Appeal 3300835

The appeal is dismissed.

The main issues are the effect of the proposed development on: • living conditions of adjoining users and • the character and appearance of the area.

The appeal site (No. [site address] ) is located on [site address] , a wide highway lined with mid-twentieth century suburban housing set, generally, in large plots. No. [site address] , however, is located close to close to the junction with [address] where housing on both roads converges such that the neighbouring property, No.168, is placed within a triangular plot of land allowing only limited rear garden. Although these gardens generally enjoy a southerly aspect towards mature trees, a further constraint is that ground levels fall sharply away from the road such that the ground storey of these properties, with its semi-detached pair No.172, sit significantly higher than the rear garden. The resulting stepped accesses with terraces contribute to a generally disconnected relationship between habitable internal space and the respective dwellings’ outdoor amenity areas.

The proposal seeks to address this by a two-storey rear extension for the width of the house with the upper storey projected from the main ground floor of the dwelling and its lower storey partly set into the existing ground but providing access to the garden as an additional, partial, basement level.

The appellant points to the basement nature of the lower storey of the proposed extension and the screening provided by boundary hedging with No.172 although it is not clear how this would be retained. The impact on use of the outdoor spaces immediately adjacent to the rear of No.172 and No.168 would be broadly consistent with that of a single storey extension of No. [site address] . However, my observations indicate that, due to the 6m projection of the proposal, and based on the information provided, the resulting height of the rear elevation relative to natural ground level would not be less than 4.5m, the impact of which would approach that of a two-storey rear extension when viewed from within the adjoining gardens.

The flank wall of the proposed extension would be prominent and, due to its relative height, overshadow a significant proportion of the small rear garden of No.168 to a degree which I consider would be unacceptably overbearing. This would make the use of this modest amenity area less attractive notwithstanding its orientation. Although the overshadowing of the outdoor amenity space of No.172 would be less significant than this, the extension would be plainly apparent above the existing boundary hedge line (if retained) and unacceptably prominent in the extent of built form along the shared boundary.

Notwithstanding difficulties presented by topography, the rear garden areas of these dwellings provide a pleasant setting for adjoining occupiers to enjoy. The extent of projection from the main body of the house at an overbearing height, having little equivalence with a ground-level single storey extension, would significantly impair this amenity. I therefore conclude the proposal would conflict with Policy DM1 of the Harrow Development Management Policies Local Plan (2013) (DMPLP) and with policy D3.D(7) of The London Plan (2021) which together highlight the importance of good design to retaining high standards of amenity and seek to protect privacy and amenity.

No. [site address] and its neighbours exhibit, as with large swathes of inter-war suburban housing, residual ‘Arts and Crafts’ characteristics such as the extensive pitched tiled roof which draws down to lower eaves, with accommodation within the roof void to reduce the apparent bulk of the dwelling. This characteristic is evident in the rear elevation in the dropped eaves and dormer arrangement at the rear such that the flat roof of the proposed extension would appear to be disproportionately close to the eaves of the main roof.

The appellant suggests the contribution of the property to local character and context is principally in terms of views from the street. Although the extension would not impinge upon the street scene due to the limited opportunities to discern its presence from street level, and whilst ground floor rear extensions may have limited visual impact where ground levels are consistent, that is not the case here. The appellant has demonstrated the effect of the extension being partly sunken below garden level, however this does not, to my mind, alter the significant visual impact of what is proposed. The development would appear as a disproportionately bulky addition almost two storeys in height projecting a significant distance from, and substantially concealing due to the lower garden viewpoint, the original rear elevation. The proposal would thereby dramatically change the form and pattern of the housing group, and visually unbalance the housing pair. This would be detrimental to local character and appearance and conflict with Policy DM1.B of DMPLP and with Policy CS1.B of the [name] (2012) which together seek to achieve a high standard of development that protects visual amenity and local character. 10.Overall, taking all matters raised into account and for the reasons given, I conclude that the proposal would conflict with the development plan as a whole and, in consequence, the appeal cannot succeed.