Appeal 3331175

The appeal is dismissed insofar as it relates to the construction of a single-storey side and rear wraparound extension, enlargement of first-floor side window, and enlargement of first-floor rear window. The appeal is allowed insofar as it relates to the reinstatement of original front porch and planning permission is granted for the reinstatement of original front porch at [site address] , London [postcode] in accordance with the terms of the application, Ref 23/2217/HD, dated 3 July 2023, so far as relevant to that part of the development hereby permitted and subject to the following

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

With the exception of the single-storey side and rear wraparound extension, enlargement of first-floor side window, enlargement of first-floor rear window for which planning permission is not granted, the development hereby permitted, namely the reinstatement of original front porch, shall be carried out in accordance with the following approved plans: • 42-A-P-Lo-00 (Location Plan) • 42-A-P-04-GF [name] (Ground Floor Plan as Proposed) • 42-A-P-05-FF [name] (First Floor Plan as Proposed) • 42-A-P-03-RF [name] (Roof Plan as Proposed) • 42-A-E-03 (Side (East) Elevation as Proposed) • 42-A-E-02 (Side (West) Elevation as Proposed) • 42-A-S-BB-01 [name] (Section BB as Proposed)

The reinstatement of the front porch hereby permitted shall be carried out in timber to match the existing dwelling.

The description of development used in the banner heading and my formal decision above is taken from the appeal form and the decision notice issued by the Council. I have used it in preference to the wording on the planning application form as it provides a more accurate description of the proposal.

The Government published revised versions of the National Planning Policy Framework (“the Framework”) on 5 September 2023, replacing the July 2021 version extant at the time the application was determined, and again on 19 December 2023. The amendments made did not have any bearing on the main issues in this appeal, and it was not therefore necessary to seek comments from the main parties on the updated Framework. [name] have referred to specific paragraphs of the Framework, the numbering used is that of the December 2023 version.

For the reasons that follow, I find the proposed reinstatement of the front porch to be acceptable, and it is clearly severable both physically and functionally from the other elements of the proposal. Therefore, although neither party specifically requested me to do so, I intend to issue a split decision in this case and grant planning permission for the reinstatement of the porch.

The main issues are the effect of the proposed development on: • The character and appearance of the Plumstead Common Conservation Area (“the PCCA”); and • Living conditions for occupiers of the neighbouring property No [address], with particular regard to outlook and enclosure.

The appeal site is within the PCCA, and I have a duty to pay special attention to the desirability of preserving or enhancing the character or appearance of that conservation area. As heritage assets are irreplaceable, the Framework states that they should be conserved in a manner appropriate to their significance (paragraph 195). It goes on to advise that any harm or loss requires clear and convincing justification (paragraph 206) and that any harm that is less than substantial must be weighed against the public benefit of the proposal (paragraph 208).

The PCCA is dominated by the extensive open spaces of [name] and [name], and the housing developed around their fringes; these are the principal elements which define the character of the conservation area. The 2010 [name] (“the [name]”) describes the part of the PCCA including the appeal property1 as having “mixed good 19th century terraced housing retaining much original character”.

The appeal property is a two-storey Victorian house, within a consistent terrace on the south side of [name]. The street elevation of the terrace 1 “Character Area 3: [name]” retains its traditional style; houses have canted bay windows (every sixth house, of which No 256 is one, has a two-storey canted bay window under a gable), and open porches. At the rear, although some properties have been modified or extended over the years, the regular two-storey “outrigger” returns (shared between adjoining pairs of houses) give the terrace a strong and consistent overall rhythm, and illustrate the historic pattern of development. Many of the outriggers retain a side-facing bay window to the ground-floor dining room, an unusual feature which adds visual interest.

Rear gardens are narrow but relatively long, providing a reasonably spacious setting in which the form of the terrace can be seen from surrounding properties. The appeal property and the wider terrace of which it is part make a positive contribution to the PCCA, because of their orderly appearance and the way in which they are illustrative of the prevailing pattern of development in the area.

The Council’s 2018 [name], Basements and Conversions Guidance Supplementary Planning Document (“the SPD”) advises that, where houses were originally built with a rear addition, “infill extensions” should maintain the stepped appearance of the property. The Character Appraisal identifies “wrap around” rear extensions which infill the L-shaped space and project to the rear of the traditional building line as having been detrimental to the character of the PCCA; it goes on to advise that the size, form and appearance of rear extensions should take account of the characteristics of the original house, and maintain an architectural unity with both the individual house and the terrace as a whole.

There are several elements to the proposed development. At the rear of the house, a single-storey extension with dual-pitched roof would be built wrapping in an L-shape around two the outrigger. This would span the full width of the plot and would project a maximum of around 4m beyond the end of the outrigger along the boundary with No 260 to the east; it would have an angled (or chamfered) rear wall and so would not project as far on the side adjoining No 256. The four existing uPVC windows at the rear of the first floor would be replaced with timber sashes; two of these (one on the side elevation of the outrigger, and the one on its rear) would be larger than the existing windows. At the front of the appeal property, unlike most (though not all) of the other houses in the same terrace, the timberwork above the open porch has been removed. As part of the appeal scheme, this would be reinstated in a style matching the original.

The broad footprint and shallow roof pitches of the proposed rear extension would give it a horizontal emphasis which would not reflect the proportions of the existing house. The wraparound form of the extension would envelop the ground floor of the outrigger which, with the open plan internal layout which would result from the total (or near total) removal of the existing side and end ground floor walls of the outrigger, would mean that the original shape of the building would no longer be discernible at ground floor level. The side-facing bay window on the outrigger would also be lost.

The rear extension would not be in public view, but would be seen from the rear of surrounding dwellings; it would lead to the loss of the stepped form of the rear of the appeal property, in a way which both the SPD and the [name] seek to avoid, and which has already harmed the character of the PCCA elsewhere. The loss of the stepped profile would be accentuated by the proposed angled rear wall, which would not be in keeping with the regular form of the original terrace. The proposed rear extension would also result in the removal and loss of the side-facing bay window on the rear outrigger, which is a characteristic feature of at least some of the terraces of housing around [name].

The appellant drew my attention to other L-shaped rear extensions which have been granted planning permission within the same terrace, at Nos 2542, 2803, and [address]. The drawings for those three approved schemes were included in the appellant’s evidence, but I have not been provided with the reasons why the Council allowed those developments in the face of the guidance in the SPD and the [name].

The Council’s officer report for the appeal scheme proposal referred to the “relatively large wrap around extension” at No 300 but explained that it was “smaller in scale and height” than the extension in this case. That reasoning is not totally borne out by the appellant’s calculations, which indicate that the proposed extension would be just under 30m3 smaller than that at No 300; the maximum (ridge) height of the extension at No 300 is higher than proposed here, although the eaves height is lower. Nevertheless, the aerial photographs of the rear of the terrace provided in both main parties’ evidence shows how the ground floor extension at No 300 dominates the rear outrigger of that house, so to my mind it is illustrative of the potential harmfulness, rather than the acceptability, of a large rear wraparound extension.

The appellant’s calculations show that the appeal scheme would be slightly larger in volume than the approved extensions at Nos 254 and 280 (both of which would incorporate a small “courtyard” next to the building’s main rear elevation). Again though, the information before me does not fully explain the full circumstances of these other examples, and I do not find them determinative. In any event, I have considered this appeal on its own merits and have found that it would cause harm as identified above.

The Council considered that the proposed enlargement of two rear windows would not cause unacceptable harm to the character and appearance either of the appeal property or the wider area. I agree with their analysis. I also acknowledge that the scheme would be carried out using high-quality materials which would be in keeping with the appeal property and the terrace as a whole. However, a lack of harm in these respects would not outweigh the other harm which would arise at the rear of the house as a result of the development.

Accordingly, I find that the proposed rear extension would harm the character and appearance of the host property, and would not preserve or enhance the character of the PCCA. In the Framework’s terms, the harm to the significance of the conservation area as a designated heritage asset arising from the proposal would be less than substantial.

I acknowledge that there would be a significant benefit to the appellant in being able to enlarge his home, though this would be a private benefit rather than a public one. The appellant indicated that the scheme “will facilitate much 2 [name]: 19/2904/HD 3 [name]: 20/3099/HD 4 [name]: 21/2755/HD needed thermal upgrades to the building’s fabric”; though it was not explicitly put forward as such, I acknowledge that any significant reduction in carbon emissions (for example) would be likely to be a public benefit. However, there is nothing before me which explains how or why any such upgrades or possible related improvements to energy efficiency would be dependent on the construction of the extension. In any event, such public benefits as might arise would be relatively limited, and therefore carry only modest weight in favour of the scheme. They would not outweigh the harm to the heritage asset, to which I must attribute great weight.

I therefore conclude that the proposed rear extension would conflict with Policies DH1, DH3 and DH(h) of the 2014 Royal Greenwich Local Plan Core Strategy (“the LPCS”) and Policies D3 and HC1 of the London Plan 2021 which, among other things, seek to ensure that development takes account of the architecture of surrounding buildings, and that heritage assets including Conservation Areas are protected and enhanced. This part of the proposal also conflicts with the provisions of the Framework which seek to conserve and enhance the historic environment.

The Council raised no objection to the proposed reinstatement of the front porch. Having visited the property, I agree; No 258 is one of very few houses in the terrace which does not retain the original (or at least original-looking) timberwork around the open front porch. Its reinstatement would be a positive factor of the scheme, by which the character and appearance of the Conservation Area would be enhanced. In respect of this element of the proposed development, there would not be conflict with the development plan policies identified above, nor with the provisions of the Framework which seek to conserve and enhance the historic environment. It would also be clearly severable from the rest of the proposed development, and I therefore propose to grant permission for this element of the scheme.

The ground floor window on the main rear elevation of No 256 next to the appeal site serves a habitable room. The gap between the outrigger of the appeal property and that of No 256 is narrow, and the two rear gardens are separated by a timber panel fence somewhere around 1.8m in height. The outlook from the room at the rear of No 256 is already constrained by the narrowness of the rear garden alongside the outrigger, the boundary fence, and the presence of the appeal property outrigger.

The proposed extension would have an eaves height on the boundary of around 2.4m and would extend beyond the end of the appeal property’s existing outrigger. The height and length of the proposed extension, and its proximity to the boundary, would further restrict the outlook from the rear of No 256, and there would be a similar increased sense of enclosure in the narrow part of its rear garden. In these respects, the proposal would therefore have an unacceptable adverse effect on living conditions for the occupiers of this neighbouring property. That there is already a “tunnelling effect” caused by the existing outriggers and extensions does not justify allowing further significant harm to living conditions.

The appellant has explained that within No 256 the wall between the original front and rear reception rooms has been removed, creating a single large dual-aspect room; it is therefore argued that the affected rear window is “not the primary source of outlook from the room it serves and it is not considered reasonable to afford that window the same level of protection one may afford a principal window”. I do not agree with that argument; I saw on my site visit that the houses are relatively deep and narrow and therefore, while the rear windows may be smaller than the bay windows at the front, their south-facing outlook onto the privacy of the rear garden, albeit a narrow part of the rear garden, means that they are likely to make a valuable contribution to the quality of living conditions for the occupiers.

The appellant’s evidence included modelling of the view from the rear window at No 256 of the appeal scheme, and also the approved developments at Nos 254 and 280 which I have referred to above. I accept that they appear to show that the appeal scheme would be likely to have a comparable, or lesser, impact on outlook than those two developments. However, for the reasons which I have already set out, I do not consider that those other permissions represent a precedent or justification for the appeal scheme, which I have assessed on its own merits. The illustration of the appeal scheme, showing the bulk of the extension which would be seen above the boundary fence and in front of the rear outrigger of the appeal property, confirms my view that it would have a harmful effect on outlook.

The appellant’s statement included a diagram showing that, in elevation, the extension would comply with the “45° approach” described in the BRE guidance5. However, while the 45° approach may provide a reasonable guide in respect of likely effects on daylight, that the proposed development would comply with one part of that test does not negate or outweigh the other harm in respect of outlook which I have found.

I also note that the current occupiers of No 256 responded to the Council during the planning application consultation. Their comments that “we support the design of the rear extension because the angled rear building line reduces the massing [...] and hence reduces the loss of the residential amenity” and “we support the height and design of the side extension [...] and would not like to see it extend any further in height” do not seem to me to be quite as unqualified in their support for the development as they have been interpreted by the appellant, given their reference to the loss of amenity and the implication that the height of the extension would be at the limits of what they consider acceptable. In any case, I have a duty to consider the potential impact on future neighbouring occupiers as well.

The proposed rear extension would result in significant harm to living conditions for occupiers of No 256 arising from an unacceptable loss of outlook and an increased sense of enclosure. It would therefore conflict with Policies DH1 and DH(a) of the LPCS, and Policy D3 of the London Plan 2021. Together, and among other things, these policies seek to ensure that development functions well, and respects the amenity of adjacent occupiers (including in respect of outlook).

In addition to the standard time limit condition (1), I have specified the approved plans so as to provide certainty (2), and to protect the character and appearance of the host property and the [name] have imposed a condition 5 Site Layout Planning for Daylight and Sunlight: A Guide to [name] (3rd edition), BRE, 2022) requiring the reinstated front porch to be of timber to match the rest of the building (3).

I have found the proposed reinstatement of the front porch to be acceptable and, indeed, consider that it would enhance the conservation area. As it is clearly severable from the rest of the development, I will grant planning permission for that part of the scheme.

The rear extension would not preserve or enhance the character or appearance of the Plumstead Common Conservation Area, and would cause unacceptable harm to neighbours’ living conditions. It would conflict with the development plan taken as a whole. There are no material considerations, including those of the Framework, which indicate that the decision should be made other than in accordance with the development plan.

For the reasons given above I conclude that the appeal should be allowed in part and dismissed in part.