Appeal 3356270

The appeal is dismissed.

The main issues are: • the effect of the proposed development on the living conditions of the occupiers of Nos 20 and [address], with particular reference to light and outlook; and • the effect of the proposed development on the character and appearance of the host dwelling and the surrounding area.

The appeal property is a two storey, end of terrace dwelling located in row of dwellings of a similar design and appearance. The dwelling has an existing single storey rear extension of about 3m in depth.

The proposed proposal would result in a single storey extension projecting 6m beyond the original two storey rear wall of the dwelling. My attention has been drawn to the planning history of the site and in particular to a prior approval application for a 6m deep extension. This application was refused by the Council but was subsequently allowed on appeal1 with prior approval deemed to be granted under Article 3(1) and Schedule 2, Part 1, Class A, of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) (GPDO). 1 Appeal Ref. APP/F5540/D/24/3341428

The proposed single storey extension would result in a ground floor of the same dimensions overall as the single storey extension allowed on appeal. The Council’s Residential Extensions Guidelines Supplementary Planning Document (2017) (SPD) advises that single storey rear extensions to terraced dwellings should not normally exceed 3.05m in depth to avoid loss of outlook and daylight to neighbouring dwellings. Notwithstanding this, such guidance does not constitute a rigid set of rules to be applied exclusively when other material considerations indicate that an exception may be appropriate. Furthermore, the SPD guidance does not reflect the permissible dimensions for extensions set out the GDPO.

The non-adjoining neighbour at [address] has a part two storey rear extension close to the boundary with the appeal property. Whilst the proposed single storey extension would extend beyond the rear elevation No 24, owing to its low height and flat roof design, it would not result in any significant harm to the living conditions of the occupiers of No 24. Furthermore, the first-floor rear extension would not project significantly beyond the existing extension to No 24 and accordingly, would not result in material harm to the neighbouring occupiers living conditions in terms of loss of outlook or light. Whilst the Council raise concern about a ground floor wc window on the flank elevation of the proposed extension, no adverse overlooking would occur from this window due to the existing boundary treatment.

The adjoining dwelling, [address] has not been extended to the rear. To the west of No 20, [address] has a single storey extension on the boundary with No 20. [name] 20 benefits from a generous rear garden and a relatively open aspect to the rear. Whilst the proposed single storey extension would be slightly higher than the existing extension to the rear of the appeal property, I concur with the previous appeal Inspector, that due to its height and flat roof design, the additional single storey projection along the shared boundary would not result in a significant loss of light or outlook to the occupiers of No 20.

The proposed first floor extension would have a flat roof design and would sit at eaves height. However, notwithstanding its flat roof design, owing to the 3m depth of the proposed first floor extension and its positioning on the boundary with No 20, the two-storey flank wall would be visually imposing and overbearing when viewed from the ground floor of No 20 and the part of the garden closest to the dwelling. Moreover, the extension would be on the eastern side of No 20 and, in the absence of any substantive evidence to the contrary, due to its depth and positioning on the boundary, it would be likely to result in a reduction in natural light and sunlight to the ground floor windows of No 20, at certain times of the day. The combination of loss of outlook and loss of light would have a harmful effect on the living conditions of the occupiers of No 20.

Therefore, the proposal would be contrary to Policies CC2 and SC7 of the London Borough of Hounslow Local Plan 2015-2030 (2015) (LP) which together and amongst other matters, seek to minimise harm to neighbouring residents by avoiding an unacceptable loss of daylight/sunlight, outlook or by creating an unacceptable sense of enclosure. It would also be contrary to the SPD which advises that the depth of a first floor extension should not project more than 2.5m beyond the rear wall of the house.

Policies CC1 and CC2 of the LP expect proposals to respond to the context and character of the area in terms of design. Policy SC7 of the 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. Guidance within the SPD advises that first floor extensions should be proportionate and subordinate to the dimensions of the main house and that the width of a first-floor rear extension should be no greater than half the width of the original house.

The proposed single storey extension would represent a sizeable addition to the dwelling but having regard to its low, flat roof design it would be proportionate and subordinate to the host dwelling and would not significantly detract from its original character and appearance. Moreover, the proposed extension would extend to the same depth as the 6m deep extension allowed on appeal.

The flat roof design of the proposed first floor extension would help to reduce its scale and bulk. I also acknowledge that it would be similar in design to the two storey flat roof extension to the rear of [address] although that extension only extends across part of the width of the dwelling. The proposed extension would extend across the full width of the appeal property and this, in combination with its depth of 3m, would result in an overly dominant, bulky addition.

I find that the proposed first floor extension by virtue of its width and depth would fail to be subordinate to or well-integrated with the host dwelling. Accordingly, the proposal would overwhelm and detract from the original character and appearance of the dwelling. Whilst the extension would not be readily visible from any public vantage points, it would, nonetheless, be a highly dominant addition which would detract from the character and appearance of the existing rear garden environment.

I therefore conclude that the proposed first floor extension would have a harmful effect on the character and appearance of the host dwelling and surrounding area. Consequently, it would fail to comply with the design objectives of Policies CC1, CC2 and SC7 of the LP and the SPD.

I acknowledge that the proposed extensions would be beneficial to the appellant and would improve the family’s living space and living conditions. However, this consideration does not outweigh the harm that I have identified above.

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