whilst this may be the case, this does not preclude the proposed development’s effects of loss of outlook and overbearing impact arising from its overall bulk and siting.

The appellant contests that the Council has not provided evidence of harm to living conditions. However, I consider that the officer report is sufficiently explicit in the harm that would arise from the proposed development. In any event, matters relating to the issue of outlook largely relate to planning judgement. In my view, I concur with the Council in that the proposal would be detrimental to the levels of outlook from the rear windows that could reasonably be expected by the occupants of No 114.

The issue of light, privacy and noise and disturbance with regard to the living conditions of the occupants of No 114 are not ones contested and are not determinative matters within this appeal. Notwithstanding, light and outlook are different considerations, and, in this instance, the acceptability of the former does not preclude any harm to living conditions with regard to outlook from the rear windows of No 114.

For these reasons, I conclude that the proposed development would result in harm to the living conditions of the occupants of No 114 with regard to loss of outlook and an overbearing impact. Therefore, I find conflict with Policies DMHB11 and DMHD1 of the [name] and D3 and D6 of the LP. [name], among other things, aim to ensure that development does not result in an unacceptable loss of outlook or adverse impact to the amenity of neighbouring occupiers.

The appellant has identified a scheme which appears to relate to a new dwelling in the form of a side extension. Whilst plans have been provided, I am unable to locate the site of the development in order to consider the context in which it is located and be able to draw substantiated comparisons.

The appellant has referred to SPD 2008 section 3.2 within their statement. The related design guidance appears to broadly reflect the policies referred to above to which I have found material conflict. However, I do not have this document before me nor sufficient information in order to reasonably apply the specific document referred to. In any event, an SPD provides guidance and I nevertheless find that the proposed development would not accord with the objectives of the Development Plan as detailed above. Accordingly, I attribute this minimal weight in my

My above findings bring the proposal into conflict with the development plan, read as a whole. There are no material considerations that indicate a decision should be made other than in accordance with it. Therefore, I recommend that the appeal should be dismissed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed.