Appeal 3345488

The appeal is dismissed.

The first main issue is the effect of the proposal on the character and appearance of the host dwelling and the surrounding area. The second main issue is the effect of the proposal on the living conditions of the occupiers of [address] (No.54), with particular regard to visual impact.

[address] is predominantly characterised by traditionally designed semi-detached and terraced family sized dwellings occupying generous sized plots. The uniformly designed dwellings typically have white rendered walls under fully hipped plain tiled pitched roofs. On the front elevations the semi-detached dwellings have matching two storey projecting bay windows and projections with matching hipped, gable or flat roofs. Some of the dwellings have porch, hip to gable extensions and a variety of side extensions, although the overall sense of uniformity is retained.

To the rear the dwellings were originally designed with flat rear elevations, although a significant proportion now have single storey rear extensions of various sizes and with flat or shallow pitched roofs. A number of the dwellings also have two storey rear extensions and loft conversions and within the rear gardens there are a diverse range of garages and outbuildings. Notwithstanding these changes, the overall character of the dwellings and the rear garden environment is traditional and verdant.

To the rear of the appeal dwelling is a part pitched and part flat roofed extension which abuts a smaller rear extension at the rear of No.54. Just beyond the appeal dwelling is an attached garage that projects up to the boundary with [address] (No.50) and towards the rear of the garden is a large contemporary outbuilding whose roof overhang spans most of the width of the garden.

Together and amongst other things policies 6 & 37 of the London Borough of Bromley Local Development Framework Local Plan 2019 (LP) and Policy DG5 of the London Borough of [name] 2023 (USPD), expect new development to be of a high standard of design and layout. Development should respect or complement the scale, proportion, form, layout and materials of host and adjacent buildings. Extensions should respond to the character and appear subservient in scale of the existing dwelling and should respect the amenities of the occupiers of neighbouring buildings. Paragraph 135 c) of the National Planning Policy Framework states that new development should be sympathetic to local character and history, including the built environment and landscape setting, while not preventing or discouraging appropriate innovation or change.

Reference has also been made to LP policies 7, 8, 26, 115, 123 & 124, which relate to various aspects of design. Collectively and amongst other things they require domestic extensions to be in keeping with the design and scale of the existing house; support physical and mental health; seek to reduce flood risk; and support sustainable design and construction and a reduction in carbon emissions. USPD Policy DG1c) seeks to preserve and enhance the positive aspects of Bromley’s unique character by referencing and taking cues from the surrounding context to inform appropriate architectural language which is sympathetic and responsive to existing and emerging context.

With the proposal the existing rear extension and attached garage would be demolished and would be replaced with a six metre deep single storey extension. It would project up to the boundary with No.54 and span the width of the dwelling. It would be contemporary in appearance and design with vertical zinc clad walls and a curved zinc clad roof. The roof would overhang the rear of the extension and would include two small roof dormers, similarly with curved zinc clad cheeks and roofs.

A gap would be maintained between the proposed extension and the existing extension at No.54 and at this point the roof of the proposed extension would be noticeably taller than that of the extension at No.54. The curved dormer roofs would rise above the tallest point of the main roof of the extension and the sill height of the rear first floor window. The roof design and overhangs together with the use of aluminium sheeting on the proposed extension’s walls and roof would emphasise the mass, form and height of the proposed extension.

As a result of these factors the proposed extension would dominate and appear totally out of context with the host dwelling. Whilst large and contemporary extensions can and often do complement and enhance the appearance of buildings, due to its collective form, detailing and extensive use of aluminium sheeting the effect of the proposed extension would be dominant and jarring rather than complementary to the host building. This harm would outweigh the benefits for the appellant and their family that would result from the proposed additional and energy efficient living accommodation.

Due to its use of extensive areas of glazing and timber, I agree that the contemporary designed outbuilding does take cues from its rear garden environment in terms of materials, views and vertical lines. However, it is located away from the dwelling, where it has its own identity within the rear garden environment. Its design and use of timber are also distinct from the proposed extension. Conversely, the proposed extension would be out of context and would fail to respect or complement the host dwelling and the rear garden environment.

I note the comments made by the appellant regarding a number of dwellings in the locality with six metre deep rear extensions and the availability of permitted development rights. However, in this instance my concerns relate to the proposal’s form, design, materials and appearance rather than its footprint.

Finally, whilst in principle the location and footprint of the proposed bin store appear reasonable, without elevational details I am unable to make a full assessment of their impact.

For these reasons I conclude on the first main issue that the proposal would unacceptably harm the character and appearance of the host dwelling and the surrounding area. It would conflict with [name] 6 & 37, USPD Policy DG5 and paragraph 135 c) of the Framework.

The proposed extension would be some 3.4 metres tall, excluding the proposed raised concrete pavers. Including its roof overhang it would project some 3.6 metres beyond the rear building line of the adjacent extension at No.54. Notwithstanding the bamboo placed in planters along the adjacent boundary within the garden of No.54, due to its combined height, overhang depth, design and materials the proposed extension would appear prominent and stark in the outlook from the adjacent ground floor living room and rear patio area at No.74. It would similarly appear as a stark and discordant feature in the outlook from the rear garden of No.54.

For these reasons, I conclude on the second main issue that the proposal would unacceptably harm the living conditions of the occupiers of No.54, due to its visual impact. Accordingly, the proposal would conflict with LP Policy 37e).

Whilst reference has been made to the installation of an air source heat pump there is no reference to one in the application form or on any of the drawings. Notwithstanding this the installation of any external heating or air conditioning apparatus could be satisfactorily dealt with by condition.

Concern has been raised about the stability of the garage at No.70, which is attached to the garage which would be removed. This is a private matter that falls outside the scope of this application, although is something that could to be addressed under other legislation.

[name] have found in favour of the appellant on some matters the conclusions on the main issues amount to compelling reasons for dismissing this appeal, which the imposition of conditions would not satisfactorily address.