Appeal 3340008

The appeal is dismissed.

As part of their appeal submissions the appellant submitted an additional drawing No 04 [name] which provides a red dashed outline of the proposal in comparison to the scheme the subject of an extant planning permission, 21/3392/HOT. Bearing in mind that no revisions to the actual design of the proposal have been advanced and this drawing simply provides a comparison between the two schemes, I consider that no parties would be prejudiced by me accepting it.

A revised version of the National Planning Policy Framework (the ‘Framework’) was published in December 2023, but there are no material changes relevant to the substance of the appeal. I have determined the appeal on this basis.

As highlighted above, planning permission was granted in December 2021 for a first floor side extension with internal alterations to [site address] .

The second condition on the decision notice required the development to be carried out in accordance with the approved plans, as listed in the banner heading above.

The Section 73 application, the subject of this appeal sought minor material amendments to the approved scheme which, amongst other things, included an increase in width of the first floor side extension by 52 cm; an increase in height of the approximate rear two thirds of the extension by 40 cm; and the provision of 3no dormer windows to the side elevation in lieu of rooflights.

Consequently, the main issue is the effect of the appeal proposal upon the character and appearance of the host dwelling, cited as a Building of [name] (BTM) and whether the scheme would preserve or enhance the character or appearance of the Broom Water Conservation Area.

The appeal site is located within a high quality residential street, predominantly comprising gable fronted and hipped roof two and a half storey houses of a relatively square floor plan.

The Broom Water Conservation Area Statement 28 highlights that these detached houses include single storey garages to the side which afford important gaps between them and that architecturally, whilst individual in character, the dwellings are unified by their rich use of materials and detailing to which I concur.

Planning permission already exists for a small first floor gable roof extension to be provided, to be connected to the flank elevation of the host dwelling by a leaded link. The ridgeline of this extension would be broadly in line with that of the garage roof in front and would be quite simple in its appearance.

In contrast, whilst the increase in width of 52 cm is not a significant figure in itself, nonetheless the front gable would no longer be aligned with the ridgeline of the garage roof and it would push built form further to the north eastern side which would reduce the visual gap between the host dwelling and that of 12 [name]. Furthermore, the increase in height of the rear approximate two thirds of the extension over the previous proposal would give it a disjointed appearance and erode the simplicity of it. I note the reference to the height of the rear part of the proposed side extension being very similar to that at 4 [name], however ultimately each case must be assessed on its own merits.

I cannot agree that the proposed extension profile would affect the existing roof line in a positive manner with it accentuating the current, slightly awkward, juxtaposition of the garage structure with the utility and kitchen addition that exist behind, albeit at a higher and therefore more noticeable level. Whilst the side extension would appear reasonably subordinate to the main house in terms of its scale, nonetheless it would be of an incongruous design, and one that would be a retrograde step from the previous planning permission.

With regard to the 3no dormers proposed to replace the previously approved rooflights, they would give rise to more visual clutter and again further erode the space between no10 and no12. I acknowledge that it is not uncommon for dormer windows to be provided on side elevations of dwellings within the Conservation Area, and whilst I note those to be found at nos 11, 13, 19, 27, 31 and 35 it is not for me to comment on the appropriateness of these or otherwise, and they do not constitute a determining factor in this appeal.

It may be that every property displays a degree of architectural uniqueness, although ultimately they do form part of a coherent whole with a clear emphasis on verticality and in many cases filling the complete width of their respective plots at ground floor level. However, the proposal would distract the eye through the creation of an uncomfortable visual duality (by virtue of the offset of the front gable) and would not only erode the architectural quality of a BTM, but also fail to preserve the character and appearance of the Conservation Area due to its erosion of the visual gap between it and the adjacent neighbouring house at first floor level.

In terms of window detailing, had I been so minded as to have allowed the appeal, a condition could have been imposed that required larger scale drawings to be submitted prior to installation. In addition the use of lead to the linking element on the extant permission would provide a contemporary foil to the more traditional architecture of the building, but nonetheless, details of external facing materials could also have been conditioned had the appeal ended in a positive outcome for the appellant.

The Council have not explained how the proposal conflicts with the [name] and Alterations Supplementary Planning Document, however, overall I find that less than substantial harm would be caused to the Designated Heritage Asset and no public benefits have been advanced that outweigh this harm.

I find the scheme contrary to Policies LP1, LP3 and LP4 of the London Borough of Richmond upon Thames Local Plan July 2018 which together require all development to be of high architectural and urban design quality, ensuring, amongst other things, compatibility with local character including the relationship to existing townscape, development patterns, local grain and frontages; as well as requiring development to conserve, and where possible, take opportunities to make a positive contribution to the historic environment of the Borough, including seeking to preserve, and where possible, enhance the significance, character and setting of non-designated and designated heritage assets.

I therefore find that the proposed minor material amendments to the extant planning permission are not acceptable, and I do not permit the variation of the wording of planning condition U0115306 imposed upon planning permission 21/3392/HOT.

Having regard to the above and all other matters raised by the appellant, I hereby dismiss the appeal.