Appeal 3315066

The appeal is dismissed.

The main issue is whether the proposed development would preserve or enhance the character or appearance of the Canons Park Conservation Area (CA).

The CA’s significance derives from its landscaped open green character, associated with retained elements of the original Canons Park Estate, and from the Tudor revival design of many of the houses within it. [address] contains mainly 2 storey semi-detached houses with a variety of designs. Several, including the appeal property and adjoining neighbour, have design elements identified in the Canons Park Conservation Area Appraisal and [name] (2013) (CAAMP) that reflect the Tudor revival theme. They include steep pitched roof front gables with timber detailing and white painted render, 2 storey pitched roof gables at the rear and wooden front doors. The appeal property also has a tall chimney at the rear between the gable roof sections, in addition to the chimneys on the roof ridges shared with the adjoining neighbour.

The Council’s Supplementary Planning Document: [name] (2010) (SPD) advises that extensions should harmonise with the scale and architectural style of the original building and the character of the area.

The proposed development includes raising the roof at the back of the house by placing a crown section between the pitched roofs on the rear gables to provide an extra bedroom. Natural light would be provided by rooflights. The pitched roofs differ in height and the proposed crowned roof between them would be an awkward and incongruous addition, albeit its position set back between the gable roofs would obscure views of it, other than from the appellant’s rear garden. The proposed side rooflights are shown on the plans projecting out from the roof plane, rather than flush with it, and as such would be conspicuous and visible from the street. The tall rear chimney would be removed to accommodate the roof extension. As noted in the CAAMP, chimneys add character to houses and contribute greatly to the CA’s special interest. Although it is not visible from the street it can be seen from the rear and, along with the rear 2 storey gables, appears to be an original feature which contributes to the character and appearance of the house. I therefore consider its removal, in combination with the proposed roof extension and rooflights, would harm the character and appearance of the appeal property.

The proposed first floor rear extension would be acceptable in principle. However, the design of the gable loft windows would appear at odds with that of the first floor windows and would be larger and more obtrusive than the gable windows on neighbouring houses. Also, I saw no Juliet balconies on the rear of other properties close to the appeal site and this proposed addition would also appear out of place. I accept that views of the proposed development would be limited to the rear gardens of neighbouring houses and from the rear of some properties on [address] and that trees along the side and rear boundary of the host property would provide some screening. Nonetheless, the proposed development would fail to harmonise with the existing building thus harming its appearance and that of the CA.

Given the small scale of the development within the context of the Conservation Area as a whole, it would not harm its character. There would however be harm in terms of its appearance. The harm would be localised, limited and less than substantial but would nevertheless be contrary to the National Planning Policy Framework (2021) (the Framework), Policies D3 and HC1 of the London Plan (2021), Core Policy CS1 of the [name] (2012), [name] 1 and DM 7 of the Harrow Development Management Policies (2013), the SPD and the CAAMP which require high quality design that positively responds to local distinctiveness and conserves or enhances heritage assets.

Any harm to the significance of a designated heritage asset requires justification and, in accordance with paragraph 202 of the Framework, I must weigh the harm against the public benefits of the proposal. Although no public benefits have been put forward by the appellant, there would be modest benefits arising from short term employment during its construction. However, such benefits would not outweigh the harm to the appearance of the building and Canons Park Conservation Area.

I note that the side dormer was considered acceptable by the Council. However, as it would accommodate stairs up to the roof extension, which is not acceptable, I do not consider a split decision to allow this element of the proposal would be appropriate. 10.I have considered the examples of other extensions nearby provided by the appellant, but none appeared to be directly comparable with the current appeal proposal. In any case, I have come to my own view regarding the development rather than relying on the approach the Council may have taken elsewhere. 11.The appellant has referred to pre-application advice given by the Council. However, it is not bound by the advice given. In any case, procedural issues such as this must remain a matter between the main parties. More particularly, my remit is limited to assessing the planning merits and impacts of the proposed development, and I have reached my decision on this basis.