Appeal 3346942

The appeal is dismissed.

The main issues are the effect of the rear ground floor extension on the living conditions of neighbouring occupiers and its effect on the character and appearance of the host property and the surrounding area.

No objections are raised to the porch element of the appeal proposal and there are no reasons to disagree.

Planning permission has previously been refused for a full width 6m deep extension at the rear of the property. A revised ‘L’-shaped extension scheme, whereby the extension was reduced to 3.6m along the boundary with No [address] (No 9) was granted planning permission. The difference between the approved scheme and the appeal proposal is the addition of a glazed section in the stepped-in area. This decision thereby focuses on this ‘infill’ element of the current proposal.

The depth of the proposed extension would considerably exceed the depth permitted by the Council’s Policy DMHD 1. It would clearly breach a 45-degree line taken from the nearest neighbouring window to the boundary. I have taken into account the height of the boundary fence and the impact of the appellant’s existing, lower, conservatory. However, in my judgement, the depth of the proposed extension adjacent to the common boundary would lead to an unacceptable mass of development. The proposed extension would harm the living conditions of the occupiers of No 9 by reason of being overly dominant and visually intrusive.

The glazed element of the extension adjacent to the boundary would be translucent and lighter in form than a solid material. However, if permitted, this area could well be infilled in the future. Additionally, if blinds or curtains were to be fitted, they would, in effect, present a more solid appearance than glazing alone. It would be unreasonable to require open glazing to be retained by

I conclude that the extension would harm the living conditions of the occupiers No 9 by reason of overdominance, overshadowing, visual intrusion and loss of outlook. Consequently, the proposal is contrary to Policies BE1 of the Hillingdon Local Plan: [name] - [name] (2012), [name] 1, DMHB 11 and DMHB 12 of the Hillingdon Local Plan Part Two - Development Management Policies (2020) and Policy D3 of the London Plan (2021) which collectively seek to safeguard the living conditions of neighbouring occupiers.

Turning to design matters, the glazed element of the proposed extension would to some extent break up the appearance of its massing. However, the extension would remain a large and bulky development due to its excessive depth and size and it would dominate the existing property. Furthermore, its overall size would be uncharacteristic of other extensions in the surrounding area.

I conclude that the size, width, bulk and massing of the proposed rear extension would be a dominating and incongruous form of development that would fail to respect the form and composition of the host dwelling. It would also harm the character and appearance of the surrounding area. The proposal would therefore be contrary to the collective design objectives of Policy BE1 of the Hillingdon Local Plan: [name] - [name] (2012), [name] 1, DMHB 11 and DMHB 12 of the Hillingdon Local Plan Part Two - Development Management Policies (2020) and Policy D3 of the London Plan (2021).

For the reasons set out above and having regard to all other matters raised, the appeal is dismissed.