Appeal 3335873

The appeal is dismissed.

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

[address] is a wide, tree-lined, residential street. The appeal site is, like its already-extended neighbours, a substantial detached house in a wide plot. No. [site address] (No.14) is a mid-twentieth-century house of two storeys with hipped plain-tiled roof surfaces and, to its front elevation, a pair of projecting bays1 each side of a tall entrance bay which expresses its focal purpose through its height, steeper pitch roofing than elsewhere, and an architectural treatment emblematic of ‘arts and crafts’ influences2, such as the fenestration pattern with applied timber decoration (and shutters) together with deep eaves set at window head and prominent brick chimneys.

The appellant points to what has been previously-approved, a forward extension of the central front bay with amendments to the fenestration together with a full-width, deep, single-storey rear extension. However, to this, the proposal would introduce a full level of accommodation within a raised roof structure. It is to the effects of this I now turn, noting that Barnet’s Local Plan Residential Design Guidance SPD (SPD) points to the importance of scale, massing and roof 1 Which are mirrored in the rear elevation. 2 The appellant appears to agree with this characterisation, however ‘mansard’ roof forms (which the proposal might be described as introducing) are largely absent from ‘arts and crafts’ origins, but arising from ‘Baroque’ or architecture of mid-late C19 French influence. form where these reflect local character also to pitches and factors such as eaves detailing being fundamental to a proposal’s impact on its local character.

Additional accommodation would be generated within a new roof structure encompassed by a perimeter of steeply-sloping roof surfaces under a wide crown roof. The steepened pitch3 of these roof surfaces would align with that of the central front gable, however this element of the roof currently stands as a focal articulation in contrast with the passive character of main roof form which sits at a more typical 45 degree pitch. The appellant suggests that the ‘resultant front gable would still be smaller than the two proposed wings of the property as seen from the front, ensuring this part of the development does not dominate’. Whilst some elements of the proposal have received prior approval, the very significant increase in the height of the main roof and steep enclosing roof pitches, combined with the overall bulk, would subordinate what was originally a key element of the original design in terms of its height and focal presentation to the street.

Taken with the infilling of set-back to the central gable, the introduction of four dormers and eight rooflights each of a size suitable for habitable rooms rather than smaller rooflights that might be suitable for ancillary spaces (including two prominently placed on the front elevation) would give No.14 a contrived ‘mansard’ roof form. The resulting increased volume of roof, proposed to incorporate some four habitable rooms and a bathroom with access staircase, would be perceived from streetscene viewpoints as having some equivalence to the size of the floors beneath. The result would be a dwellinghouse with many of the visual characteristics of flatted accommodation, entirely different to the usual tiered hierarchy of spaces typically found in large single dwellinghouses, with ‘attic’ or secondary spaces above more substantial accommodation.

The appellant points to significant alterations to neighbouring properties, however the case is not made that these properties previously made a distinctive individual contribution to the street scene, as, from my observation, is the case with No.14 for the reasons set out, and which would be lost as a result of what is proposed. Overall, the additional height, bulky volume of the proposed roof form would introduce a degree of change to No.14 incompatible with its current distinctive contribution to the street scene and the settled character of [address] as a residential street of substantial, individual, dwellinghouses. The proposal would therefore conflict with Policy CS5 of the Barnet Local Plan ([name]) DPD (2012) and Policy DM01 of the Barnet Local Plan (Development Management Policies) DPD (2012), which, together with the Residential Design Guidance SPD seek to ensure development respects distinctive local character and incorporates high quality design. Therefore, for the reasons given and taking all matters raised into account, the appeal cannot succeed.