Appeal 3352129

The appeal is dismissed.

The main issues are the effect of the proposed development on the character and appearance of the host dwelling and area and on the living conditions of existing and future occupiers with particular reference to external space.

The appeal property is a two storey, semi-detached dwelling with a deep single storey extension to the rear. It has a short rear garden with further paved amenity space to the side. It is located in a road comprising semi-detached and terraced dwellings of a similar original design and appearance.

Policy SC7 of the London Borough of Hounslow Local Plan 2015-2030 (2015) (LP) requires development proposals to complement the original building and for extensions to have regard to the quality, character, materials and scale of the principal building, be subordinate to the existing building and not overdevelop the site in terms of mass and density. It also expects development proposals to maintain the character and amenity of private spaces (including rear gardens). Policy SC5 of the LP states that extensions should not result in undue loss of usable garden space.

The Council’s Residential Extensions Guidelines Supplementary Planning Document (2017) (SPD) whilst non-statutory, provides further useful design guidance. The SPD states that extensions should not lead to a substantial reduction in garden space/amenity space and if a property has a small garden this may restrict the size of any acceptable extension to ensure a usable open space is retained. It recommends that rear gardens are at least equal to the footprint of the original dwelling.

The proposed extension would be set back from the front elevation of the host dwelling and would not therefore be prominent in the street scene. The extension is of a chamfered design, with part of it following the alignment of the boundary fence. A distance of 1m would be retained to the side boundary. An existing shed would be demolished but the extension would fill in the majority of the usable garden space to the side of the dwelling.

The existing deep extension already takes up much of the original rear garden space of the dwelling. The proposed extension would add further floorspace and in combination with the existing extension, would result in large and disproportionate additions to the dwelling which would dominate its original form and would appear cramped and overdeveloped in relation to the plot size and the boundaries of the site. This would be harmful to the character and appearance of the host dwelling and the pattern of development in the area. Whilst other properties in [address] have also been extended or have large outbuildings, generally more space appears to have been retained around the buildings.

The proposed extension would also further reduce the amount of external space around the dwelling to a level that would conflict with the guidance set out in the SPD and the lack of usable, private outdoor space would be harmful to the living conditions of existing and future occupiers.

I acknowledge the improved internal space and the appellants comments that the garden is dominated by noise from aircraft and that their preference is for more indoor space. However, this does not justify the overdevelopment of the site and the need to ensure that the dwelling retains an appropriate amount of external space in the interests of the character of the area and the amenity of future occupants.

In conclusion, I find that the proposal would have a harmful effect on the character and appearance of the host dwelling and the area. Further harm would be caused to the living conditions of existing and future residents with regard to external space. Accordingly, the proposal fails to comply with the design and amenity objectives of Policies SC5 and SC7 of the LP and the SPD.

For the above reasons, and having regard to all other matters raised, I conclude that the appeal should be dismissed.