Appeal 3310195

The appeal is dismissed in so far as it relates to the demolition and replacement of the existing rear dormers. The appeal is allowed and planning permission is granted in so far as it relates to the addition of a new front dormer at [site address] , Kew, Richmond [postcode] in accordance with the terms of the application, Ref 22/1964/HOT, dated 20 June 2022, subject to the following conditions:

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: 23-ENDL.RD/DSGN.21, 22, 23, 24, 25, 26, 27, in so far as they relate to the works approved.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the existing building.

The main issues are the effect of the proposal on the character and appearance of the host property and whether it would preserve or enhance the character or appearance of the Kew Green Conservation Area (KGCA).

The appeal property is a 2-storey detached house that has been extended to the rear and includes accommodation within the roof. It has been designated by the Council as a Building of [name] and forms part of a group of handsome, detached houses of similar age and appearance that make a positive contribution to the character and appearance of the KGCA.

The property includes a pair of dormers within the rear roof slope that were added following a grant of planning permission in 2007. These dormers feature decorative barge boards and relate well to the scale, proportions and materials of the host property. There is also a pair of dormers within the rear roof slope of the next-door property, [address]. These are larger than the pair on the appeal property and less appropriate in terms of their design and detailing.

The proposal would include the removal of the rear dormers and their replacement with wider dormers of similar design and materials to the existing. The gap between the dormers would be narrow, to the extent that the decorative barge boards would almost touch. The width of the dormers, together with the negligible spacing between them would result in an incongruous and overly dominant form of development that would be at odds with the proportions and scale of the house property and the appearance of neighbouring houses. This would be exacerbated by the width and proportions of the windows within the dormers, which would be at odds with the size and predominately vertical emphasis of those in the original rear elevation below.

I conclude therefore that, due to their size, siting and fenestration, the proposed dormers would have an unacceptable effect on the appearance of the host property and would fail to preserve the character and appearance of the KGCA. As such, this aspect of the proposal fails to accord with Policies LP1, LP3 and LP4 of the London Borough of Richmond Upon Thames Local Plan (2018) which, amongst other matters, seek to maintain or enhance the high architectural and urban design quality which contributes to the character and heritage of the area. There is also conflict with the [address] Extensions and External Alterations Supplementary Planning Document (2015), which states that dormers should not dominate the original roof and windows within dormers should be smaller than those on the floor below.

Whilst the proposal would fail to preserve the character and appearance of the KGCA, the harm to this heritage asset would be less than substantial. In these circumstances Paragraph 202 of the National Planning Policy Framework (2021) requires me to weigh the harm against the public benefits of the proposal. I note that the proposal would provide better quality accommodation for the occupiers, which would be a private benefit only. There is nothing before me to demonstrate that improved thermal performance can only be achieved by the form of development proposed and, therefore, I attribute limited weight to this benefit. These matters do not amount to public benefits that outweigh the unacceptable harm identified above.

The proposal also includes the installation of a dormer within the front roof slope and the formation of a pair of small windows in a flank elevation. The front dormer would be of a high quality of design reflecting the appearance of the front gable and other front dormers in the vicinity. The proposed windows in the flank elevation would largely be screened by the next door house and therefore represent an inconsequential alteration. These aspects of the proposal therefore preserve the appearance of the host property and the KGCA and accord with the aforementioned policies. As they are functionally and physically severable from the rear dormers a split decision can be issued allowing these elements.

I have considered the conditions suggested by the Council having regard to the National Planning Policy Framework and Planning Practice Guidance. In addition to the standard time limit condition, I consider a materials condition is required to safeguard the character and appearance of the area. Furthermore, for the avoidance of doubt and in the interests of proper planning, a condition requiring the approved development to be carried out in accordance with the approved drawings is imposed.

For the reasons set out above, and having regard to all other matters raised, I conclude that the appeal should fail in respect of the proposed dormers in the rear roofslope and succeed in respect of the front dormer and flank elevation windows.