Part rear double storey extension, additional roof solar panels, extension to basement and external wall covering to insulated. ’ Decision

1 Appeal Decision Site visit made on 15 April 2024 by J Somers BSocSci (Planning) MA (HEC) MRTPI IHBC an Inspector appointed by the Secretary of State Decision date: 23 April 2024 Appeal Ref: APP/K2230/D/24/3337362 109 Darnley Road, Gravesend, Kent DA11 0SH • The appeal is made under Section 78 of the Town and Country Planning Act 1990 against a refusal to grant planning permission. • The appeal is made by Matt Lenton-Magor against the decision of the Gravesham Borough Council. • The application Ref 20230561, dated 25 May 2023, was refused by notice dated 4 January 2024. • The development proposed is described as ‘Part rear double storey extension, additional roof solar panels, extension to basement and external wall covering to insulated. ’ Decision 1. The appeal is dismissed insofar as it relates to the external insulation and render, solar panels installed on the roof, and front basement extension. 2. The appeal is allowed insofar as it relates to the rear basement and rear ground floor extension and planning permission is granted for a rear basement and rear ground floor extension at 109 Darnley Road, Gravesend, Kent DA11 0SH in accordance with the terms of the application Ref 20230561, dated 25 May 2023 so far as relevant to the part of the development hereby permitted and subject to the following conditions: 1) The ground floor rear extension and rear basement extension hereby permitted shall begin not later than three [3] years from the date of this decision. 2) The rear basement extension and ground floor rear extension shall be constructed in accordance with approved plans: • ‘Proposed 3D 1,’ Drawing Number P9; • ‘Ground Floor,’ Drawing Number P2; • ‘First Floor,’ Drawing Number P3; • ‘Elevations Rear,’ Drawing Number P6; • ‘Elevations Left Side,’ Drawing Number P8; • ‘Elevations Right Side,’ Drawing Number P7; • ‘Roof,’ Drawing Number P13; • ‘Basement Floor,’ Drawing Number P1; Continued next page. Appeal Decision: APP/K2230/D/24/3337362 2 3) The materials to be used in the external surfaces of the rear extension shall match those used in the existing building. Preliminary Matters 3. The Council’s decision notice contains three reasons for refusal which all revolve around the same issue of character and appearance and the resultant effect on the Conservation Area. As such, I shall deal with each of the three reasons for refusal under the one matter. 4. The Council in their Planning Officer Report state that the proposed rear basement and ground floor extension would be appropriate and in accordance with the Development Plan policies. I have no reason to dispute this opinion and given that these elements are both functionally and physically severable from the other elements of this application, a split decision is considered a suitable outcome. Given the only matters in dispute refer to the solar panels, application of external insulation and render and front basement extension; these elements will be the focus of this letter. Main Issue 5. The main issue is the effect of the front basement extension, solar panels and external render and insulation upon the existing building with special regard given to the preservation or enhancement of the character and appearance of the Darnley Road Conservation Area (CA). Reasons 6. Section 72(1) of the Planning Listed Buildings and Conservation Areas Act 1990 (PLBCA) seeks that in relation to CA’s that special attention is paid to the desirability of preserving or enhancing the character or appearance of the CA. In undertaking development, the Gravesham Local Plan First Review (LPFR) 2014 Saved Policy TC3 and Gravesham Core Strategy (CS) Policy CS20 relates specifically to CAs and the historic environment and seeks that proposals will be expected to make a positive contribution to the CA and contain sufficient detail to assess the impact of proposed development. Additionally, CS Policy CS19 is a design led policy which seeks consideration of local context, materials, design and detailing, and having good design policy, amongst others. 7. The CA’s significance is highlighted in the Darnley Road CA Appraisal, where relevant components of the significance in relation to the appeal site relate to the development of formally laid out speculative housing development as part of the suburban expansion of Gravesend during the first half of the nineteenth century. The dwellings themselves have an elevated status with paired villas and short terraces. Whilst the appeal site is three storeys, it forms part of a group of 3 pairs of semi-detached dwellings of four bays wide, with central protruding bays, shallow hipped rooves with large coaxial chimney stacks with facades being clad in stucco, although over time some of the cladding appears to be in concrete. The use of traditional materials such as timber, brick and slate along with the similar designs reinforce a uniformity and authenticity which creates a formal picturesque townscape along with vegetated front gardens which give a leafy and distinctive character. To the rear the leafy character continues with well vegetated rear gardens, the tops of trees which are visible through gaps between dwellings. The collection of historic buildings Appeal Decision: APP/K2230/D/24/3337362 3 of traditional construction and how they are experienced, which includes the appeal site, provides a positive contribution to the area. These elements reinforce the local character, appearance and distinctiveness of the area. 8. The CA Appraisal also notes negative aspects of the CA such as modern infill, garages to the rear of Darnley Road, loss of front gardens which have been converted to hardstanding, and loss of architectural details, amongst others. 9. The appeal dwelling forms half of one of the characteristic pairs of semi- detached dwellings along Darnley Road which appears to date from the early to mid-nineteenth century. Whilst the Appellant’s Statement of Case (SoC) notes that the Conservation Area Map notes that the neighbouring No.107 is not a positive building whereas the appeal building is a positive building, I do not find this the case as both 107-109 Danley Road are noted as positive buildings in the CA Appraisal.1 The building is three storeys tall with a shallow hipped roof with flat roof side component that has a parapet with flat roof that sits under the eaves of the hipped roof, with large centrally placed coaxial chimney stack to the centre of the roof. According to the appeal documents the property appears to have been re-rendered in cement from the original lime stucco construction and is showing signs of cracking and failure. The neighbouring half of the pair of semi-detached buildings appears to have been converted into flats and has render with ashlar detailing rather than the smooth stucco appearance of many of the buildings in the street. The front and rear gardens of the appeal dwelling are well vegetated and reinforce the leafy and positive characteristics of the street scene. 10. Beginning with the front basement extension, the basement would further protrude into the front garden. There appears to be some inconsistencies with this proposal given that the plans show that the roof of the basement including rooflight would extend into the front garden and remove a proportion of soft landscaping. The Appellant’s SoC mentions that there is the intention to re- establish any soft-vegetation loss in the front of the property, however there is no landscaping plan which supports these comments and the referred to photo with purple line in Appendix 7 also does not support the re-establishing of planting to the roof of the front basement extension. 11. It is made clear in the CA Appraisal that one of the negative attributes of the CA is the loss of positive characteristics, such as the turning of front gardens to hardscaping, which would appear to be what is proposed in this application. Whilst there would be some front garden retained, the hardstanding combined with the rooflight which protrudes further into the front garden would increase the clutter and built form to the front garden area which is uncharacteristic to this particular location. As such the proposal would fail to preserve or enhance the character and appearance of the CA and would therefore be contrary to LPFR Policy TC3 and CS Policies CS19 and CS20 as described previously. 12. Reason for refusal 2 relates to the installation of solar panels to each of the three roof planes and behind the parapet of the flat rooved section to the side. For all types of alterations, they need to be subservient and reflect the existing context and preserve or enhance the character and appearance of the CA. The proposal for solar panels would appear to have been developed in isolation from the significance of the CA and the surrounding context given that the roof 1 Darnley Road Conservation Area Townscape Appraisal Map, Page 29 Appeal Decision: APP/K2230/D/24/3337362 4 planes would be completely covered, obscuring important architectural detailing such as the roof of the dwelling. 13. I agree with the Appellant’s SoC that the reduction of panels, utilising different panels and experimenting with orientation could relieve some of the harm caused to the character and appearance of the CA, however as currently proposed, the increased clutter and configuration of the panels would dominate the roof planes and be detrimental to the character and appearance of the CA. 14. I note commentary with regards to Nos 161 and 104 Darnley Road having solar panels, however the Council has provided further information that the panels on No 161 do not benefit from planning consent, and those on No.104 also were installed without consent and have subsequently been granted a Lawful Development Certificate. As such these elements do not represent a precedent and do not justify the appropriateness of the proposed solar panels. As such the proposal would fail to preserve or enhance the character and appearance of the CA and would therefore be contrary to LPFR Policy TC3 and CS Policies CS19 and CS20 as described previously. 15. Turning to the third reason which involves the removal of existing concrete render and the installation of insulative render where motivations for this appear to have arisen due to the current cement render cracking. There are no details provided of the ‘rigid insulation’ or render, where LPFR Saved Policy TC3 and CS Policy CS20 require sufficient information in order to assess impact (if any) of the proposal. Considerations are needed with regards to the thickness of the insulation and render as this type of external insulation is typically a brick width thick and could mean that architectural detailing such as sills would need to be extended to accommodate this increased depth of the insulation/render, however this has not been explained. There are also considerations around the increased depth and its resultant appearance particularly where the render meets the dividing wall of the neighbouring dwelling where protruding render would be very noticeable and set forward of the wall of the neighbouring dwelling and the additional thickness of the sills which would need to be extended. These elements would appear inauthentic and detrimental to the building’s architectural integrity and authenticity. 16. Additionally, where a dwelling is erected with traditional construction techniques, this makes the dwelling ‘breathable’ in that the walls and draughts in the dwelling play an important role in the movement of moisture in, around, and out of the dwelling. The application of impervious materials such as rigid insulation and concrete render would create a barrier to the movement of moisture whereby moisture will likely build up between the brickwork and insulation material, causing likely further decay and harm to the brickwork and failure of the render, as would appear to be currently occurring with moisture buildup behind the cement render likely causing the failure of it which has further repercussions to the character and appearance of the CA. Whilst I appreciate comments in the Appellant’s SoC that the neighbouring half of the pair of semi-detached dwellings has undertaken some poor alterations such as the external staircase and garages to the rear which has a detrimental impact upon the significance of the CA, this does not provide justification to cause additional harm to the existing building via the proposed installation of insulation and render. Appeal Decision: APP/K2230/D/24/3337362 5 17. I also agree with the Appellant that there are environmental benefits that come with external insulation. Whilst this may be the case, the proposal is not the only way of achieving thermal efficiency to the dwelling and there may be other ways of improving the thermal efficiency of the dwelling without having a harmful effect towards the building or the significance of the CA. 18. Overall, there has not been sufficient information provided in order to justify the proposed insulation and render. As such the proposal would fail to preserve or enhance the character and appearance of the CA and would therefore be contrary to LPFR Policy TC3 and CS Policies CS19 and CS20 as described previously. 19. Although serious, the harm to the significance of the CA would both be ‘less than substantial,’ within the meaning of the term in paragraph 208 of the Framework. Paragraph 206 states that any harm to, or loss of, the significance of a designated heritage asset should require clear and convincing justification. Paragraph 208 requires that, where development would lead to less than substantial harm, the harm should be weighed against the public benefits of the proposal. 20. The applicant has stated that some of the elements of the development would provide environmental benefits in terms of thermal insulation and generation of green energy which are important policy objectives. Additionally, the scheme would also provide short term employment opportunities in the installation and construction of the elements of the application. However, these benefits may also be present in a more appropriately designed scheme. That said, these benefits would not justify the harm I have identified. I therefore find that the public benefits would not outweigh the harm caused to the significance of the CA. The scheme therefore conflicts with the Framework, which directs, at paragraph 205, ‘that great weight should be given to the asset’s conservation … irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to their significance’. 21. In conclusion on this matter, I consider the proposed development would cause less than substantial harm to the significance of the CA. It has not been shown that public benefits would outweigh this harm and so the proposal would conflict with the development plan. Conclusions and Conditions 22. For the reasons given above, I conclude that the appeal should succeed in relation to the rear ground floor and basement extension. However, in relation to the front basement extension, solar panels and installation of insulation and render, the appeal should be dismissed. 23. In respect of the rear extensions, it is necessary to have the standard conditions of the standard time limit for the avoidance of doubt; and the extension to be constructed in accordance with the approved plans is also necessary as this provides certainty to the scheme which has been approved. A matching materials condition is required in order to be appropriate to the existing building and the character and appearance of the locality. J Somers INSPECTOR