Appeal 3270817

The appeal is dismissed.

Planning permission was granted under Council Ref PA18/09549 for extensions and alterations to [site address] . This permission was granted subject to conditions, including a condition regarding the roofing slate and that agreement of the Council was required as to how the slate was to be laid.

Application PA20/08444 was an alternative proposal to the permitted scheme. The planning report for this application explains that the front and both side elevations would be unchanged from the previous approval. To the rear this revised application proposed alterations. The plans show that instead of two dormers and an inverted balcony a wider single dormer was proposed to be constructed. This application was granted planning permission by the Council. Condition 4 of this permission required the use of natural slate, a sample which is to be agreed and thereafter retained. Additionally the condition required the slates to be fixed using nails not clips.

The appellant accepts the use of natural slate and that a sample be approved. However, the substantive element of the condition which is in dispute is the requirement that the slate be nailed rather than clipped.

A revised National Planning Policy Framework (the Framework) was published on 20 July 2021. Furthermore, my attention has been drawn to the St Endellion Neighbourhood Development Plan 2020-2030 (NDP). The NDP was subject to a referendum on 15 July 2021 and the vote was in favour and therefore the NDP now carries full weight in the planning process. The main parties have been given the opportunity to make any comments on the implications of the NDP and revised Framework to this appeal and I have taken the comments into account in my considerations.

The main issue is whether the requirement in the planning condition that the slates be nailed rather than clipped is necessary and reasonable, having regard to the location within the [site address] Conservation Area (CA) and the need for decisions to preserve or enhance the character or appearance of the CA.

[site address] is a single storey building set back from the road within a residential part of [site address] . It lies in a run of individually designed, mainly detached dwellings behind boundary walls and landscaped frontages. This side of the road, including the appeal site, lies within the CA.

The [site address] Conservation Area Appraisal (June 2008) explains in detail the key components of the CA including the traditional buildings and public realm that collectively combine to produce an attractive village environment. The CA consists of a number of character areas, reflecting the expansion of the village through past centuries. This includes the harbour area and the land that steps up the steep cliff sides with an arrangement of narrow streets and vernacular buildings and which links with the area where the village expanded in the [name]. The appeal site lies within the area of [name] development and is positioned just beyond the top of the ridge on relatively more gently sloping land.

An important component of the CA, and one which contributes to its significance, is the use of natural slate for the roofs and tile hanging. The use of this material, together with the slatestone walls, provides a visually cohesive and attractive linkage throughout many parts of the CA.

The [site address] Conservation Area Management Plan (June 2008) (MP) provides guidance on the details for building works. The MP explains that the topography and development pattern of [site address] are such that the roofscape is of tremendous importance to the overall character of the place. The MP sets out a number of recommendations for roofs and this includes that new slate ought to be fixed using nails and comments that clips are usually specified to compensate for poor slate that splits when holed as using a correct lap will prevent wind lift.

In terms of the NDP, this document identifies a section of [address] as a character area. The appeal property falls within this area. Policy 6l of the NDP sets out policy objectives for the [address] Character Area and this includes that the design and layout of development within the CA should have regard to the recommendations of the MP.

The appellant has argued in the appeal submissions that the conditions attached to the original permission (PA18/09549) did not specify how the slates should be attached and makes the case that this allows them to be clipped. However, the condition includes the wording that any proposed new slate to be used in the works hereby permitted shall be laid in accordance with details which shall have first been submitted to and approved by the Local Planning Authority. It seems to me that how the slate would be laid could include whether it is nailed or clipped.

I am not aware that an application has been submitted to seek to discharge this condition. It appears, therefore, that the Council may be able to seek that any agreed tile should be nailed. Consequently, in the absence of clear details in terms of the discharge of this condition that demonstrates otherwise, I do not consider that the previous permission can be considered a fallback position regarding how the slate should be fixed and which helps support the case made in the present appeal.

The appellant has highlighted other properties in this part of [address] and elsewhere in the CA which have slates that are fixed to the roof using clips. I saw these highlighted examples at my site visit, including some more recent dwellings and the RNLI building near the harbour. I also noted that there are other sections of roofs with clipped tiles which are dotted across the area. I have taken all these roofs in to account including their effect on the character of the area, especially the situation with the buildings in [address]. However, despite these examples, roofs with slates attached by clips are the exception.

From a distance it can be difficult to discern whether a slate has been nailed or clipped. However, in closer views of clipped roofs, the extent of the slightly raised clips above the plane of the slate roof is evident. The series of raised clips, in the examples I saw, do detract, albeit to a limited extent, from what would have been an uninterrupted finish of the plane of a natural slate roof. Unclipped slate roofs are a distinctive and attractive element of the CA and the approach with the clipped slate undermines one of the features that contributes to the significance of the CA.

The recommendation to nail rather than clip the slate to the roof, as set out in the MP, has been in place for some time. It appears, because of the cases of clipped slate to roofs that have been drawn to my attention, this requirement may not have been consistently applied with all development proposals. Consistency in decision making is important. However, the evidence indicates that in the last couple of years some planning permissions have been approved with a requirement that the slate be nailed rather than clipped. While these examples of planning permissions with the nail requirement may be in the core of the CA or involve a listed building, the general principle is applicable across the CA as a whole.

The advancement of the NDP, and now its agreement at referendum, place through Policy 6l of the NDP, a direct and renewed emphasis on the need for development in the [address] Character Area to accord with the recommendations of the MP. This includes the guidance on nailing rather than clipping slates.

In the case of [site address] , the front roof slope and angled views of the south east roof of the extended building would be apparent from the road and I consider that the clips of the tiles would be evident. The rear roof slope would not be visible in wider views because of the screening effect of other buildings. Nevertheless, this part of the development would be visible from the rear garden and from within the gardens of some neighbouring properties. The significance of a conservation area does not rely solely on elements that can be seen from the public realm and therefore the appearance of the rear elevation is also important.

There would be visual benefits with the use of a natural slate for the whole roof following the removal of the old composite asbestos tiles. However, the visual appearance of the new roof would be compromised with the provision of the clipped slates and this would introduce a feature that was not locally distinctive. Indeed the provision of the roof as proposed would cause harm to the CA by the provision of a feature that would be generally uncharacteristic of one of the key features that contributes to the significance of the CA. While there may be benefits in terms of reducing wind lift with a clipped roof, I am not satisfied by the evidence that this is the only approach that could be applied to minimise this effect. In particular, the evidence does not clearly demonstrate that a nailed slate roof could not be successfully deployed in this location.

In terms of the proposal in general, the design and massing of the extensions to the building would be acceptable. However, the introduction of the clipped slate to the roof would overall produce a harmful development for the reasons explained and would adversely affect the character and appearance of the CA and thereby affect its significance as a heritage asset. The harm to the CA as a whole would be less than substantial within the meaning of paragraph 202 of the Framework. In accordance with the Framework, this harm should be weighed against the public benefits of the proposal.

The benefits of the scheme with the clipped slate roof may reduce wind lift and may make the laying of the roof more efficient and cost effective. The appellant has indicated that nailing the tiles would place an additional and unnecessary burden on the development when close neighbouring properties have not had this requirement placed upon developments. However, these benefits of the scheme at the appeal site would be largely private and therefore any public benefits merit limited weight.

The Framework advises that any harm to the significance of a designated heritage asset should require clear and convincing justification and that great weight should be given to the asset’s conservation, irrespective of the level of potential harm. I have found that the public benefits of the proposal afford limited weight and therefore would not outweigh the harm to the CA and its significance, which although minor, in accordance with the Framework, is required to be attributed great weight.

In the light of the above analysis, I conclude that the proposal to remove the requirement that the slates be nailed rather than clipped would not preserve or enhance the character or appearance of the CA. It would therefore conflict with Policy 24 of the Cornwall Local Plan Strategic Policies 2010-2030 and Policy 6l of the NDP which seek to ensure, amongst other things, that development proposals maintain the special character and appearance of Conservation Areas.

I have noted all the comments from the appellant with regard to their concerns with how the Parish Council considered and commented on the proposal. I also appreciate that they have actively worked with the Local Planning Authority and their architect to produce a design that was appropriate for the site and which subsequently received approval. However, these matters do not materially impact on the key considerations regarding the form of slate fixing and, consequently, I have based my decision on the evidence and planning merits before me.

The slate roofs of [site address] are a particular feature that contribute significantly to the CA and each property makes its individual contribution to the overall townscape. I have found that the proposed development, as a whole, with the proposal to clip the slates to the roof would harm the CA and adversely affect its significance as a heritage asset. This harm would not be outweighed by any public benefits.

It follows that the requirement set out in the planning condition that the slate be nailed rather than clipped is a reasonable and necessary requirement to make the overall development acceptable in planning terms. The requirement of the condition meets with the tests as set out in paragraph 56 of the Framework. Accordingly, I conclude that the appeal should be dismissed.