Appeal 3299099

The appeal is dismissed.

The main issues are the effect of the proposal on the character and appearance of the appeal property and the wider area, and on the living conditions of neighbouring occupiers in respect of outlook and privacy.

There is a uniformity and rhythm to the mainly semi-detached 1930’s style residential properties in and around [address]. Whilst the front elevations are the most visible from the street scene, the rear elevations are clearly visible from neighbouring properties and contribute to the character and appearance of the area.

The proposal seeks to construct a conservatory to the rear of an existing single storey rear extension. Policy DMHD1 of the Hillingdon Local Plan Part 2 - Development Management Policies (adopted January 2020) (LPP2), sets out various criteria that alterations and extensions are required to meet, including limits on the depth of rear extensions. Paragraph A1.7 of the supporting text to that Policy states that: ‘The addition of conservatories or other extensions to buildings that have already been extended will not be permitted’.

The proposed conservatory, combined with the existing extension, would result in a significant increase in the depth and footprint of the main dwelling and would be much larger than other nearby extensions. The height of the proposal, taller than the existing extension, would reinforce its scale. Both the depth and height would exceed the limits set out in LPP2 Policy DMHD1. Although a relatively lightweight structure, the proposal would be both physically and visually significant on the rear elevation, adding mass and scale to the existing extension and dwelling, resulting in an inappropriately large addition to the host dwelling. Consequently, it would not appear subordinate to the main dwelling in floor area, width, or height.

Therefore, the proposal would harm the character and appearance of the host dwelling. It would be visible from neighbouring properties and glimpsed from [address] through the gap to the side of No 70 and, due to its scale, it would alter the predominant pattern of development. Therefore, while it would not result in the loss of landscape features, it would also harm the character and appearance of the wider area.

Accordingly, it would fail to comply with LPP2 Policies DMHD1 and DMHB11 and Policy BE1 of the Hillingdon Local Plan Part 1 - Development Management Policies (adopted January 2020) (LPP1), insofar as they require development to achieve a high standard of design and improve and maintain the quality of the built environment.

The existing extension at the appeal site is a single storey, full width rear extension which abuts the boundary to the neighbouring property No 72, which has no rear projections. Despite its relatively translucent and lightweight nature, seen in combination with the existing extension the additional mass, scale, and depth of the proposed extension along the boundary would result in an overbearing impact when viewed from the downstairs habitable room of No

Consequently, the proposal would harm the outlook from that property and create an unacceptable sense of enclosure for current and future occupiers, to the detriment of their living conditions.

Furthermore, the side elevation of the proposal would be glazed along the boundary with No 72. Given the relatively low height of the boundary fence, this would result in a significant increase in overlooking into the rear amenity space and rear habitable room of that dwelling. This would result in a significant loss of privacy for the occupiers of No 72. The submitted plans do not indicate any other boundary treatment is proposed.

The appellant has suggested a condition that this elevation be obscure glazed. Whilst this may reduce the sense of overlooking during the day, due to the proximity to the boundary it would still be possible to perceive persons behind the obscured glass. In addition, when the conservatory was lit during darkness hours, it would emphasise the presence of persons in the conservatory. Therefore, such a condition would not adequately reduce the sense of overlooking.

In conclusion, the proposal would harm the living conditions of the occupiers of No 72 in respect of outlook and privacy. Accordingly, the proposal would fail to comply with LPP2 Policies DMHD1 and DMHB11 and LPP1 Policy BE1 insofar as they require development to be of a high standard of design that does not adversely impact on the amenity of adjacent properties, does not result in unacceptable loss of outlook, and promotes community cohesion.

Although the appeal property is not a heritage asset or within one, national and local policy emphasise the importance of high-quality design, which this proposal would not achieve. Therefore, the lack of a designation does not justify the harm I have identified above.

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

I have considered all the submitted evidence and the Appeal Planning Officer’s report and agree with the recommendation. On that basis the appeal is dismissed.