Appeal 6000291

The appeal is allowed and planning permission is granted for ground floor rear extension, internal reconfiguration, introduction of new rooflights to the front elevation and alterations to the existing fenestration at [site address] in accordance with the terms of the application, Ref PA25/0471, subject to the conditions in the attached schedule.

Following the submission of the appeal, the Richmond upon Thames Local Plan (LP) was adopted in October 2025. The parties were given the opportunity to comment on the change in policy context and where those comments have been received, they have been taken into account.

The appeal property is situated within the Cole Park Road Conservation Area (CA). Accordingly, I have a statutory duty under Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 to ensure special attention shall be paid to the desirability of preserving or enhancing the character or appearance of that area.

The main issue relevant to this appeal is the effect of the proposal on the host dwelling and linked to this whether the proposal would preserve or enhance the character or appearance of the CA.

The appeal property is a large dwelling designed by [name]. Roe. The Cole Park Road Conservation Area No.78 Appraisal (Appraisal) identifies key features of this, and other Roe-designed properties include gambrel roofs resembling enlarged Dutch barns with gables facing the street. These dwellings are constructed of red brick with mock Tudor timber boarding and pebbledash render to the upper floors. They retain original timber window frames and glazing, some of which is stained at ground floor level. The half-timber boarding, chimneys and decorative timberwork are features that are common in many of the dwellings in the CA and contribute to a consistent streetscape character.

The CA is characterised by large-scale dwellings set within spacious plots, with generous planted front gardens and visible rear garden vegetation through gaps between buildings. Street trees and landscaped gardens contribute to the verdant character and special interest of the area. The large-scale and high-quality detailing of the dwellings, combined with the spatial hierarchy and glimpses of greenery, positively contribute to the CA’s significance.

The appeal property is a Building of [name] whose design, materials, and siting align with the positive features identified in the Appraisal and forms part of a distinctive and cohesive group of buildings. A modest gap is retained between it and neighbouring houses. There is a garage next to the house and based on the submitted information the rear extension that extends out from this was a later addition, and the rear extension would be replaced by the proposed scheme. Although the existing extension wraps around the side of the house, its single-storey scale ensures the visual gap between buildings is maintained.

The proposed flat-roofed rear extension would span the full width of the dwelling and extend partly beyond its central element. While positioned behind the garage, it would be partly visible above the garage’s hipped roof. Despite this, due the extension’s limited depth and single-storey scale it would remain subordinate to the host dwelling, avoiding dominance or disproportionate impact within the street scene. The proposal would only marginally exceed the size of the existing extension, and any encroachment into the gap between properties would be minor. Accordingly, the extension would retain the visual gap between properties and respect the established building line and preserve the spatial hierarchy that characterises the CA.

The replacement of non-original ground floor windows to the rear with full height glazed units would not harm features of importance to the CA or the host dwelling. While the existing extension’s hipped roof uses similar tiles to the main house, the proposed flat roof would reduce its overall height, ensuring that key features such as mock Tudor detailing and pebbledash above ground floor level remain prominent. Taking into consideration the pattern of development and given that these glazed windows and doors would be located at ground floor level to the rear of the property the effect of such areas of glazing would be very limited and for the reasons set out above would not harm the important features of the host dwelling. The proposed render would generally align with materials used in the host dwelling and others within the CA.

Although part of the flat roof and zinc fascia would be visible above the garage, this element would be set back and not prominent within the street. The green roof would positively complement views of vegetated rear gardens, an important characteristic of the CA. Overall, the extension’s location to the rear and its replacement of an existing structure would ensure that the high-quality design features of the host dwelling remain dominant, preserving its contribution to the CA’s significance.

The proposed enlarged first-floor rear bathroom window would match the scale and design of existing windows, avoiding harm to the dwelling’s character. Similarly, the limited number and size of rooflights, subject to a condition requiring conservation-style fittings, would prevent clutter and maintain the integrity of the roof form. As they are not proposed within the gambrel roof, they would not affect a key positive feature of the building. Similarly, the proposed front and garage doors would fit within the existing form of the host dwelling and would not detract from the important features of it. Consequently, the replacement of those doors would not harm the character or appearance of the building.

Whilst elements of the extension and in particular the flat roof and use of zinc fascia would not necessarily harmonise with the host dwelling; the [name] and External Alterations Supplementary Planning Document (SPD) supports extensions that are made to appear as an obvious addition. The proposal due to its form and materials would clearly be so and thus would be consistent with the advice in the SPD. By confining the extension to the side and rear and replacing an existing structure, the proposal would avoid harm to the principal elevation and preserve the high-quality design features that contribute to the significance of the CA and the character and appearance of the Building of [name]. Additionally, due to its scale and siting it would not affect the street trees and landscaped front gardens that positively contribute to the character of the area. The above matters and the retention of the gap between buildings and respect for the established pattern of development would ensure that the character and appearance of the CA and the host dwelling would be preserved. Furthermore, scheme would ensure the distinctive and cohesive design of the Roe designed houses would be preserved.

Therefore, for the reasons given above, the proposal would not harm the character or appearance of the host dwelling and would preserve the character and appearance of the Cole Park Road Conservation Area, as a whole. Accordingly, it would comply with Policies 28, 29 and 30 of the LP. These seek, amongst other matters, to ensure design, layout and materials respect and respond to the historic environment and any relevant heritage assets.

Further to the statutory commencement condition, a condition requiring the development to be carried out in accordance with the permitted plans is necessary in the interests of certainty. A condition requiring the materials used are in accordance with those shown on the permitted plans and details of the biodiverse roof are approved is necessary in the interests of preserving the character and appearance of the CA.

A condition requiring that the proposed first-floor bathroom window has limited openings and is installed with obscured glass is necessary in the interests of the living conditions of the occupiers of the building and neighbouring residents.

In light of the conclusions of the Flood Risk Assessment a condition requiring the development is carried out in accordance with the sustainable drainage scheme would be necessary in the interests of ensuring the proposal would not increase the risk of flooding elsewhere. I have revised the wording of this condition to require the development is carried out in accordance with it rather than require confirmation that it has been as that would be unnecessary.

A condition requiring the development is carried out in accordance with the [name] is necessary in the interests of fire safety as per Policy D12 of the London Plan.

A condition restricting the use of the flat roof is not necessary given that a balcony is not proposed and balconies often require planning permission as they do not fall under permitted development rights.

The proposed development would be in accordance with the development plan, and the material considerations do not indicate that the appeal should be determined other than in accordance with it. Therefore, for the reasons given above, I conclude that the appeal should be allowed.

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: 001; 015; 016; 020C; 030; 040; and 041.

The external surfaces of the development hereby permitted shall be constructed in the materials shown on drawing no. 020C and shall be retained as such thereafter.

Prior to the commencement of relevant superstructure works, full details of the biodiverse roof shall be submitted to and approved in writing by the local planning authority. The biodiverse roof shall be implemented in accordance with the approved details and planted/seeded with the agreed mix of species within the first planting season following the practical completion of the building works.

The extension hereby permitted shall not be occupied until the sustainable drainage scheme for the extension has been completed in accordance with the Flood Risk Assessment, prepared by STM Environmental, dated 26 February 2025. The sustainable drainage scheme shall be managed and maintained as such thereafter.

The first-floor bathroom window in the rear elevation of the development hereby permitted shall at no time be openable or glazed, otherwise than in obscured glass, below a minimum height of 1.7 metres above the relevant floor level.

The front elevation rooflights hereby permitted shall be black framed, conservation type and shall sit flush within the roofline.

The development hereby permitted shall be carried out in accordance with [name] 040 and 041 and retained as such thereafter. End of Schedule