Appeal 3314519

The appeal is dismissed.

I have used the description of development that was given on the decision notice and which was repeated by the appellant on the appeal form. This better reflects the scope of the proposed works compared with that which was given on the application form and which described the development merely as ‘loft conversation [sic] and extension’.

The main issues are the effects of the proposal on the character and appearance of the host property and the wider area, and upon the living conditions of neighbouring occupiers, with particular regard to visual impact and light.

The appeal property is a two-storey, terraced dwelling within a wider residential area comprising properties of similar style and age. The property has a subservient two-storey outrigger that is mirrored at No 52, with a gable end and central ridge running along the common boundary between both. An original void to the side of this adjacent to No 48 is occupied by a single-storey, flat roof extension, equivalent in depth to the outrigger, beyond which there is an open fronted, lean-to canopy to a further depth of around 3m. At roof level there is a ‘box-like’ dormer window extension occupying the majority part of the rear roof slope. The proposal would see the existing ground floor additions replaced with a wrap-around extension projecting 5m beyond the outrigger along the boundary with No 52 and 8.1m (according to an undisputed figure given by the Council) along the boundary with No 48. It is further proposed to enlarge the existing dormer by turning through 90-degrees and projecting it along the side facing roof slope of the outrigger.

The Council’s Residential Extensions, Basements and Conversions Guidance Supplementary Planning Document December 2018 (SPD) advises that, in order to remain subservient to the original house and avoid unacceptable impacts upon neighbouring occupiers, a single-storey extension should not project deeper than 3.6m for an attached property. It emphasises that an infill extension that fails to follow the stepped rear wall of an original dwelling will be discouraged because of the potential for harm to neighbouring properties. With regard to roof extensions, the SPD advises that they should be proportionate to the size of the original house, and any proposals that change the roof form should seek to preserve or enhance the existing appearance in terms of height, scale and visual interest. It recognises that dormer extensions are acceptable to the rear of a house but generally advises that they should be small-scale and windows of an appropriate design relative to others.

Although the single-storey extension would be significantly deeper than the SPD’s guidelines, I consider that it would appear as a well-conceived and integrated addition that would complement the existing building when viewed from the rear garden context of its setting. It would be residential in scale and form, with ample rear garden space retained ensuring that the plot would appear neither cramped nor overdeveloped.

During my visit, I saw that No 48 had a fairly shallow infill extension equivalent in depth to the existing infill at the appeal property and that No 52 was un-extended beyond the depth of its adjoining outrigger. There was an approximate 1.8m high boundary fence to both side adjoining properties. The circumstances and relationships between the appeal property and both neighbours appeared routine and typical of those between most terraced houses.

The extension would project from the rear wall of the main part of the house and along the common side boundary with No 48 to a depth of around 8m, well beyond the maximum depth of 3.6m that is normally required by the SPD. Moreover, it would extend beyond the existing extension to No 48 by 5m and exceed the depth of the existing lean-to canopy at the appeal property by around a further 2m. With a side parapet wall measuring 3.05m high, it would also extend well above the existing boundary fence. In my assessment, the extension would impose itself upon the outlook from the ground floor living space and rear garden to No 48 as a visually dominant and intrusive addition that would noticeably alter the existing arrangement and which would create a significant and unacceptable sense of enclosure. I am not persuaded by any substantive evidence that levels of either natural light or sunlight to the neighbour’s property would be diminished by any significant degree. Nevertheless, the resulting visual impact of the proposed extension appears to me to be precisely that which the SPD seeks to advise against.

Although there would be less of an impact upon the outlook from internal living space to the opposite neighbour at No 52 due to the shared outrigger, the depth and height of the extension beyond the existing rear building line would equally impose itself as a visually dominant and intrusive addition when seen from this neighbour’s adjoining garden space.

Turning to the proposed loft conversion. This would include a ‘box-like’ addition to the side shallow roof slope of the outrigger that would amalgamate with the existing rear facing dormer window. It would be set just marginally up from the eaves and away from the rear elevation of the dwelling, with its height significantly above the ridge to the outrigger and just marginally below the ridge height of the dwelling’s main roof. It would unquestionably alter the form and shape of the dwelling’s existing roof, which would be virtually indiscernible when viewed from the rear, with barely any of the original roof slope remaining. In my assessment it would appear disproportionate to the scale of the original roof and would create a top-heavy appearance that would damage the character and appearance of the house and the rear garden setting of its surroundings. In this regard the proposal would directly conflict with the SPD guidance for roof extensions/loft conversions and would again represent a form of development which the SPD advises against.

My attention has been drawn to other similar roof extensions in the area, including at No 52, which the appeal proposal would largely mimic and create a sense of balance with. I am not aware of the planning history at No 52 but evidence shows that equivalent developments at Nos 64, 74, 75, 78, 92 and [address] have been undertaken as permitted development following the issue of a Certificate of Lawful Development in each case. I am also mindful of an enforcement appeal decision in 2019 for a similar type of development at [address] in the London Borough of Lewisham ([name]/C5690/C/19/ 3221456), which the appellant has drawn to my attention.

In terms of the area’s character, the number of similar extensions in the surroundings is not significant in my opinion. I observed that the rear outriggers to the majority of dwellings in [address], visible from the appeal site, or elsewhere from the public domain, retain their original roof form. Those that do not and display a dormer extension to this part of the dwelling are in the minority and in my view stand out as incongruous and inharmonious. There has not been a sea change in the prevailing character of these terraced properties to suggest in this instance that normal guidelines for roof extensions/loft conversions should be set aside.

The appeal example at [address] relied upon a reasonable degree of certainty that a very similar form of roof extension would be likely to be built on that property if the enforcement appeal in that case was upheld. However, I have no substantive evidence before me to show precisely what size or form of dormer could be built at the appeal property as permitted development. Neither is it for me to determine this as part of this appeal. As such, I cannot make any reasonable comparison between the case at [address] and the appeal proposal. However, I accept that there is a likelihood that some similar form of dormer could be constructed at No 50 as permitted development. This is a material consideration and I attach some weight to this argument as a potential fallback position although this is tempered by the fact that I cannot be precise about the size or scale of what would be possible given the limited amount of information presented to me.

When considering the appeal proposal as a whole, and weighing matters in the balance, I find overall that there is insufficient weight in favour of the proposal to outweigh the harm that I have identified to the character and appearance of the property and the wider area from the proposed roof addition, and the harm that I have identified to the neighbours’ living conditions as a result of the proposed single-storey extension. The absence of any neighbour objections does not alter my findings on these matters.

Based upon my findings, there would be clear conflict with Policies DH1, DH(a) and DH(b) of the Royal Greenwich Local Plan: [name] with [name] 2014 and Policy D3 of The London Plan 2021 insofar as they require new development, including residential extensions, to achieve high quality design that responds positively to local context through, amongst other things, respect for the scale and appearance of a host building and established development pattern, and to avoid the unacceptable loss of amenity to adjacent occupiers. For these same reasons, the proposal would conflict with the National Planning Policy Framework’s objectives for achieving well-designed places. The conflict with both national and local policy means that the proposal would not represent a sustainable form of development.

Accordingly, and having regard to all other matters raised, I conclude that the appeal should be dismissed.