Appeal 6003315

The appeal is allowed and planning permission is granted for demolition of single storey shed and erection of three storey side extension at [site address] in accordance with the terms of the application, Ref 58119/APP/2025/2778, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with drawing nos ‘Location Plan’; 004; 005; 006; 007; 008; and 010.

The external materials of the extension hereby permitted shall match those used in the existing dwelling.

The description of development in the banner heading above is taken from the application form. I have removed reference to the internal layout in the description used in my main decision given that this does not form an act of development.

The main issue is the effect of the proposal on the character and appearance of the host dwelling and the surrounding area.

The appeal site comprises an end terrace property in a long row of similarly scaled dwellings. Accommodation is set over three floors albeit the dwelling takes the appearance of a two-storey property within the street scene. This is akin to the design and appearance of other properties within the terraced row. However, due to variations in material finishes, dwelling widths and building lines, overall, the terraced row does not display a strict uniformity.

The surrounding area is predominantly residential in nature, with other terraced rows of a similar design featuring within the street scene. To the south of the appeal site, separated by an area of open space, there are also larger scaled buildings with three-storey gable ends abutting the pavement.

Policy BE1 of the London Borough of Hillingdon Local Plan Part 1 (2012) (LPP1) relates to the built environment requiring new development to improve and maintain the quality of the built environment, including through achieving a high quality design in extensions which enhances the local distinctiveness of the area.

Policy DMHD 1 of the London Borough of Hillingdon Local Plan Part 2 (2020) (LPP2) relates to alterations and extensions to residential dwellings setting out various criteria which proposals will be required to meet. Included within these is a requirement for new extensions to appear subordinate to the main dwelling in their floor area, width, depth and height.

Specifically in relation to side extensions, the policy sets out amongst other matters, that side extensions should not exceed half the width of the original property. The policy also refers to two storey side extensions being set in a minimum of 1 metre from the side boundary, in order to maintain adequate visual separation and views between houses.

The proposed extension to the property would match the existing dwelling in terms of its building line and overall height. The proposal would therefore be difficult to interpret as a later extension once built. However, given the modest width and floor area of the proposal, far below half the width of the existing dwelling as required by Policy DMHD 1 of the LPP2, I find that the extension would still overall form a subordinate addition to the dwelling.

Given the above identified variations in appearance within the terraced row, the extension would assimilate well with the established built environment, without appearing overly obtrusive. In this case therefore, the lack of reduced height when compared to the main dwelling would not be visually harmful.

The proposal relates to a three-storey addition and thus the requirement of Policy DMHD 1 of the LPP2 in relation to distance to a side boundary is not strictly relevant. Even if I were to apply the same principles, given the positioning of the appeal site adjacent to the area of open space, the aims of the policy in terms of achieving adequate visual separation between houses would be easily achieved, despite the positioning of the extension adjacent to the side boundary.

Although built form would be slightly closer to the adjacent area of open space, the blank elevation facing towards the area of open space would not be materially different to the visual effects established by the side elevation of the existing dwelling. I have therefore identified no visual harm to the street scene in this respect.

Based on the above, the proposal would have an acceptable effect on the character and appearance of the host dwelling and the surrounding area. It would therefore comply with Policy BE1 of the LPP1 and Policy DMHD 1 of the LPP2. It would also comply with [name] 11 and DMHB 12 of the LPP2 which collectively require proposals to be well integrated with the surrounding area and harmonise with the local context, including by taking into account the surrounding scale of development.

Policy D4 of the London Plan (2021) (LP) sets out an overarching approach to delivering good design. Policy D3 of the LP, amongst other matters, states that development proposals should deliver buildings which positively respond to local distinctiveness, including through their layout, scale and appearance. I find no conflict with Policies D3 or D4 of the LP arising from the appeal proposal.

I shall impose a condition specifying the relevant drawings to provide certainty for all parties. A condition requiring materials to match the existing dwelling is necessary in the interests of maintaining the character and appearance of the area.

The Council has stated that no additional conditions would be required. Whilst the associated officer report refers to a tree protection condition, I do not have adequate evidence before me to suggest that this condition is necessary to make the development acceptable.

For the reasons given above, having regard to the development plan and all relevant material considerations, I conclude that the appeal should be allowed.