Appeal 3334729

The appeal is dismissed.

The appeal site is located in the [address]/[address] Conservation Area (the CA). I have therefore had special regard to section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act).

The main issue is whether the proposed development would preserve or enhance the character or appearance of the CA.

The CA comprises of a predominantly residential area that is primarily made up of late Georgian and early Victorian terraces. The long, elegant frontages, consistent rooflines, the use of brick and stucco and the symmetry present in the arrangement of fenestration, provides consistency to the terraces and a rhythm to the streetscene as a whole. Front elevations have typically seen little alteration ensuring that the homogeneity present within the terraces has been retained. This, alongside the architectural consistency between the terraces provides a coherent and distinctive character and appearance, present across the CA.

Pertinent to the appeal, the character and appearance and thus the significance of the CA stems from the prevalence of Georgian and Victorian terraces, their elegant frontages and the consistency in appearance across their length.

[address] consists of a row of three storey properties with a basement, which aside from modern development to either end, was constructed in 1849. With its ground floor rusticated stucco and brickwork above, ground floor arched windows and doors with fanlights and pilasters, [address] is typical of the elegant terraces that characterise the CA and is a locally listed building. The [address] has retained its consistency across the front elevation and there is little variation between individual dwellings, including to the rooflines.

The historic part of the terrace is also characterised by the rhythmic pattern of butterfly roofs to each dwelling, although the views of roofs at ground level are limited by the presence of the parapet. Views are thus restricted to the regular arrangement of chimneys, other than at 10 and [address] where alterations to the roofline have occurred through the installation of roof extensions, with projecting elements visible.

Notwithstanding the alterations at No 10 and No 11, the remaining dwellings in the historic part of the terrace, including the appeal property, [site address] , have seen little alteration to their rooflines. This is evident from ground level in that, aside from the alterations at No 10 and No 11, the only structures that extend above the height of the parapet are the consistently arranged chimney stacks. This is in contrast to the opposing terrace along [address] which backs onto the [address] properties. This terrace has seen a number of alterations to its roofline, photos of which have been provided by the appellant.

The elegant appearance of the historic part of [address] and the consistency in appearance across the terrace are contributors to its significance as a locally listed building. These elements reinforce the significance of the CA.

The proposal would result in the removal of the existing butterfly roof and the provision of an additional storey above the existing roof level, set in from the parapet. The structure would adjoin the existing chimney stack, which would be increased in height as part of the proposal. The external walls of the extension would be clad with tiles salvaged from the existing roof.

The proposal would amount to the provision of a substantial and incongruous protrusion above the roofline of the terrace, adjacent to and extending above the height of the existing chimney stack. Given the existing level of visibility of the chimney stack and, taking into account the proposed increase in height, the proposal would clearly become a prominent addition to the roof of the terrace, extending well above the parapet in views from the junction of [address] with [address], eroding the consistency of the existing roofline of the locally listed terrace.

Given its likely prominence, I am not convinced by the appellant’s assertion that any views of the proposal would be screened by the street tree to the opposite side of the road. Moreover, I cannot be certain that a street tree will remain in this position for the lifetime of the development and nevertheless, it will offer little screening when it is not in leaf. The appeal proposal would also be easily seen from neighbouring properties and from the shared spaces around [address].

For these above reasons the proposal would erode the consistency in the appearance of the existing terrace, to the detriment of its significance as a locally listed building and would fail to preserve the character and appearance of the CA as a whole.

My above reasoning is reinforced by the guidance contained within paragraph 1.150 of the Council’s Urban Design Guidelines (2017) (the UDG) which states: ‘Within conservation areas, the roofline is often an important feature contributing to the character of an area and therefore proposals for roof extensions anywhere along an unaltered roofline within a conservation area will not generally be acceptable.’ The Guidelines set out that the scope for roof extensions is dependent upon whether the unity and consistency of the roofline has already been compromised. In that regard, I acknowledge that the rooflines at No 10 and No 11 have been modified, however, the vast majority of the roofline of the terrace remains unaltered and the overwhelming character is of regular butterfly roofs set behind a parapet. Furthermore, that [address] has apartment blocks with different roof forms, built in the 1980s and 1990s adjoining both ends of the terrace, does not justify alterations to the historic section of the terrace.

Schedule 3.[address]/[address] Conservation Area Guidelines (2002) (the CAG) lists properties where roof extensions are considered to be appropriate. The appeal property is not listed within that schedule. This also reinforces my above reasoning.

I acknowledge that a significant number of alterations to the roofline have occurred to the terrace at [address]. However, evidence of existing harm to the CA is not justification for further harm, particularly as the roofline to the historic part of [address] has remained largely unaltered. Indeed, incremental changes to buildings which positively reinforce the character and appearance of a conservation area have potential to dilute and undermine an area's special interest.

The appellant references a mansard roof extension that was recently approved by the Council at [address] in 2021. As this has been constructed, I was able to view it on my site visit. I saw that this was visible in the streetscene and extended above the parapet in views from ground level. However, I have been provided with limited information relating to that approval and consequently I do not know the precise circumstances, including the presence of pre-existing development, that led to the Council concluding that the roof extension was acceptable. This limits the weight I can give to this decision. Nonetheless, whilst I accept it is close by, this roof extension is not viewed in the same context as [address] or the appeal site.

For the above reasons, I conclude that the proposal would fail to preserve or enhance the character or appearance of the CA. This would be contrary to the requirements of section 72(1) of the Act. For the same reasons it would cause harm to the significance of the CA as a designated heritage asset.

With reference to Paragraphs 207 and 208 of the National Planning Policy Framework (the Framework), in finding harm to designated heritage assets the magnitude of that harm should be assessed. Given the extent and nature of the proposals, I find that the harm to the CA and the setting of the listed building would be less than substantial. This is nonetheless, of considerable importance and weight. Under such circumstances, Paragraph 208 advises that this harm should be weighed against the public benefits of the proposal, including, where appropriate, securing the asset’s optimum viable use.

Public benefits would arise from the construction phase of the proposed extension although these would be limited by the small scale nature of the development. I acknowledge that the appellant’s children are sharing a bedroom at present and the appeal proposal would improve this situation, however this is a personal benefit rather than a public benefit. The proposal would allow existing Islington residents to continue to remain a part of the community having been present within the area for some time. Whilst the appellant argues that this is a public benefit, there is nothing before me to convince me that the appeal proposal is the only means of ensuring that the appellant remains within the community. Thus, whilst I acknowledge the greater scrutiny for new development within conservation areas, any public benefits in this regard are therefore inherently limited.

Paragraph 206 of the Framework is explicit in its requirement that any harm to the significance of designated heritage assets should require clear and convincing justification, which, in all of the respects outlined above, I find not to be the case in the appeal before me. Cumulatively, therefore, whilst I acknowledge the public benefits of the scheme referred to above, they would not outweigh the harm to the designated heritage asset to which I must give considerable importance and weight.

The proposal would fail to preserve or enhance the character and appearance of the CA. This would be contrary to the requirements of section 72(1) of the Act and the provisions within the Framework which seek to conserve and enhance heritage assets. There would also be harm to the significance of a locally listed building. The harm to heritage assets would be contrary to Policies D3, D4 and HC1 of the London Plan (2021) and Policies PLAN1, DH1 and DH2 of the Islington Local Plan Strategic and Development Management Policies (2023). Together, these seek to ensure new development constitutes high quality design that preserves and enhances heritage assets.

Conflict would also occur with the guidance contained within the CAG and the UDG as set out above.

Having considered the development plan as a whole, the approach in the Framework, and any other relevant considerations, I conclude that the appeal should be dismissed.