Appeal 6000483

The appeal is allowed, and planning permission is granted for the replacement of existing side and rear ground floor extension with new single storey side and rear extension, front bay window addition, and fenestration changes, at [site address] , [name], Twickenham [postcode] , in accordance with the terms of the application PA25/0664, subject to the conditions set out below.

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 numbers: 177-E-010, 177-E-011, 177-E-012, 177-E-013, 177-E- 014, 177-P-0201, 177-P-0221,177P-0231, 177-P-0241, 177-P-030, 177-S- 001 and 177-S0021.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The Richmond Local Plan 2024-2039, which was in draft at the time the Council refused planning permission, was formally adopted on 7 October 2025. This replaces the Richmond Local Plan (2018), such that policy LP8 of that plan and cited on the decision notice is no longer part of the development plan and has no weight. I have therefore determined the appeal having regard to the relevant policies within the Richmond Local Plan 2024-2039 (the Local Plan), with particular regard to policy 46.

The main issue is the effect of the proposal on the living conditions of the occupiers of Number [address] with particular regard to outlook.

The appeal property is a two storey end of terrace residential dwelling. It has an existing two storey rear outrigger and a further single storey rear extension. There is an outdoor patio space and a garden area which faces east. Adjacent is number [address] (No. 128), which is part of the same terrace sharing similar qualities. No. 128 has a three quarter plot width, single storey rear outrigger which contains a kitchen and a w/c. The kitchen has a moderate sized window with outlook to the southern elevation where the sink is located. The w/c window faces east, is closest to the appeal property and is frosted glazed, having little outlook. There is an east facing glazed door directly next to that which gives outlook onto the garden. The outrigger is a narrow width, and outlook is unaffected by the appeal site’s existing rear extension alongside the shared boundary.

The proposal would extend the single storey rear extension to 3.5 metres (m) and fill the full width of the plot boundary to boundary, an increase of around one metre. The eaves of the proposed development would be lower than the existing on the shared boundary with No. 128, reduced from 2.78m to 2.60m.

There would be no adverse effect to the adequate outlook from the south elevation window of No. 128. The rear glazed door would retain its long view outlook to the rear garden and remain unaffected by the development on the shared boundary. The bathroom window is frosted glazed and not a habitable room with little outlook. The reduction in height of the existing rear extension along the shared boundary would be a small benefit in terms of outlook from the garden space. This would mitigate the small increased projection of the proposal in this location. These elements, taken together, lead me to conclude that there would be a negligible impact on the living conditions of No. 128 with particular regard to enclosure.

I acknowledge that the rear extension would not fully comply with the guidance within the [name] and External Alteration Supplementary Planning Document (2015) (SPD), which finds ground floor rear extensions acceptable where not exceeding 3m in depth and that the proposal would exceed this guidance by 0.5m. Where proposals exceed this depth, the guidance suggests eaves should be reduced to 2.2m at the shared boundary. I have reasoned above that the development would not cause harm to the living conditions of No. 128, and the SPD acknowledges that the final test of acceptability would be dependent on the specific circumstances of the site. In this case, I am satisfied that the specific circumstances of the layout and context of the adjacent property provide justification to set aside the numerical requirements of the SPD.

I note that the Council assessed the w/c window of No. 128 against the ‘BRE 45° test’ and found that adequate levels of sunlight and daylight would continue to be achieved. However, such a test should not be applied to non-habitable rooms such as this space.

Consequently, the proposal would not have an adverse effect on the living conditions of the occupiers of Number [address] with particular regard to outlook.

Accordingly, the proposed development would comply with the Local Plan Policy

This seeks to ensure, among other matters, for heights, massing, and siting of new development to safeguard adequate outlooks for neighbouring occupants avoiding any undue sense of enclosure. Furthermore, the proposal would comply with the National Planning Policy Framework 2024 insofar as it seeks high standards of amenity for existing and future users.

In addition to the standard three-year period implementation condition, which is a statutory requirement, it is necessary, in the interest of certainty and precision, to define the plans with which the appeal scheme should accord.

The Council have suggested a condition requiring that a finalised set of plans be submitted and approved to confirm a consistent front elevation window design. This would be unnecessary given that the approved plans demonstrate the design and materials of windows to be constructed and that the officer’s report stated that there is no consistent window design within the street.

For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be allowed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is allowed.