Appeal 3297381

The appeal is allowed and planning permission is granted for a rear first floor extension above existing kitchen and internal modifications and improvements at ground floor and first floor including one window (GF) and new door (FF) at [site address] , Mortlake, London, [postcode] in accordance with the terms of the application, Ref 21/4355/FUL, dated 20 December 2021, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: Site location plan; 01; 02; 03; 1090A; 1110A; 1120A; 1130A; 1140A; 1150A and 1160A.

The materials to be used in the external finishes of the development hereby permitted shall match those used in the existing building except where otherwise submitted in the original planning application.

The development hereby permitted shall not be carried out other than in accordance with the principles and methodology as described within the submitted and approved “Arboricultural Impact Assessment Report” ref. SHA 1480, dated November 2021.

The development hereby approved shall be carried out in accordance with the provisions of the Planning Fire Safety Strategy submitted and received by the local planning authority on 28 April 2021.

There is one main issue which is the effect of the proposed extension on the character, appearance and setting of the host dwelling, the adjoining dwelling and the surrounding area, including the Mortlake Conservation Area and nearby Listed Buildings.

The Council’s reason for refusal relates only to the proposed first floor extension. I agree that other elements of the proposed development would be acceptable. I shall therefore limit my further consideration to the disputed first floor extension.

The appeal dwelling is set in a secluded location, accessed via [name] and behind the larger dwellings on [name]. To the south lies the [name] site characterised by large industrial buildings and structures. This site is understood to be awaiting re-development. The cottage lies within the Mortlake Conservation Area (CA) which is characterised in this area by the spacious historic development adjacent to the [name] and the network of narrow alleyways linking the smaller scale, more intimate hinterland with the river frontage. A number of the buildings to the north on [name] are Listed. The adjoining dwelling, [address], is locally listed as a Building of [name] (BTM).

The National Planning Policy Framework (NPPF) makes clear that conservation areas and listed buildings are designated heritage assets. When considering the impact of a proposed development on the significance of a designated heritage asset, the NPPF advises that great weight should be given to the asset’s conservation. Significance can be harmed through alteration of the heritage asset or development within its setting. Statutory protection is provided by Section 66(1) and Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the 1990 Act) which apply to conservation areas and listed buildings respectively. These require that special regard/attention is paid to the desirability of preserving or enhancing the character or appearance of the heritage asset, including its setting.

The appeal dwelling comprises a modest cottage, believed to date from the early 19th century. The front elevation retains much of its original character but the cottage has undergone noticeable extensions and alterations to the rear. These include a single storey kitchen extension with a flat roof and at first floor a small, glazed extension. The proposed extension would be above the existing kitchen. It would be linked to the existing cottage by a glazed, flat roofed element that would replace and extend the existing glazed extension. This would ensure it was seen as distinct from the original cottage. The extension would be clad in larch timber boarding and I agree with the Council that this would be acceptable. It would have a shallow pitched roof with half hips. This would be noticeably lower than the roof of the original cottage. Coupled with the clear separation between the two built elements, the modest scale and height of the extension would ensure it was read as a subservient and sympathetic addition.

The Council is concerned that the contrast between the existing render finish of the kitchen extension and the larch boarding would appear discordant and that 2 the proposed fenestration would be different. However, in my view the unobtrusive render would sit comfortably below the cladding and although the proposed windows would not match the window in the existing kitchen, they would match those seen elsewhere on the rear as well as the front of the original cottage and would to my mind be in keeping with the dwelling as a whole.

Turning to the effect on the wider area, the proposed extension would be hidden from public views, including [name], by other buildings. There would be minimal intervisibility between the proposed extension and [address] owing to the juxtaposition between the two and existing extensions to that dwelling. This would ensure that there was no material effect on the setting of [address] or outlook from it. With respect to [address], this property has a large, mature garden and any views of the proposed extension would thus be at a distance and only glimpsed. Even from the garden any intervisibility would be limited by the boundary wall and vegetation. I am therefore satisfied that the setting and outlook from this dwelling would be protected.

[address] lies to the north of the appeal dwelling. It is an 18th century two storey house and is [name] listed. Its garden and rear elevation are visible from the first floor of [address]. The proposed extension would thus be visible from the house and garden of [address]. However, the distance of separation together with the modest scale of the proposed extension and the backdrop of the dominant [name] buildings would ensure that the outlook from [address] was protected. In terms of setting, [address] and the proposed extension would not be seen in the same view and the significant distance between the two buildings, together with intervening built structures and trees would ensure that there was no harm to the setting of the listed building.

I am further satisfied that the proposed extension, due to its modest scale, secluded position and sympathetic appearance, would preserve the character and appearance of the [name]. 11.Overall, in terms of the effect on the BTM, the CA and nearby Listed Buildings the effect of the proposed extension would be neutral and their character, appearance and setting would be preserved. The proposed extension would therefore comply with the requirements of the NPPF, national legislation and Policy LP3 of the Local Plan (LP), 2018, which requires development to conserve the historic environment of the borough, since it would have no material effect on the significance of the surrounding heritage assets.

It is concluded on the main issue that the proposed first floor extension would have no materially harmful effect on the character or appearance of the host building, the adjoining [address] or the surrounding area, would conserve the significance of the [name] and preserve the setting of nearby listed buildings including [address]. In consequence, it would comply with [name] LP1 and LP3 which, taken together, expect development to be of a high architectural and urban design quality such that it is compatible with local character and conserves the historic environment, including both designated and non-designated heritage assets. 3

Turning to conditions, I agree with the Council that in addition to the statutory commencement condition, conditions requiring the development to be carried out in accordance with the approved plans and in materials that match the existing building or as otherwise submitted are necessary in order to provide certainty and to protect the character and appearance of the host building and the surrounding area. A condition requiring compliance with the recommendations of the Arboricultural Impact Assessment Report dated November 2021 is also necessary to protect trees in the vicinity of the site. However, given the negligible effect on protected trees and the fact that most are located beyond the robust boundary walls surrounding the appeal site, I find conditions requiring the appointment of an arboricultural consultant, the submission of monitoring reports and the requirement for a pre-start meeting to be unnecessary and unreasonably onerous.

The Council suggests a fire safety condition to comply with the Mayor’s London Plan Policy D12. A fire safety strategy has been submitted and I agree that in accordance with Policy D12 and to secure the fire safety of the development compliance with it should be required. 15.Finally, the Council suggests a condition limiting powered construction equipment used on site to that capable of running on ultra-low sulphur diesel. However, whilst that may be good practice, I do not consider that this condition is necessary or reasonable in terms of making the development acceptable in planning terms. I shall not therefore impose these conditions. 16.For the reasons set out above and having regard to all other matters raised, I conclude that the appeal should be allowed.