Appeal 3326900

The appeal is dismissed.

The main issue is the effect of the proposal on the character and appearance of the host dwelling and surrounding area.

The appeal property is a detached dwelling with a prominent two storey front gable. Its roof slopes steeply on its western side with a further gable on this elevation. There is an attached garage on the other side of the dwelling which has a steeply sloping mono pitch roof.

Whilst the appeal property is of an individual design, it is located in a row comprising of relatively small-scale dwellings which are characterised by front gables or gables with a half hip, with low side eaves and steeply sloping pitched roofs. Some dwellings also have side gables or side dormer additions, although most of these are set back from the front elevation.

[address] Extensions and [name] (May 2015) (SPD) whilst non-statutory, provides useful design guidance.

The SPD states that side and rear extensions should harmonise with the original appearance of the dwelling and advises that this can be achieved by integrating the extension with the house or alternatively, by ensuring that the extension appears as an obvious addition so that the original form can still be appreciated. In such circumstances, the SPD states that the ridge of the extension should be set lower to that on the main house and that it would usually be desirable to set back the extension 1m behind the front elevation. The SPD also advises that two storey side extensions should not be greater than half the width of the original building and should be sited 1 metre from the side boundary to avoid a terracing effect occurring.

The proposed two storey side extension would not exceed half of the width of the original building when viewed from the front. It would be set back behind the front elevation by a metre and would have a slightly lower ridge height than the host dwelling. It would however be sited close to the side boundary of the site and would not comply with the guidance contained within the SPD in this respect.

I acknowledge that the existing single storey garage is also close to the side boundary, but the presence of a two storey flank wall with a high eaves would significantly close the gap between the appeal site and [address] at first floor level. In this regard, the proposed two storey extension would significantly change the scale of the dwelling on the site and would result it appearing more visually prominent and obtrusive in the street scene and at odds with the character and appearance of other dwellings in this part of the road which are more of a chalet style.

Whilst some other dwellings along Park Avenue also extend close to the side boundaries particularly at single storey level, the gaps that do exist to the side of the dwellings and above the extensions provide visual relief to the street scene. Thus, I find that the proposed extension would be harmful to the character and appearance of the host dwelling and the surrounding area in this regard.

When taken in combination with the rear extension, the proposed extensions would exceed half the width of the host dwelling. Whilst the extensions to the rear are shallow in depth, the design of the extension with a part crown roof and large gables incorporating feature windows would significantly alter the character and appearance of the dwelling such that its original form would not be readily apparent. In my view, the proposal extensions would fail to be subservient to or harmonise with the original appearance of the dwelling and would erode its original character and appearance.

I have noted the more diverse character and appearance of other parts of Park Avenue and I acknowledge that many dwellings in the road have been altered and extended. [name] have taken these examples into account, none are directly comparable to the appeal proposal which I have determined on its own merits.

Therefore, I conclude that the proposal would have a harmful effect on the character and appearance of the host property and the surrounding area. It would conflict with Policy LP1 of the London Borough of Richmond Upon Thames Local Plan (2018) which requires all development to be of a high architectural and urban design quality which respects, contributes and enhances the local environmental character. It would also conflict with the design objectives of the SPD.

For the above reasons, and having regard to all other matters raised, I conclude that the appeal should be dismissed.