Appeal 3293086

The appeal is dismissed.

The main issue in the appeal is the effect of the proposed dormer structure on the character and appearance of the host dwelling, the [address] Conservation Area and the setting of a listed building.

[address] is situated on the east side of [address] within the [address] Conservation Area. It is attached to [name] to its north and both residential properties are locally listed buildings and therefore non-designated heritage assets. [address] is the dwelling to the south and its neighbour to the south is Miramonte. The latter is a grade II listed building (in 2 parts) in the [name] style.

[name] has a wide dormer structure on part of its front roof facing [address].

The proposal is to insert a single dormer structure into the rear roof of the southern main element of [address]. (There is a single storey conservatory on its southern flank wall.) The proposed dormer would replace an existing offset small dormer with a flat roof. It would have two windows which would be broadly aligned with the ground floor window and ground floor doors below.

In principle dormer windows in the roof which is the subject of the appeal are acceptable, however, the proposed dormer would be a significant size which would take up a very large proportion of the roofslope. Whilst acknowledging that it would sit down from the roof ridge and be slightly slimmer in width than the width of the roofslope, it would sit just above the eaves and its overall scale and box-like design would give a top heavy and unbalanced appearance to this southern section of [address]. It would be significantly more prominent than the existing discreet dormer in the rear roof. It would harm the significance of the non-designated heritage asset by detracting from the visual coherence of [address] when viewed as a whole from the rear.

Turning to the [address] Conservation Area, its significance and special architectural and historic interest is neatly summarised in the designation as being the core of the demolished 16th century [address] manorial estate, including walls, outbuildings, and landscape features from the 17th, 18th and 19th centuries, together with 20th century infill developments. [address], was located at the southwest corner of the intersection of present-day [address] and [address]. Its red brick boundary walls can still be seen on the west side of [address]. Remains of the 16th century mansion include all stretches of the high brick walls on [address], and [address]; the listed stretch of wall on [address]; and the two storey cottage incorporated into [address].

I am mindful of the duty on me pursuant to section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 to pay special attention to the desirability of preserving or enhancing the character or appearance of the Conservation Area. There would be limited views of the proposed development from the public domain but private views of a conservation area are also of importance and I have borne both public and private views in mind. I consider there would some harm to the conservation area because of the scale and design of this dormer structure. That harm would be less than substantial in terms of paragraph 202 of the National Planning Policy Framework and the harm would be at the low end of the spectrum of harm. Some benefits would flow from having increased residential accommodation in the Borough and also from the economic benefits flowing from the construction works. Nevertheless, in terms of paragraph 202 of the Framework, the less than substantial harm is not outweighed by the benefits.

Turning to the issue of impact on the setting of the listed building, I have the section 66 duty in mind. I consider that the setting of Miramonte would be detrimentally affected as views out of it would be likely to include at least a partial view of the proposed large dormer. The setting of the listed building would not be preserved or enhanced for this reason. Even if the setting was not affected, the other harms in this case are sufficient in my view to warrant refusal of planning permission. 10.I conclude that the proposal would harm the character and appearance of the locally-listed host dwelling by reason of its scale and design. It would also fail to preserve the character and appearance of the [address] Conservation Area and would fail to preserve the setting of the listed building Miramonte. It would be contrary to policy D3 of the London Plan 2021, policies CS8, DM10 and DM12 of the [name] (adopted 2012), and PG39 of the Residential Design Supplementary Planning Document (2013).