Appeal 3296219

The appeal is dismissed.

I have taken the description of the proposal from the appeal form.

The property has a lengthy planning history, which is summarised in the appellant’s statement. In particular, an appeal was allowed in 2021 for alterations to the first floor rear extension roof and the insertion of skylights (Ref: APP/N5090/D/21/3272742) (‘allowed appeal’).

The allowed appeal has not yet been built. However, this scheme differs from it insofar as it includes the addition of a rear dormer. Consequently, the Council’s decision focuses on the impact of that dormer, as does mine.

The main issue is the effect of the proposal on the character and appearance of the host property and the area, including whether it would preserve or enhance the character or appearance of the Watling Estate Conservation Area.

The National Planning Policy Framework 2021 (‘Framework’) sets out that harm to the significance of a designated heritage asset, such as a conservation area, should require clear and convincing justification. Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 states that in respect of development affecting conservation areas, special attention shall be paid to the desirability of preserving or enhancing their character or appearance.

In their requirement for development to conserve and enhance the significance of heritage assets, Policy HC1 of the London Plan 2021 (‘LP’), Policy CS5 of the [name] 2012 (‘BCS’) and Policy DM06 of the Barnet Local Plan Development Management Policies 2012 (‘BDMP’) reflect the statutory test, and are consistent with the stance in the Framework.

The site falls within the extensive Watling Estate Conservation Area (‘WECA’). Although now rather dated, the Watling Estate Conservation Area Character [name] 2007, sets out that the area was largely developed in the late 1920’s, along ‘Garden City’ principles, with buildings of different styles, usually set back from the road behind gardens, and including semi-detached houses and short terraces.

The short terraces that typify this part of [address] have a fairly simple two storey form, and largely unaltered roofs, which mostly terminate with a hip. That appearance largely continues to the rear, particularly above ground floor level, where I observed that the dwellings retain a fairly uniform style and proportions. These attributes, along with the siting and layout of the properties, give the area a locally distinctive appearance and a pleasing sense of uniformity and cohesion.

In that context, the host property, with its end and rear gables has a rather different form. However, in the allowed appeal the Inspector found that as a result of the proposed alteration of the rear gable to a hip, that scheme would not appear significantly out of place.

I observed no nearby dormers on this part of [address]. Having regard to cumulative impacts, this proposed flat roofed dormer, which would link to the proposed hipped roof extension to the rear, would give the host property an overly complex appearance. That would jar with the simple style and form of the remainder of this terrace, and of others nearby. Although the rear dormer would not be visible from the highway, and it would be hidden in some private views by the rear extension, the harm it would cause would be apparent from some nearby rear gardens.

I note that rear dormers were granted planning permission in the WECA at [address] (‘No 107’) and at [address] (‘No 115’), as well as at [address] (‘No 1’). However, the dormer at No 107 is on a large corner building whose style and proportions differ from this terraced property. Although the example at No [address], neither that property, nor No 1, also has a two storey rear projection similar to that proposed here. Those examples do not change my conclusions regarding the harm that this scheme, considered as a whole, would cause.

For the above reasons, the scheme would fail to preserve or enhance the character and appearance of the WECA. It would thus conflict with LP Policy HC1, BCS Policy CS5 and BDMP Policy DM06.

As it would not be of a high design standard, or respect the local context in terms of appearance, scale and design, the scheme would also conflict with BCS Policy CS1 and BDMP Policy DM01, and with the stance in the Barnet Residential Design Guidance Supplementary Planning Document 2016 that extensions should be consistent with the form, scale and architectural style of the original building.

In accordance with the Framework, the harm to this designated heritage asset is a matter to which I attribute great weight. However, as the harm would be less than substantial, I am required to weigh it against the public benefits of the proposal.

In this case, whilst the proposal would provide additional living accommodation for this growing family and for future occupants, the harm that the scheme would cause would not be outweighed by its very modest public benefits. In the absence of clear and convincing justification for that harm, I conclude that as well as conflicting with the development plan, the scheme would also conflict with the Framework, and does not benefit from its presumption in favour of sustainable development.

Consequently, and having regard to all other matters raised, the appeal is dismissed.