Appeal 3340592

The appeal is dismissed.

The Council raises no objection to the proposed ground floor rear extension and the new conservation style roof lights. From the submitted evidence, I see no reason to disagree with the Council on these elements of the appeal scheme.

Therefore, the main issue is the effect of the proposed dormer extension on the character and appearance of the host building and the local area.

The new dormer would be placed onto the rear roof of the appeal property, which is a 2-storey end terrace dwelling within the [address] Conservation Area (CA). To my mind, the CA derives its significance as a designated heritage asset mainly from the rich variety and architectural quality of the residential buildings within it, which often contribute to attractive streetscapes. I saw that roof level extensions are a common feature of properties within the CA and that some were modern in design. I have paid special attention to the desirability of preserving or enhancing the character or appearance of the CA.

Although not identified as a designated heritage asset, the appeal dwelling typifies the traditional style, built form, period features and proportions of many properties within this part of the CA. As such, it adds to the sense of general unity and broad cohesion in the general appearance of the existing buildings. For these reasons, I consider that No 73 positively contributes to the character and appearance of the CA.

The proposal follows two separate rear roof level extensions that were both refused planning permission at appeal. By amending the appeal scheme in the light of the findings of earlier Inspectors, and by reference to other recently approved rear dormer extensions in the CA, the appellant considers that the previous concerns raised have been addressed and satisfactorily resolved.

The new dormer would be contemporary in style with zinc clad walls and one side angled to follow the end of the hipped roof. It would be a sizeable addition, covering a major part of the host roof with a wide elevation facing the back garden of No 73. That the new side wall would be up to and along the hipped end of the main roof, with no significant set-back from most of its edge, would emphasise the considerable scale and width of the new addition. When seen from the rear of the site and the back gardens of the adjacent properties, the new dormer would draw the eye as an overly large addition that would relate poorly to the scale and proportions of the host roof. That impression would also be evident in more distant views from [address].

The Council’s Alterations and Extensions Supplementary Planning Document (SPD) deals with roof level extensions and advises that a contemporary design is more likely to contrast successfully with the original building. The SPD also notes that rear dormer extensions should be well spaced and positioned within the existing roof slope, with a set-back of at least 0.3-metres from the edge of any hip. Within conservation areas, the SPD states that exceptional design quality must be demonstrated. It also advises that rear roof extensions will only be considered where, amongst other things, its location is set in significantly from the eaves, ridge and sides and where the dormer is no wider than two thirds of the original, unextended roof. The proposal would be at odds with this advice. [name] appreciate that the guidance within the SPD is general, and its advice does not cover every eventuality, it is, nevertheless, a relevant consideration.

From my reading of the two previous appeal decisions, a common criticism was the scale of the new dormer(s) relative to the host roof, with each Inspector concluding that the new addition(s) would appear either as a ‘noticeable top-heavy addition’ or ‘too large’. From the illustrations provided of these previous developments, the proposal would cover more of the host roof with the strong impression that it would appear to be even larger particularly with limited space alongside the hipped end. Even applying a pragmatic and reasonable approach, which the SPD advocates for schemes that fall outside the context of the SPD, the proposal would in my view be a disproportionate addition.

The extensive glazing in the new rear elevation at a high-level would also form a strident feature of the completed dwelling. The visual effect of an uninterrupted long row of large-glazed units in a prominent position would be to overwhelm the fenestration in the rear façade of the building even with the new single storey rear extension in place. This arrangement would conflict with the advice within the SPD, which states that dormer windows should be modest in size and subordinate to the building and the windows below the roof.

For all these reasons, the proposal would be an uncharacteristically large, overly dominant and obtrusive development that would detract from the character and appearance of the host building and the local area. As such, the new dormer would diminish the contribution of No 73 to the significance of the CA as a designated heritage asset and fail to preserve its character and appearance. As such, the proposal does not overcome the main concerns raised in relation to the earlier appeal schemes.

Planning policy and guidance at all levels welcomes innovative and creative design that can contribute to the diversity of an area and add visual interest to the host building. However, that policy support is qualified. The National Planning Policy Framework (the Framework) notes that it is proper to respond to local character and to promote or reinforce local distinctiveness. The advice within the SPD supports exceptional quality contemporary design, where it is sympathetic to the character of the dwelling. For the reasons given, that would not be the case with the proposal before me.

The appellant has drawn my attention to several other rear dormer extensions of modern style in the CA that are visible from the road. In my experience, it is rare that direct parallels can be drawn between one site and another because local circumstances often vary. In this instance there are significant differences in terms of location, proposals and characteristics between the various sites such that preclude meaningful comparisons with the proposal.

Specifically, the dormers at [address] and [address], which was recently approved on appeal, are on mid-terrace properties and differ in their design to the proposal. While the rear dormer at [address] is of contemporary design and it follows the hipped roof and was approved on appeal, it is roughly half the size of the proposal before me with far less glazing. When seen from [address], it is also seen along with the modern style rear dormer at [address], which is a different context to that of No

In my opinion, the style and fenestration of the rear dormer at No 62, which was designed by the project architect in this case and is referred to in the SPD, contrasts with that of the proposal. [name] have carefully considered each of these developments and their planning history, none persuade me that the proposal should therefore be allowed.

The harm caused by the new dormer extension would be localised and so the effect on the CA would be less than substantial. Even so, the Framework states that great weight should be given to the conservation of such assets, which I have done. In those circumstances, the Framework states that harm should be weighed against the public benefits. No such benefits have been put forward and none would outweigh the significant harm that I have identified.

On the main issue, I conclude that the proposed dormer would harm the character and appearance of the host building and the local area. Accordingly, it conflicts with Policy HC1 of The London Plan, Policies 15 and 16 of the [name], [name] 30, 31 and 36 of the Development Management Local Plan and the SPD. These policies and guidance aim to ensure that development achieves a high-quality design, having due regard to the importance of preserving or enhancing heritage assets. It is also at odds with the Framework which states that development should be sympathetic to local character, add to the overall qualities of an area, and conserve or enhance the historic environment.

The Council raises additional concern that the proposal, if allowed, would set an undesirable precedent for similar forms of development that could lead to an adverse effect on the character and qualities of the CA. As the appellant relies to some extent on recent planning decisions to approve rear dormers of contemporary design elsewhere in the CA, the Council’s concern is not without foundation. Nevertheless, a key planning principle is that each development should be assessed on its own planning merits, which I have done.

From my inspection of the plans, the conservation style roof lights are not clearly severable to the new dormer, which is objectionable. Therefore, I have not issued a split decision that grants planning permission solely for them. I also note that the ground floor rear extension has been approved separately.

The proposed development would conflict with the development plan. There are no material considerations, including the policies of the Framework, which indicate that the decision should be taken otherwise than in accordance with

For the reasons set out above, and having regard to all other matters raised, I therefore conclude that the appeal should be dismissed.