Appeal 3279571

The appeal is dismissed insofar as it relates to the mansard roof extension with roof terrace, lead-clad dormers and painted metal balustrade. The appeal is allowed insofar as it relates to the front extension under existing ground floor bay window, insertion of aluminium-framed sliding doors to rear ground floor and first floor roof terrace, insertion of rooflights in rear first floor roof terrace and second floor outrigger, rear outrigger extension to the second floor and improved access to second floor terrace, and, the removal of existing windows on rear and side elevations to facilitate outrigger extension at [site address] in accordance with the terms of application [name]/21/00780, dated 3 February 2021, and the plans submitted with it so far as relevant to that part of the development hereby permitted and subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans insofar as they relate to the elements allowed in this appeal: kAD DPR 00 001 Rev P0, kAD DPR 01 100 Rev P0, kAD DPR 02 100 Rev P0 and kAD DPR 03 100 Rev P0.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the existing building.

Following the decision of the Council, the appellant has submitted an updated Daylight and [name] as new evidence in support of the proposal. The Procedural Guide to Planning Appeals – England states that the appeal process should not be used to evolve proposals and is clear that revisions intended to overcome reasons for refusal should normally be tested through a fresh application.

I have had regard to the [name] and the degree of engagement of all parties with the issue of daylight and sunlight. As a Householder Appeal, the Council and notified third parties have not had the opportunity to comment on the revised information. In the interests of fairness, I have therefore determined the appeal without reference to the revised document and on the basis of the information that was before the Council when it made its decision and on which all parties were consulted.

The site lies close to the Chelsea Conservation Area (CA). There is no dispute between the main parties that the proposed development would not have an adverse effect on the character or appearance of the CA. Pursuant to the duty under s72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, having considered the proposal and visited the site, I concur with that view. The distance from the CA and arrangement of intervening development ensure that the site is isolated from main views into and out of the CA. Accordingly, it is my view that the development proposed would preserve the character and appearance of the designated area and I shall make no further reference to this matter.

The main issues are the effects of the proposed development on: • the character and appearance of the building and locality • the living conditions of neighbouring residents with particular regard to daylight, sunlight and sense of enclosure.

[address] is a narrow road flanked by terrace buildings set behind shallow enclosed frontages. The buildings consist of small sections of consecutively developed terraces and some individually styled buildings. The buildings along the street mainly appear as 3 storeys with a continuous front elevation and parapet, or 2 storeys with mansard and dormer roof forms.

The appeal site is a mid-terraced unit in a group of 4 buildings finished in similar brickwork and with some common design features. Despite numerous alterations to the front and rear elevations of the terrace, it appears as a cohesive group. Of the group, 3 have a consistent parapet line; the flanking buildings have mansard roof forms at second floor level.

The proposed roof extension would increase the height of the building by an additional floor. This would include large party wall upstands forming the sides of the roof extension. These would stand proud of the adjacent roofs. Although the dormer elevation would be set back from the front parapet, the significant addition would be visible in views along the road and from properties to the front and rear. It would not appear incongruous in form on account of the numerous other examples of mansard roof extensions, however, the increase in scale and massing of the unit would jar significantly with the neighbouring buildings and the predominant scale of buildings along the street.

The roof extension would interrupt the existing continuous level of the terrace’s roofscape and depart from the characteristic massing of development on this part of the road. In turn, notwithstanding the existence of other mansard roofs, this would cause significant harm to the character of the group and the [address] streetscene.

I acknowledge that an individually styled converted building close to the midpoint of the road and some properties with roof alterations lying opposite it, provide examples of taller development within the street. However, these are very much in the minority and, in any case, the existence of development elsewhere does not represent an appropriate reason to find in favour of a proposal that I have determined would cause harm.

I also note a previously approved roof extension to [address] ([name]/17/03151). That extension has not been constructed. However, if it were, it would have a greater degree of visual containment on account of the deep parapet. Furthermore, that decision pre-dates the current policies in the Royal Borough of Kensington and Chelsea Local Plan [2019] (LP) and precedent is rarely an argument that should carry great weight in planning decisions which should be made on their own merits in the context of the development plan and other material considerations.

At my site visit, I observed the presence of railings above several of the roofs on the street. However, there is little before me to indicate that these are authorised. Although minor in nature, the addition of railings would serve to draw the eye to the roof extension and the proposed rooftop terrace. Moreover, they would not be characteristic of the simple lateral detailing at the existing roofline.

For the above reasons, I find the mansard roof extension would cause the scale and massing of the building to starkly contrast with the neighbouring dwellings and predominant scale of development along the street. The proposed railings would draw focus to it and appear as an unsympathetic addition to the roof. Those elements of the proposal would conflict with Policies CL1, CL2, CL6, CL8 and CL9 of the LP as they require development to respect and contribute positively to the character and appearance of buildings and the townscape.

The proposed extension and alterations to the rear of the property would be small scale. Contained to the rear of the building, they would not contribute to the [address] streetscene and, in the context of other alterations to the rear of neighbouring buildings, would have a neutral effect on the character and appearance of the building and the locality. Furthermore, there is no dispute between the main parties that an extension under the existing front bay would not have an adverse impact on the [address] streetscene. These elements of the proposal would be consistent with the aims of Policies CL1, CL2, CL6, CL8 and CL9 of the LP as they seek development to achieve the foresaid aims.

The appeal site is 3-storey mid-terrace dwelling with a stepped rear elevation. The ground floor accommodation extends close to the rear site boundary with only a very confined yard area between. Beyond is a commercial building fronting on to [address]. This is set a similar distance from the common rear boundary such that there is very little space between the rear elevations of the buildings. The gap widens at the upper floor levels where the rear projecting elements of the building are shallower and above the initial 2-storey height of the building to the rear. This is a similar arrangement at other properties within the block.

The position of the roof extension close to the rear elevation would present as an additional floor above the height of the existing building. In the context of tight-knit development, I find the combined effect of the successive roof and second floor extensions would heighten the sense of enclosure to the rear of the neighbouring buildings.

In the adjacent neighbouring amenity space at [address], the effect of the set-back second floor extension in isolation would be limited, however, the roof extension would loom large over the constrained outside area to overbear on users of that space. This would cause significant harm to the living conditions of neighbouring occupiers as an overbearing and enclosing form of development.

Despite the roughly south-eastern rear-facing elevation of the terrace, the close proximity and heights of the buildings limits the amount of direct sunlight reaching lower rear openings and amenity areas in the vicinity. It is clear from the extensive use of glazing, rooflights and other translucent materials in alterations to the rear of the terrace, and in the proposals themselves, that natural lighting of the interior spaces is important to occupiers.

The increased height of the second-floor extension and roof addition would cause some degree of additional afternoon overshadowing to properties to the north. The roof extension would cause some loss to those properties on the opposite side of the road. However, I find that the extent of those losses would be for a limited period in the day and such any effect on neighbour’s living conditions would not be material.

Furthermore, the effects of the additional volume of development on ambient daylight would be negligible. The siting above the existing terrace, where spacing to the buildings front and rear are more generous than at lower levels, would have little effect on the overall amount of light reaching habitable room openings and outdoor amenity spaces. Accordingly, I find that existing daylight levels would be substantially maintained.

Taking the above together, whilst I have found in favour of the appellant with regard to the effect of the proposed rear and roof extensions on levels of sunlight and daylight, these do not outweigh the significant harm that would arise from the roof extension as an overbearing form of development. This element of the proposal would conflict with Policy CL5 of the LP as it seeks prevent harmful increases in the sense of enclosure to existing neighbouring gardens.

In support of the appeal, the appellant contends that the proposals would add to and optimise the usability of existing space. It would provide an additional room to facilitate home working and to make efficient use of the land. The extensions would be finished in high quality materials and would remove an ongoing maintenance burden associated with the existing flat roof. However, as benefits that are not necessarily dependent on the specific detail of the proposals before me, I find those arguments are of limited weight in support of the development.

I have considered the suggested conditions from the Council and had regard to Paragraph 56 of the Framework and the National Planning Practice Guidance in terms of the use of planning conditions. In addition to the standard condition limiting the lifespan of the planning permission, I have imposed a condition specifying the relevant drawings as this provides certainty. A condition requiring use of matching external materials is reasonable in the interests of preserving the character and appearance of the locality.

For a development of minor alterations to an existing building that will not introduce new drainage implications or materially increase the footprint of the building, I find that a condition requiring a comprehensive flood risk assessment and sustainable drainage strategy to be unnecessary and unreasonable in the circumstances of the case.

[name] have found in favour of the appellant with respect to the matters of living conditions associated with daylight and sunlight impacts, the proposed mansard roof extension and roof railings would significantly harm the character and appearance of the area. The roof extension would cause harm to neighbour’s living conditions as an overbearing form of development. Those aspects of the proposals would conflict with the development plan taken as a whole and there are no material considerations that indicate the decision should be made other than in accordance with the development plan. Therefore, I conclude that those elements of the appeal should not succeed.

For the reasons given, the appeal should be allowed insofar as it relates to the front extension under the existing ground floor bay window, insertion of aluminium-framed sliding doors to rear ground floor and first floor roof terrace, insertion of rooflights in rear first floor roof terrace and second floor outrigger, rear outrigger extension to the second floor, improved access to second floor terrace and the removal of existing windows on rear and side elevations to facilitate outrigger.