Appeal 3291739

The appeal is dismissed insofar as it relates to the alteration and extension to existing roof involving hip to gable, 3no rear and 2no front dormer windows.

The appeal is allowed insofar as it relates to the single storey rear extension, and planning permission is granted for a single storey rear extension at [site address] in accordance with the terms of the application, Ref 21/4642/HSE, dated 23 August 2021, so far as relevant to that part of the development hereby permitted and subject to the following

The proposed single storey rear extension hereby permitted shall begin not later than three [3] years from the date of this decision.

The proposed single storey rear extension shall be constructed in accordance with approved plans: • ‘Elevations as Proposed,’ [name]. LJI/21/04, • ‘Plans as Proposed,’ [name]. LJI/21/03.

The materials to be used in the external surfaces of the rear extension shall match those used in the existing building.

The roof of the extension hereby permitted shall only be used in connection with the repair and maintenance of the building and shall at no time be converted to or used as a balcony, roof garden or similar amenity or sitting out area. www.planningportal.gov.uk/planninginspectorate 1 Appeal Decision: APP/N5090/D/22/3291739

I have taken the description of the development from the Council’s Decision Notice as this provides more detail as to the specific elements requiring planning consent.

I note on the appellant’s Application Form that the Title of the appellant is given as ‘[name] with the [name] given as ‘John’ and the Surname given as ‘Barry.’ The name given in the title of the application form appears to have been made in error and the appeal form confirms the appellant’s name. I have therefore utilised the appeal form for the name of the appellant which is also confirmed on the Decision Notice.

The main issue is the effect of the roof alterations upon the character and appearance of the locality, including the setting of the Monken Hadley Conservation Area (CA).

I note correspondence from the Appellant1 with regards to the appeal site being outside the CA, as it is noted within the Planning Officer’s Report that the appeal site is within the CA. Having checked the location of the site on the [name] supplied by the Council, the side boundary of the appeal site lies along the border of the CA, however it is clear that the appeal site is outside the CA and would be considered within the setting of the CA. I have made this decision on this basis.

The appeal site lies alongside the CA boundary with Character Area 3 – Hadley Green Road West and Hadley Green Road. The significance of this area comes from the two main through routes of [address] and Hadley Green Road that converge at the [address]. The area has a semi-rural feel with expanses of open countryside with a scattering of dwellings where as one gets closer to the [address], the form and development of dwellings is more transitional. Along these two main the routes dwellings are more historic with vernacular dwellings with functional designs with many dating from the eighteenth and nineteenth centuries. The development of [address] appears much later and has the appearance of one of the first more planned residential streets to the outskirts of the settlement that marks the transition into the settlement. In this location the development begins to become more denser in layout as part of speculative developments coming off the main Hadley Green Road of the early – mid twentieth century.

Whilst the appeal site does not form part of the CA, the dwellings along [address] maintain the positive elements of the CA such as simple and functional vernacular design of dwellings; well landscaped grounds and an emphasis of spaciousness in and around dwellings which are a positive contribution to the setting of the CA. With vegetated setbacks to the road edge, setbacks to side boundaries, street trees and large rear gardens; small gaps between 1 Email to Planning Inspectorate Dated 15 February 2022 www.planningportal.gov.uk/planninginspectorate 2 Appeal Decision: APP/N5090/D/22/3291739 dwellings provide glimpses to the tops of trees and greenery beyond. The setbacks with gaps in and around dwellings with vegetated surroundings reinforce a spacious, leafy and distinctive character.

The appeal site contains a single storey dwelling with accommodation within the roof space. It is of brick construction with a hipped roof with a small front dormer window. There is a variety of building forms in the area with the majority of dwellings along East view being two storey detached and semi-detached dwellings with hipped roof forms, and opposite the road along smaller cul-de-sacs being later twentieth century development of two storey dwellings with pitched and gabled roof forms.

In undertaking extensions and alterations to existing buildings, the London Borough of Barnet Local Plan Core Strategy (CS) Policy CS5 seeks to ensure that redevelopment delivers a high quality design by respecting local context and distinctive local character, including the setting of heritage assets. The London Borough of Barnet Development Management Policies (DMP) Policy DM01 seeks to encourage development that provides positive characteristics such as understanding context, be high quality in design, form, scale, layout and the spaces around them, amongst others. Additionally, DMP Policy DM06 seeks that consideration is given to preserve and enhance the character and appearance of conservation areas, which includes their setting. These policies are supported by the Residential Design Guidance Supplementary Planning Document (RDG) which offers guidance on specific elements of designing new schemes and alterations, taking into account context and character, amongst others.

When considering roof extensions, the RDG notes that roof extensions can have large impacts upon the character within an area. Whilst the additional height of the proposed roof would not appear uncharacteristic within the street, the proposed roof extension would lift the height of the apex of the roof and elongate the apex to the rear with a large flat component where there would be a lean-to component to the front and rear which atempts to mimic a pitched and gabled roof. The proposal would also include the installation of two roof lights to both the front and rear roof planes. Whilst it is not unusual to see a pitched and gabled roof form in this context, the proposed roof form would be uncharacteristic with its large flat component to the centre of the roof. Whilst it would appear that this has been undertaken to lower the overall height of the roof, the result is a large amount of visual bulk and massing which is evident in the side elevation. [name] appreciate comments in the appellant’s Statement of Case (SoC) that the appeal site is different to the remaining dwellings in the street, the resultant design would have quite a squat form in appearance which would lack proportionality when viewed within the street scene against the more traditional and functional vernacular of the surrounding dwellings.

With regards to the dormer windows, as per the RDG, the planning of dormer windows is required in order to ensure appropriate placement, and subservience, particularly noting whether dormer windows are a characteristic of the surrounding locality. Whilst it is appreciated that the dwelling contains a small existing dormer to the front and a dormer window to the rear, dormer windows are not a characteristic element within the existing street scene. The proposal would add two dormer windows to the www.planningportal.gov.uk/planninginspectorate 3 Appeal Decision: APP/N5090/D/22/3291739 front and two dormer windows to the rear, along with a glazed section of the rear protruding gable end. The amount of dormers proposed would clutter the roof forms and elevate the status of the dwelling and could not be considered a subservient element to the proposed roof.

I note commentary in the appellant’s SoC with regards to inconsistency with decisions for ‘many adjacent properties,’ however no further details or clarifications have been provided to support these claims. Having visited the street and surrounding area, it was not evident that there were similar approvals for roof extensions or dormer windows to the extent as proposed in this appeal.

Taken as a whole, and in conclusion of this matter, in this particular circumstance, the proposed roof extension would be incongruous in this location as a result of design, massing and visual bulk, and not reflective of the positive characteristics of the character and appearance of the area. The development would cause an incongruous element within the street scene which would cause detriment to the street scene and towards the significance of the CA from development within its setting. Consequently, the proposal would be contrary to the CS Policy CS5, and [name] DM01 and DM06 as detailed previously which are supported by the RDG as described previously.

Although serious, the harm to the CA caused from development within its setting in this case would be ‘less than substantial,’ within the meaning of the term in paragraph 202 of the National Planning Policy Framework (the Framework). Paragraph 200 of the Framework states that any harm to, or loss of, the significance of a designated heritage asset requires clear and convincing justification. Paragraph 202 of the Framework requires that, where a proposal would lead to less than substantial harm, the harm should be weighed against the public benefits of the proposal.

The applicant has not outlined any public benefits of the scheme, however to me, the public benefits of the scheme would deliver larger residential accommodation for the existing dwelling, as well as result in short term employment opportunities in the construction of the extension. However, these benefits may also be present in a more appropriately designed scheme.

I therefore find that the public benefits would not outweigh the harm to the CA. The scheme therefore conflicts with the Framework, which directs, at paragraph 199, ‘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’.

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. www.planningportal.gov.uk/planninginspectorate 4 Appeal Decision: APP/N5090/D/22/3291739

The proposal includes a single storey rear extension. The extension is modest in size and design that is generally proportionate to the form and composition of the appeal building. I therefore find neutral harm in respect of this element of the proposal towards the significance of the CA from development within its setting and I note the Council raised no objection in this regard either. As the single storey rear extension is both physically and functionally severable, I consider a split decision would be a logical outcome. That said, the single storey rear extension is compliant with CS Policy CS5 and [name] DM01 and DM06.

For the reasons given above, I conclude that the appeal should succeed in relation to the single storey rear addition. However, in relation to the remaining elements, the appeal should be dismissed.

In respect of the single storey rear extension 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. I note that the Council in their suggested conditions listed the existing plans for approval, however existing plans do not require approval. A matching materials condition is required as not all details of the materials are given in the application form, and a condition limiting the use of the roof space to maintenance is necessary to avoid any potential impacts to amenity. I note that the Council has suggested a condition limiting the ability to install windows or doors on the rear extension which is for the purpose of safeguarding amenities of adjoining occupiers. No further evidence has been given in relation to this condition and I am not of the same opinion that such an installation would cause issues given it is at ground floor level. As such this suggested condition does not meet the tests of conditions and is not required.