Appeal 3332697

The appeal is allowed and planning permission is granted for double hip to gable rear dormer loft conversion, installation of front roof lights and chimney removal at [site address] in accordance with the terms of the application Ref. 23/2210/HOT dated 10 August 2023, and the plans submitted with it and subject to the conditions listed below.

The development hereby permitted shall begin before the expiration of three years from the date of this permission.

The materials to be used in the construction of the external surfaces of the development hereby permitted (including fenestration) shall match those used in the existing building or otherwise be in accordance with those shown on the approved plans.

The development hereby permitted shall be carried out in accordance with the following approved plans: LR_23_14TROWLOCKAVE_00; LR_23_14TROWLOCKAVE_03 Rev.A; LR_23_14TROWLOCKAVE_04 Rev.A; LR_23_14TROWLOCKAVE_05 Rev.A.

The Fire Strategy prepared by Studio 136 Architects and received on 10 August 2023 shall be adopted on completion of the development hereby permitted and retained thereafter.

Prior to the commencement of the development hereby permitted, a Flood Risk Assessment and [name] shall be submitted to and approved in writing by the Local Planning Authority. These shall include an assessment of the impact of the development hereby permitted on flood risk to the site, details of necessary floodproofing measures to mitigate the risk, and details of any [name] required as a result of the development in order to achieve greenfield run-off rates surface water discharge or if greenfield run-off rates are not feasible, to achieve at least 50% attenuation of any surface water runoff at peak times based on the levels existing prior to the development hereby permitted.

Whilst the Council revised the description of development, I have adopted the description used in the original application.

A revised version of the National Planning Policy Framework (Framework) was published in December 2023, after the appeal was lodged. Even so, the relevant design and flooding policies of the Framework remain unchanged, albeit some of the paragraph numbering is different.

The main issues are; (a) the effect of the proposed development on the character and appearance of the host property and surrounding area, and (b) whether the proposed development would increase the potential for flood risk on the site or in the locality.

The Council have referred to policy D4 of The London Plan (March 2021) (TLP) and policy LP1 of the Richmond Local Plan (July 2018) (RLP). These policies seek, amongst other requirements, to ensure that new development is of a high quality design and demonstrates its compatibility with local character and its relationship to existing townscape and development patterns, as well as in relation to, amongst others, the scale, height, massing, proportions, form, materials and detailing of the host and surrounding properties.

A broadly similar approach is set out in paragraph 135 (previously paragraph

of the Framework, but it also states that being sympathetic to local character should not prevent or discourage appropriate innovation or change. The National Design Guide (NDG) (January 2021) reinforces the Framework, for example, at paragraph 44 by emphasising that well designed places do not need to copy their surroundings and that it is appropriate for new development to include innovation and change to reflect how we live today.

The Council have also referred to its [name] & External Alterations Supplementary Planning Document (May 2015) (SPD). Although this SPD predates both the Framework and the NDG, paragraph 8.1.1 states that hip to gable extensions will not be encouraged particularly where the existing roofscape and space between buildings are important features of the character of the area, and there is symmetry with the adjoining semi-detached property or withing the terrace where the building is located. For dormers, it states that: these should not be located on the front elevation or project above the main ridge line: they should not dominate the roof and should leave a significant area of the roof below the new dormer and either side of it; that two smaller dormers might be preferable to one larger dormer; that materials and window detailing should match existing; and that a hipped or gabled roof to the dormer may be preferable to a flat roof.

Dealing firstly with the proposed dormer on the rear elevation of the host property, whilst this would result in an increase in the bulk and massing of the main rear roof (as proposed to be extended), this increase would, in my view , be modest and would not be harmful to the host or to the streetscene. [name] observed on site, a number of properties in the area have been extended at roof level on the rear, with there being examples of large rear dormers, gabled extensions as well as other forms of extensions with flat roofs and vertical sides, either tile hung or rendered. The most prominent example of the latter is on [address] (No.12) immediately south west of the appeal site. Within that context, the proposed rear dormer would not result in any harm to the character and appearance of the host or to the surrounding area.

The proposed rear dormer would be sympathetic to the existing design of the host property (as extended), with roof tiles and other detailing to match existing. It would also integrate well with the proposed gabled design of the main roof, without being visually intrusive. It would also incorporate a number of the design principles set out in the SPD, in that it would sit below the ridge and above the eaves, as well as being set in from the sides of the main roof (as proposed to be extended). Materials and other detailing would match that on the existing rear elevation to the host. I am also satisfied that the use of a flat roof and one single dormer would be acceptable and preferable in this case, given the proposed gabled extensions to the main roof and the varied character of the roof extensions within the surrounding area. I accept that the proposal would be visible from [address] to the rear, but those views would be limited by distance and by existing boundary enclosures, planting and trees.

Turning to the proposed hip to gable extensions, I accept that there would be a material change to the appearance of the front elevation to the main roof, but, even so, the proposed gables would, in my view, integrate well with the design of and be proportional to the host property. They would also be in-keeping with similar extensions on surrounding properties and specifically its neighbours No.12 and [address] (to the north east of the appeal site). In relation to other guidance in the SPD, as the host is detached reasonable gaps would be retained between it and its neighbours and there would be no issue of “symmetry”. Also, the roofscapes of a number of properties in the area have already been extended in a similar manner, which are part of its local context.

The proposed gable extensions would include 3 new low profile Velux windows on the front elevation and there are a number of properties in the street where chimneys either appear to have been removed or were not incorporated into the original design, and as such the loss of the chimney would not harm the character and appearance of the host or streetscene. Overall, I am satisfied that the impact of the proposed gables on the streetscene would be modest, that the proposed extensions would sit reasonably comfortably on the appeal site and would not be out of keeping with similar extensions on other properties in the street.

Reference has been made to the poor quality of some of the roof extensions in the street, which either appear to have been approved by the Council or built under permitted development. Even so, I agree with the Appellant that a number of these are not directly comparable to the appeal proposal in that they include a higher roof height, different side profiles, a wider front façade, appear bulkier when viewed in the context of other rear/side dormers and include flat roofs. [name] observed on site, there are other examples of gable extensions in the street which are of a much higher quality in terms of their appearance and are of a more traditional design with a narrow ridgeline and no increase in the overall roof height, which would be replicated in the appeal proposal.

Accordingly, I find that the appeal proposal would not result in any harm to the character and appearance of the host property or the surrounding area and would thus be broadly in accord with the guidance in the SPD and compliant with the aims and objectives of policy D4 of TLP and policy LP1 of the RLP, as well as the corresponding policies of the Framework.

Policy D11 of TLP seeks to ensure that new development minimises the risks associated with, amongst other matters, extreme weather, flooding and related hazards. Policy LP21 of the RLP requires all development in [name] 3 to be supported by a Flood Risk Assessment (FRA), so as to prevent and mitigate for the flood risk from new development, with those assessments prepared in line with the policies in the Framework. Paragraph 173 of the Framework (previously paragraph 167) states that local planning authorities should, ensure, when determining any planning applications, that flood risk is not increased elsewhere and that where appropriate new development should be accompanied by a site specific FRA. Paragraph 174 (previously paragraph 168) continues by stating that some minor development should not be subject to the sequential or exception tests but should still meet the requirements for site specific FRA’s as set out in footnote 59.

The appeal site is located within [name] 3 and as no FRA has been submitted the Council contend that it has not been demonstrated that the proposed development would adopt suitable mitigation measures to prevent the flooding and drainage problems identified at the site. The Appellant contends that an FRA is not required as the proposal would not add to the existing footprint of the property or impact on ground floor level or the existing garden, and consequently it would not impact on existing drainage and water run-off. As such, the Appellant contends there would be no increased flood risk from the development, but they also state that if its decided that an FRA is required that this is a matter that can be controlled by condition.

I have noted the comment of the Appellant and also the fact that the Council’s Delegated Report does not appear to indicate that any advice has been sought on the flooding or drainage issue from relevant consultees. I have also had regard to the advice in the Planning Practice Guidance chapter on Flood risk & coastal change, where paragraph 51 states that minor development is unlikely to raise significant flood risk issues unless: it would have an adverse effect on a watercourse, floodplain or its flood defences; it would impede access to flood defence and management facilities; or cumulatively with other development it would have a significant effect on local flood storage capacity or flood flows. I have not been provided with any evidence to suggest that the appeal proposal is likely to raise any of these issues. Even so, paragraph 51 continues by stating that even applications for minor development, involving extensions or additions, should be subject to an FRA, with a shorter, simpler assessment that, as a minimum, shows that the development would be safe for its users for the intended lifetime of the development, without increasing flood risk elsewhere, and be sufficiently flood resistant and resilient to the level and nature of the flood risk.

Given the above, I am satisfied that an FRA is required to support the appeal proposal and that this is a requirement that can be controlled by an appropriate condition, requiring a site specific and proportional FRA to be submitted and approved by the Council before work commences on site.

I have considered the Council’s suggested conditions against the advice in the Framework and the Planning Practice Guidance chapter on the Use of planning conditions. Conditions requiring materials to match existing or otherwise be in accord with those shown on the approved plans and for compliance with the approved plans, are necessary and reasonable to secure a high-quality development. I also consider that a condition requiring the adoption of the submitted [name] is also necessary to ensure the fire safety of the development.

[name] have also found above, I am satisfied that a condition requiring the submission and approval of an FRA is necessary and reasonable to ensure that any flooding or drainage issues that arise from the proposed development are addressed and if required, mitigated. In this respect, I have adopted, with some minor rewording, the condition suggested by the Council.

For the reasons given above and having taken all the matters raised into account, I conclude that the appeal should be allowed.