Appeal 6006738

The appeal is dismissed.

For clarity and brevity, I have used the description of development given on the Council’s Decision notice in the banner heading above.

The main issues are the effect of the development on: • the character and appearance of the area including the host dwelling; and • the living conditions of occupants of [address] (No 149), with regard to outlook and daylight and sunlight.

The character of the rear elevations and gardens of dwellings in [address] and the nearby surrounding area, is typified by red brick semi-detached houses with modest single-storey extensions or conservatories and flat rear dormer extensions in the roof that can be seen in the longer and roof level views. No 147 with a single storey rear extension and flat roof dormer accords with the character and appearance of the area.

Notwithstanding the glazed appearance of the proposal, its scale and mass would significantly add to the depth of the existing extension and adjoin the existing garage. As a result, in combination with the existing extension, the proposal would be a bulky addition to the host dwelling that would not be subordinate to it and would appear prominent when viewed from adjacent rear gardens and rear windows. It would also significantly exceed guidance in the London Borough of Barnet Local Plan Supplementary Planning Document Residential Design Guidance, 2016 (RDGSPD), for the length of an extension to a semi-detached house.

While the appellant contends that the proposal would read as a glass box rather than an extension to the house, the fact remains that the use and appearance of the proposal, which would include a PVC clad wall and aluminium framing, would appear as an excessive addition not only to the host dwelling.

The appeal proposal would result in harm to the character and appearance of the dwelling and the surrounding area. It is therefore contrary to Policies CDH01 and CDH05 of the London Borough of Barnet Local Plan, 2026 (the Local Plan) and D3 of the London Plan (2021) (LP). [name] require extensions to respond to, and complement, the character and appearance of the area and existing building, and to be subordinate to the dwelling. As supported by guidance in the RDGSPD that extensions should reflect the design of the original building and be consistent in scale with it to ensure they do not look too bulky and prominent.

The appeal site is one of a pair of semi-detached dwellings and adjoins No 149. No 149 has a rear conservatory and also a garage to the rear, located at the opposite side of the garden to the boundary with No 147. The existing rear extension at the appeal site extends beyond the existing conservatory at No 149.

The proposed conservatory at No [address] to the shared boundary with No 149 and extend significantly beyond the existing rear extension. The height of the conservatory would vary, sloping away from the rear of the existing extension. Adjacent to the boundary with No 149 the extension would have a PVC clad wall which would be significantly higher than the boundary fence. This would result in an overbearing outlook for occupants of 149, and a sense of enclosure given the location of the side elevation of the garage at No 149 on the opposite side of the garden. The proposal would therefore harm the outlook for occupants of No 149.

The appellant argues that the glass roof would ensure that a satisfactory level of light would be retained at No 149 while the PVC clad wall would improve privacy. However, the PVC clad wall would result not only in a loss of daylight to No 149 but also result in a loss of sunlight from increased overshadowing of a patio area at No 149. This loss of light would be harmful to the enjoyment of the garden for occupants of No 149.

Consequently, the proposal would harm the living conditions of occupants of No [address] with regard to outlook and daylight and sunlight. Therefore, the development would be contrary to Policies CDH01 and CHD05 of the Local Plan and D3 and D6 of the LP (2021). [name] require development proposals to provide a good standard of amenity and allow for acceptable levels of daylight, sunlight and outlook for adjoining occupants and maximise the usability of outside amenity space. As supported by the RDGSPD, which states that extensions should not result in a sense of enclosure or overbearing impact on adjoining properties.

For the reasons given above the appeal should be dismissed.