Appeal 3313194

The appeal is dismissed.

The main issues are the impact of the development on:- i) the character and appearance of the host dwelling and the surrounding area; and ii) the living conditions of the occupiers of [address], with particular regard to outlook, overshadowing and overbearing impact.

The area comprises residential properties of a mixture of styles, with many having been altered and extended. The detached dwelling at No.146 benefits from existing additions including a large dormer window and a single-storey rear extension which links with the attached garage to the side.

The proposed first-floor extension would not be quite as deep as the single-storey element but would cover the full width of the dwelling and project up to the dormer. This would create a cumbersome relationship with the hips of the crown roof inset below the box dormer. The design would also be at odds with policy DMHD1 (viii) of the Hillingdon Local Plan: [name] - Development Management Policies (2020) which advises that large crown roofs will not be supported on detached houses.

Together with the existing dormer, which is a prominent feature, the design and form of the first-floor extension would result in an incongruous appearance. As a result, the rear elevation would be entirely consumed by extensions and its original identity lost.

Whilst the development would be to the rear, and visually the impact on the wider area would be limited, the development would represent a poor standard of design to the detriment of the character and appearance of the dwelling.

Accordingly, this proposal would conflict with Policy BE1 of the Hillingdon Local Plan: [name] – [name] (November 2012), policies DMHB11; DMHB12 and DMHD1 of the Hillingdon Local Plan –[name] - Development Management Policies (2020) and policies D3 and D8 of the London Plan (2021). Together these seek to ensure that developments are of a high-quality and that extensions appear subservient to the original dwelling and respect its design. Neighbour – No.148

The width of the garage separates the appeal property from the shared boundary with No.148, which also has a single-storey element adjacent. The proposal would not bring the two-storey form of the dwelling closer to the neighbour, and the main first-floor rear windows to No.148 are inset some distance from the edge of that property. As such, there would be sufficient distance to ensure that the extension would not unduly restrict outlook or have an overbearing impact.

There are also first-floor windows in the side elevation, and whilst there is no information before me to indicate what rooms they serve, they align with the flank of the appeal property, and the proposed extension would be sited to the north. I thereby do not find that the increased depth of the dwelling at the first-floor level would result in overshadowing or a material loss of outlook to be harmful to the living conditions of the occupiers of No.148.

The proposal would thereby accord with Policies DMHB11 and DMHD1 of the Hillingdon Local Plan - [name] - Development Management Policies (2020) with regards to ensuring satisfactory relationships with adjoining dwellings.

[name] have found that the development would not adversely impact the amenities of No.148, the design of the extension in combination with existing alterations would be harmful to the character and appearance of the dwelling, and conflict with the Development Plan.

Therefore, for the reasons set out the appeal is dismissed.