Appeal 3325849

The appeal is dismissed.

The main issue is the effect of the proposal on the character and appearance of the host property and its surroundings.

The host property is a detached property sited in a predominantly residential area. The property’s roof has recently been modified following the grant of permission. I also noted a flat roof extension to the rear, and a large outbuilding in the garden – seemingly a remnant of the former use of the property for social welfare purposes. It appears from the recent grant of a certificate of lawfulness that the intention is to demolish the outbuilding, which would be replaced with another sited towards the garden’s rear boundary.

The development would be comprised of what I would regard as sizeable extensions at ground and first floor levels and significant alterations to the roof. The useable floorspace within the extended building would be substantially increased. At roof level, two large, imposing gables would be introduced at the rear, each with a Juliette balcony. The gables would be linked by a flat roofed inset, intended, I presume, to provide an evenly spread headroom for the space created below – a proposed cinema room.

The appellant says that ‘the roof profile of the extension has been sensitively designed to reflect the character and overall architectural appearance of the dwelling with which it seeks to harmonise’. I do not share that view. I regard the overall design as functional, clumsy and unattractive. The scale of the extensions would appear as wholly disproportionate to the host property, and the roof would appear top heavy. Far from harmonizing with the overall architectural appearance of the dwelling, the extensions would harmfully transform it into an unattractive and overdeveloped structure. As the appellant contends, some of the houses in the appeal site’s vicinity have been subject to change and modification at their rears, but none, as far as I could see, to the extent as proposed in this case.

I acknowledge that most of the changes proposed would not be particularly discernible from the street outside. However, the extensions, particularly the modifications to the roof, would be seen clearly as sizeable, prominent and unattractive additions from adjoining gardens and from the publicly accessible spaces to the west and rear of the site, including allotments and a park.

I conclude that the proposal does not comply with many of DMP1 policy DMHD 1’s detailed design criteria and would result in harm to the character and appearance of the host property and its surroundings. Moreover, the proposal conflicts with those provisions of policy BE1 of the Hillingdon Local Plan: Part 1 [name] and those provisions of DMP policies DMHB 11 and DMHD 1 directed in combination to ensure that house extensions are well designed and reflect local character.

The Framework2 provides that good design is a key aspect of sustainable development, and that development that is not well designed should be refused. I intend to follow that guidance in this case.

All other matters raised in the representations have been taken into account, including the objection raised by a neighbouring resident. References to other development plan policies are noted, but those to which I have referred are considered the most relevant to this case. No other matter is of such strength or significance as to outweigh the considerations that led me to my