Appeal 3311707

The appeal is dismissed.

The appeal form confirms the description of development was changed from that appearing on the application form and that this was agreed with the LPA; that description being the basis of this decision.

The main issue is the effect of the proposed development upon the character and appearance of the host dwelling and the surrounding area.

The appeal site, [site address] (No.129) is an extended semi-detached house in a well-established area of suburban housing dating from the mid-twentieth-century with a two-storey side extension and single storey part-width rear extension. Due to the underlying topography, No.[address] level but also significantly higher than its rear garden which slopes down from the house such that main ground floor rooms access the garden by a stairway from a small, elevated terrace giving a prominent outlook to the rear which, in my assessment, would also be enjoyed from other rear facing windows on its upper floors.

The proposal would combine a hip to gable extension and a full width rear dormer for new second floor level accommodation. Although the hip to gable extension would change the external appearance of the dwelling in the street, such alterations are present on a number of other properties in [address] including No.127, and an additional such change would not be obtrusive in the street scene.

The appellant has provided several examples of similar roof alterations on dwelling pairs including those which lead to an unbalanced appearance within a dwelling pair in [address] where the topography is similar at the rear of the odd-numbered houses. The appellant, by reference to an appeal decision1 at [address], points to the importance of contextual considerations in appeal decisions, in that case as justification for divergence from guidance as to the changes proposed. However, the policies and guidance relevant to the matter to be determined both vary according to the matters of each case and, as here, may go beyond consideration of impact on street scene but also to the effect of the proposals in other terms, and it is those matters to which I now turn.

The Barnet Residential Design Guidance SPD (2016) 2 (Design Guidance) identifies the capacity for ‘profound effects on the appearance of the area and on the amenities enjoyed by the occupiers of adjoining properties’ as a consequence of individual and cumulative extension. The guidance gives six examples of unacceptable impacts upon amenity including a ‘sense of enclosure or overbearing impact’; and also sets out ways in which extensions can harmonise with the host building.

The paired dwelling to No.129, [address] (No.131), is a substantially original dwelling which, unusually, sits slightly lower than No.129; the garden falls away from the property with a terrace at the rear of the house and several steps down to the garden area. Whilst the outlook from the terrace is southerly, there are substantial trees to the south and west both within and outwith the curtilage of No.131 such that its grassed amenity area feels enclosed and shaded. There is also a high screen at the eastern end of the terrace on the boundary with No.129, adding to a sense of enclosure although this would not diminish the overbearing effect of the proposed dormer.

In a full submission of precedents, the appellant points to the consistency of the proposal with aspects of the adjacent dwelling pair referred to in the appellant submission3. No.[address] (No.125) has four rear-facing levels of accommodation including what appears to be a basement area under a terrace. Its paired dwelling, No.127, is of broadly equivalent height despite the absence of a basement level, and also presents a significant number of windows at upper floor levels. These dwellings are very much larger than they would have been originally, extended to full width of their plots and with additional levels of accommodation.

Whilst it is in the nature of suburban housing development that a degree of overlooking of neighbours’ amenity space will take place and that living in such locations presumes amenity spaces will not be entirely private, by and large the acceptability of such relationships arises from a perception of equivalence between neighbouring users; properties of similar height, mass and intensity of use or occupancy.

The appellant suggests the proposed development would be of similar height and bulk to the dwelling pair on the eastern side of the appeal site, but that would not be the case with its adjoining dwelling to the west, No.13, which is a two-storey family home, apparently in its original form. The addition of an 1 N5090/D/21/3282358 2 At section 14 3 Nos 125 and [address] extra floor level at No.129 would increase the existing sense of enclosure and create an overbearing effect on users of the adjoining terrace at No.129 due to the additional height and mass at roof level. In addition the perception of overbearing height would be amplified by the low ground level of the associated garden and the proposed increased height of the ridge.

Overall, the proposed development, by virtue of the height of a large full width dormer and the introduction of habitable accommodation at roof level, would be unacceptably overbearing on its paired dwelling and its rear amenity spaces. This would be in conflict with Policies CS1 and CS5 of the [name]: [name] (2012), Policy DM01 of the [name]: Development Management Policies DPD (2012) and the Residential Design Guidance SPD (2016).

[name] have found there would be no significant harm to the character and appearance of the street scene from the hip to gable extension or the insertion of rooflights, this does not outweigh the harm I have identified to the amenity of neighbouring users. The proposal would fail to accord with the development plan taken as a whole and on that basis the appeal fails.