Appeal 3287720

The appeal is allowed and planning permission is granted for “Part single-storey, part 2-storey side and rear extension. Roof extension involving rear dormer window and 3 front-facing rooflights” at [site address] in accordance with the terms of the application ref. 21/5151/HSE, dated 24 September 2021, 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 numbered or annotated: LOCATION PLAN; EXISTING BLOCK PLAN; PROPOSED BLOCK PLAN; 63/01B; 63/02B; 63/03B; and 63/04B.

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

The description of the proposed development in the heading above is taken from the Council’s decision notice and the appeal form. I have adopted this description of the proposed works as it is marginally more accurate than the one provided at section 4 of the application form.

The Council had no objections to the part single-storey, part 2-storey side and rear extension or to the 3 front-facing rooflights. The Council did not find that the proposed rear dormer window would cause an excessive loss of amenity for neighbouring properties for any reason. Rather, the Council considered that it would be harmful to the character and appearance of the host property and the area due to its alleged excessive size.

The sole main issue in this appeal is therefore the effect of the proposed rear dormer window upon the character and appearance of the dwelling and its surroundings.

[address] is mainly characterised by 2-storey, semi-detached houses with hipped roofs like no. 63 which forms a semi-detached pair with no. 61. The surroundings are residential in character and lie within one of Barnet’s high quality suburbs. The stock of established houses, the bands of mature hedges and other vegetation separating the road from the footways and the changes in gradient along the road all contribute to the quality of [address].

The appellant, amongst other things, wishes to create a loft floor, principally over the core of the original building, by constructing a new flat-roofed rear dormer over the extended roof. The Council refers to its Residential Design Guidance Supplementary Planning Document (SPD), adopted in October 2016. This document clearly carries weight as a material consideration in decision making but it should not be applied prescriptively to the exclusion of all other factors, including the physical circumstances and context of a site.

The SPD explains that in terms of scale, dormer roof extensions should normally be subordinate features on the roof and should not occupy more than half the width or half the depth of the roof slope. In terms of positioning, the SPD states more generally that adequate roof slope above and below the dormer is required on semi-detached properties and that dormer extensions should be set in at least a metre from a party wall, flank wall or chimney stack.

The appeal scheme would not comply with the SPD but there would not be a gross infringement of the guidelines. This is not a case where the dormer would effectively obliterate the rear roof slope. For instance, I estimate that the dormer would occupy about 71% of the width and about 63% of the height of the extended rear roof slope. I am satisfied that overall, it would be set sufficiently within the rear roof slope and not appear oversized or too dominant. This finding is aided by the proposed inclusion of windows of slightly shorter depth than those below at first floor level.

Of greater importance, in my view, is the fact that from the rear garden of the appeal property I saw that many nearby properties on the same north-western side of [address], between its junctions with [address] and [address], have large box-style dormers on their rear roof slopes. The examples I saw are at nos 53, 61, 67, 73, 83, 85, 87 and 89. There are others on the rear-facing roof slopes of various properties on [address] and [address], many of which occupy higher ground than the appeal property. Some of those rear dormers can also be picked out when standing in the vicinity of the junction with [address] and looking at the front of nos 61 and 63. All the rear roof additions I saw contribute to the local distinctiveness of the surroundings at the rear, given their number, size, scale, position and variety. Even if some or all of 2 them have come about through permitted development rights, such dormers are now established features to the extent that in itself, the introduction of another large rear dormer would not be out of character with this locality.

The Council does not seem to acknowledge this character and is too dismissive of the very large flat-roofed rear dormer at no. 61. That neighbouring dormer is a material consideration as it has a physical impact on this semi-detached pair of dwellings that needs to be taken into account. In the available views from surrounding back gardens, the proposed dormer would appear exemplary alongside it and restore a degree of balance to the rear roofscape of this semi-detached pair.

The significance of the context provided by a surrounding area was highlighted in an appeal decision (application ref. 19/5852/HSE and appeal ref. APP/N5090/D/20/3246697) allowing a similar proposal at [address]. Given the similarity of that scheme and the very short distance between that property and [site address] , I agree with the appellant that the Council should have attributed greater weight to that appeal decision than it did. Whilst each appeal is to be determined on its merits, the Inspector in that case reached a favourable decision based on the number of box-style rear and side dormers on surrounding streets, even without observing any such dormers on the nearby properties on [address] itself.

Drawing these threads together, recognizing that the rear roof slope of the appeal property is not readily visible from public vantage points and noting the proposed use of matching facing materials and fenestration details, I consider that the proposed rear dormer would not appear at odds with the established character of the locality nor overly large, excessively scaled or too dominant when viewed in the context of its surroundings. There would not be an unacceptable impact on the character and appearance of the host property and the neighbouring properties including no. 61, the other half of the semi-detached pair. There is sufficient justification for a departure from the guidance in the SPD having regard to the physical circumstances and context of this site.

I find on the main issue that the proposed rear dormer window would not harm the character and appearance of the dwelling or its surroundings. For the avoidance of doubt, I consider that the proposed development as a whole would exhibit a high standard of design, be sufficiently complementary, sympathetic and subordinate to the parent building and be respectful of the high quality suburban environment of [address]. There would no conflict with Policy DM01 of Barnet’s Local Plan Development Management [name] 2012 or with Policies CS1 and CS5 of Barnet’s Local Plan Core Strategy September 2012. Viewed in the round, those policies, amongst other things, seek to ensure development respects local context and distinctive local character by creating places and buildings of high quality design and respects the appearance, scale, mass, height and pattern of surrounding buildings, spaces and streets. They are consistent with the National Planning Policy Framework insofar as it relates to achieving well-designed places.

The absence of any material conflict with the development plan and the avoidance of any visual harm together outweigh the conflict with the guidance in the SPD. A departure from the SPD is therefore justified for the reasons previously stated relating to the particular circumstances of the property and 3 its surroundings. It is worth mentioning in this regard that the Council found that the single-storey and first-floor elements of the proposed side extension would not be directly compliant with the SPD but still found those parts of the development proposal to be acceptable in the circumstances of the case. I see no reason to disagree.

In addition to a condition setting a time limit for the commencement of development, a condition requiring that the development is carried out in accordance with the relevant approved drawings is necessary as this provides certainty. I have also imposed the Council’s other suggested condition to secure matching materials so that the development preserves the character and appearance of the dwelling and the locality.

For the reasons given above and having regard to all other matters raised and the absence of objections from local residents, I conclude that this appeal should be allowed.