Appeal 3305640

The appeal is dismissed.

The main issue is the effect of the proposed extension on the character and appearance of the area.

The appeal relates to a two-storey mid-terrace house with a two-storey outrigger at the rear. The loft has already been converted to provide habitable rooms, with rooflights on the front roof pitch and a dormer across the full width of the rear roof slope. There is also a dormer containing a bedroom above the rear outrigger, which the appellant now wishes to extend; this would facilitate an internal reconfiguration to provide an additional bathroom within the property. There would be no change to the height or width of the dormer, but it would be lengthened to finish approximately 0.77m from the end wall of the outrigger below.

There are many examples of extensions above rear outriggers on other properties on the same side of [address] as No 35, and I accept the appellant’s point that L-shaped and flat-roofed box dormers form part of the character of the area. However, the evidence before me (including my observations during my site visit) indicates that most extend to no more than approximately half the length of the outrigger below; they are generally therefore similar in proportion to the existing rear dormer on the appeal property’s outrigger, and smaller than the extension proposed in this case.

The prevailing pattern whereby roof extensions on outriggers are set back by a generous distance from the end of the original building below means their often cumbersome and boxy form does not overwhelm the outrigger, or significantly detract from their traditional pitched roof form. This means that the contribution of the rhythms and roofscapes of rear outriggers can still be seen and appreciated from surrounding dwellings and gardens. While there are some exceptions (and I return to specific examples in a moment), based on all the evidence it seems to me that roof extensions occupying as much or more of the rear outrigger as proposed in this case are very limited in number rather than a significant feature of the area.

I also saw that the way in which most dormers step back from the ends of the outriggers means that the rear gardens do not feel closely hemmed-in and retain what is, for a reasonably densely-developed suburban area, a generous sense of spaciousness. The retained pitched roof form of (most of) the outriggers and the sense of spaciousness are both factors which, in my view, make very positive contributions to the character and appearance of the area.

While the proposed extension would not be visible from public spaces, the limited set-back from the end of the outrigger below would result in it being a prominent and intrusive addition when seen from the rear rooms and gardens of neighbouring properties both in [address] and facing the appeal property from [address]. It would diminish and largely subsume the traditional form of the outrigger. It would also, by bringing the third floor of the dwelling closer to the main part of the rear gardens, lead to some loss of the sense of spaciousness at the rear of the terrace. I consider that both of these effects would be detrimental to the quality of the character and appearance of the area.

The appellant has drawn my attention to several of the other roof extensions within the surrounding area. No [address] is a semi-detached dwelling with a large L-shaped extension straddling both the outrigger and the main rear roof pitch. I have not been provided with any further information as to how or when it came into being. From the aerial photograph provided by the appellant, as well as the limited view of it which was possible from [address] during my site visit, I consider that is a somewhat unsympathetic addition to that property; it dominates and detracts from the original pitched roof form of the rear outrigger below.

Based on the photographs provided, the large L-shaped dormers which have been added to Nos 21 and [address] are bulky and cumbersome additions which bear little visual relationship to the scale or form of the original dwellings below. That at No 21 was granted a Certificate of Lawful Development (“an LDC”) in 20151; no further information is before me in respect of No 55. However, they lie four streets away to the east of the appeal site, and so in any event are quite unrelated to the character and appearance of its immediate surroundings.

Nos 59 and [address] sit further north in the same terrace as the appeal property. Both have large dormer extensions on the outrigger; the one at No 59 appears similar in proportion to that proposed in this appeal, while the example at No 69 is larger and extends to the end of the outrigger. In both cases the original form of the outrigger has been substantially lost and, again on the basis of the images put before me, some harm caused to the character and appearance of the dwellings. As with No 24, this harm means that I do not 1 [name]: 15/P3673 consider these examples provide a substantive justification for allowing the appeal scheme.

The roof extension at No 69 was in part granted an LDC in 20172, the Council having established that it complied with the conditions and limitations within Schedule 2, Part 1, Class AA of the Town and Country Planning (General Permitted Development) (England) Order 2015 (“the GPDO”). The Council did not – indeed, could not – take into account broader matters such as the effects on character and appearance which are considered when determining a planning application. The Council concluded in the case of No 69 that the size, dimensions and siting of the roof extension complied with the GPDO. In respect of No 59, the Council commented that “it is unclear as to whether it is lawful as no permission or LDC exists on record”; the appellant’s evidence did not shed any further light on this matter. It is perhaps notable though that the appellant has not argued that the proposal before me would comply with the relevant limitations in the GDPO, so it this has not been put forward as an alternative route to achieving the same, or a similar, development in this case.

Finally, the appellant drew my attention to extensions over the rear outriggers at Nos 7,9 and [address], three streets west of the appeal site. These appear to be identical (for all relevant intents and purposes, as far as this appeal is concerned), and were granted planning permission in 2016 (No 73) and 2017 (Nos 94 and 115). The officer report in respect of No 7 indicates that the end of the extension is set back from the rear wall of the outrigger below by some 1.5m, approximately twice as far as is proposed in this case; the Council’s report for No 11 also explained that the [address] extensions are of a “mansard” design, with rear and side walls angled at approximately 70 degrees. Summarising the No 11 proposal, the Council considered that these features “[minimised] the bulk of the extension and [ensure] the character and form of the original [outriggers are] retained”. Based on the evidence before me, I agree; these significant differences also mean that the three [address] examples are not directly comparable to this appeal scheme.

The appeal site is on the boundary of, though outside, the [address] Conservation Area (“the LRCA”); I therefore have a statutory duty to pay special attention to the desirability of preserving or enhancing the character or appearance of the Conservation Area. As heritage assets are irreplaceable, the National Planning Policy Framework (“the Framework”) states that they should be conserved in a manner appropriate to their significance (paragraph 189). It goes on to advise that any harm or loss requires clear and convincing justification (paragraph 200), and that any harm that is less than substantial must be weighed against the public benefit of the proposal (paragraph 202).

Among other things, the Council’s [address] Character Assessment identifies that “unsightly box-like rear roof extensions”, including some on [address] outside the Conservation Area itself, are a negative feature of the LRCA. For the reasons I have set out in paragraph 7 above, I consider that the detrimental impact of the proposed extension would be felt within the rear rooms and spaces of properties on the east side of [address] backing onto the appeal site. The harm to the character and appearance of the area would 2 [name]: 17/P3602 3 [name]: 16/P0185 4 [name]: 17/P2573 5 [name]: 17/P2092 therefore encompass a small part of the LRCA. In the Framework’s terms, the harm that this would cause to the significance of the Conservation Area as a designated heritage asset would be less than substantial; however, no public benefits arising from the scheme have been put forward by the appellant.

I conclude that the proposed development would conflict with Policy CS14 of the 2011 [name], [name] D2 and DM D3 of the 2014 [name] and Policies Plan, and Policies D3 and D4 of the London Plan 2021. Together, and among other things, these policies seek to ensure that development relates appropriately to the scale, proportions and massing of surrounding buildings, and that alterations and extensions to existing buildings respect the form, scale and bulk of the original building, with roof forms of an appropriate size, type and form. For the same reasons I find conflict with the provisions of the Framework in respect of protecting the historic environment.

The proposed extension would be harmful to the character and appearance of the surrounding area, would not preserve or enhance the character or appearance of the [address] Conservation Area, and 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, the appeal is therefore dismissed.