Appeal 3322088

The appeal is dismissed.

The main issue is the effect of the proposed development on the character and appearance of the host property and the area.

The houses on Roker Park Avenue are detached, finished in brickwork, and set back from the highway. They are of a very consistent form and design, almost all having part of their first floor set well back behind the remainder of the building’s front face, and with a tall vertical window in their side wall. Their siting, style, form and finish gives the area a locally distinctive sense of uniformity and cohesion.

The Hillingdon Local Plan Part Two: Development Management Policies was adopted in 2020 (‘the HLPP2’). HLPP2 Policy DMHD 1 provides detailed criteria on alterations and extensions to dwellings. As well as requiring extensions to respect the design of the original house, and to not adversely affect the character and appearance of the street, it sets out that two storey side extensions to detached properties should be set back a minimum of 1 metre behind the main front elevation.

The proposed extension would be sited above the host’s integral garage, where its distinctive vertical side window is located, and would be set back around 0.5 metre from the building’s front face. Consequently, although the extension would have the same ridgeline as the host, the original building’s staggered form, which is so typical of Roker Park Avenue, would be much diminished. In the streetscene, the resultant building would thus be markedly at odds with the prevailing style of houses in the road.

My attention has been drawn to a first floor side extension at [address], which I observed on my visit, and which was granted planning permission by the Council in 2017 (Ref: 24573/APP/2016/3850). That development is similar to the scheme before me, albeit it is only set back 0.3 metre from that building’s front face.

However, that development was approved before the adoption of the HLPP2, at a time when, according to that officer report, there was no policy requirement for extensions to be set back from the front wall of a detached house. Thus, whilst Councils should strive to issue consistent decisions, there has been a material change in circumstances since that one was made. That development, which appears to be unique in the road, and whose form is at odds with the other properties in it, does not provide cogent justification for the scheme before me.

Notwithstanding the proposed use of matching materials, due to its form, style and siting, the scheme would significantly harm the character and appearance of the host property and the area. It would thereby conflict with HLPP2 [name] 11 and DMHB 12, and Policy BE1 of the Hillingdon Local Plan Part One: [name] (2012).

Amongst other things, and in general terms, these require development to be designed to the highest standards, and to harmonise and integrate with its local context taking account of matters such as scale, mass, bulk, setbacks, rooflines and streetscape rhythm. Moreover, it would also conflict with the more specific stance on house extensions in HLPP2 Policy DMHD 1. Whilst this would be a first floor extension, that includes the thrust of its advice on two storey side extensions.

In its favour, the scheme would provide additional space for the occupants, and thereby optimise the site capacity, in accordance with Policy D3 of the London Plan 2021. However, it would fail to accord with its requirement for good design in Policy D4.

The scheme’s modest public benefits do not outweigh the significant harm that it would cause. Consequently, having regard to all other matters raised, the appeal is dismissed.