Appeal 3369459

The appeal is allowed, and planning permission is granted for a single storey rear extension with a flat roof and roof lights at [site address] , Merton, Wimbledon [postcode] in accordance with the terms of the application, Ref 25/P0628, and the plans submitted with it, subject to the conditions set out in the attached schedule.

The description of development in the banner heading is taken from the application form but has been amended in the interests of clarity.

After completing my consideration of the appeal, the appellant drew my attention to a recent prior approval permission granted on site (Council Ref. 25/P2421), dated 29 September 2025, authorising an extension of a similar footprint with an eaves height of 3m. Parties were notified of that decision and given an opportunity to comment. No party has sought to rely on any aspect of the subsequent decision or raised any points of objection. I have had regard to the planning history as thus updated.

The effect of the proposed development on the living conditions of the occupiers of No. [address], with particular reference to sense of enclosure and loss of daylight.

The appeal property is a semi-detached two-storey dwelling forming part of a short run of similarly designed dwellings within a tight-knit street frontage. It is separated from No. [address] to the north by a narrow passage, which extends just beyond the broadly aligned rear elevations, with the appeal property projecting slightly beyond that of No. 5. Beyond this point, the garden boundaries step outward to form a shared boundary positioned along the centre line of the passage. The site boundary with the passage comprises a tall close-boarded fence incorporating a gated entrance and topped by a modest lattice feature. Although the fence steps down along the common boundary, it remains at a notable height.

Established boundary planting within No. 5, comprising evergreen and limited deciduous species, increases the height and effectiveness of the boundary screening, contributing to a high level of privacy and a pronounced sense of enclosure to a patio area immediately to the rear of this neighbouring property. At the time of my visit, the patio accommodated a garden table and lounge chair set, indicative of regular use. This space is framed by a rear glazed door serving a dual‐aspect through‐lounge, and the side elevation of a single‐storey kitchen extension incorporating a side glazed door and rear‐facing window. In the area beyond the patio, the boundary planting thins briefly before regaining its density and height.

As viewed from the rear patio of No. 5, the narrow separation between the dwellings, together with the existing boundary screening, would ensure that the proposed development, while discernible, would be largely filtered from view, even during the winter months when leaf coverage would be reduced. Its massing would not materially increase the sense of enclosure presently experienced within this part of the garden. For the same reasons, the amount of daylight reaching this area and the glazing to the adjoining rooms, which are served by additional sources of light, would not be materially reduced so as to result in unacceptable overshadowing.

At the point where boundary vegetation becomes less dense, the rearmost element of the proposed extension would be more perceptible and may give rise to a modest increase in enclosure and some limited overshadowing. Nonetheless, any such effects would be confined to a relatively small portion of the garden, situated beyond the principal patio area and away from the main rear-facing rooms, and which appears to be less intensively used.

I have had regard to the Council’s recent prior approval permission (ref. 25/P2421, dated 29 September 2025). There are similarities between the schemes with the appeal scheme being marginally greater in height. I have taken this into account above. Consequently, it does not alter my conclusions regarding the living conditions of neighbouring occupiers.

Taking these factors into account, I conclude that the siting and overall form of the development would not harm the living conditions of the occupiers of No.[address], with particular reference to sense of enclosure and loss of daylight. The proposal would accord with Policies D12.3 and D12.4 of the Merton Local Plan (2024) (MLP) which amongst other things, seek to ensure that new development safeguards the residential amenity of existing occupiers.

I have considered the conditions put forward by the Council against the National Planning Policy Framework (Framework) and where necessary I have amended the wording in the interests of effectiveness and precision.

In addition to the standard time condition, I have imposed conditions requiring the development to be carried out in accordance with the approved plans and with the facing materials specified in the application form, in the interests of certainty and for the avoidance of doubt.

To safeguard the living conditions of adjoining occupiers, I have also imposed a condition specifying that access to the flat roof of the development shall be for maintenance or emergency purposes only, and that it shall not be used as a roof garden or similar.

The Council have requested a condition requiring compliance with flood mitigation measures detailed in a Flood Risk Assessment (FRA) dated 28 February 2025. That document is not before me and I cannot rely on material that has not been available to all parties. However, the site lies within [name] 1, where the borough’s [name] identifies an increased potential for elevated groundwater. A site-specific FRA was submitted with the application. In order to accord with MLP policies F15.7 and F15.8 and London Plan policy SI13, it is necessary and reasonable to impose a condition to secure the implementation of flood mitigation measures.

For the reasons given above, I conclude that the proposal would accord with the development plan as a whole and the Framework, and therefore the appeal is allowed.

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: [name]-331-BR01 (Existing Location Plan/Block Plan) and CG01 (Existing and [name], Elevations and Sections).

The facing materials used in the development hereby permitted shall be those outlined in the application form.

Access to the flat roof of the development hereby permitted shall be for maintenance or emergency purposes only, and the flat roof shall not be used as a roof garden, terrace, patio or similar amenity area.

The development hereby permitted shall incorporate flood mitigation measures, the details of which shall first be submitted to and approved in writing by the local planning authority. The approved measures shall be implemented in full prior to first use of the development and shall thereafter be retained. End of Schedule