Appeal 3355672

The appeal is dismissed.

Since the appeal was lodged the National Planning Policy Framework (the Framework) has been updated. I am satisfied there are no changes of any consequence for the main issue in this appeal.

Notwithstanding the description of development set out above, which is taken from the application form, it is clear from the plans and accompanying details that the development comprises the addition of a dormer window to the side roof slope, a dormer extension to the rear roof slope and 2 rooflights to the front roof slope. The Council dealt with the proposal on this basis and so shall I.

The main issue is whether the proposed development would preserve or enhance the character or appearance of the [address] Conservation Area (the Conservation Area).

As the appeal site is within a conservation area, I have a statutory duty under Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act) to pay special attention to the desirability of preserving or enhancing the character or appearance of the area. The Framework also requires great weight should be given to the conservation of heritage assets. These include conservation areas.

I have drawn my description of the relevant aspects and heritage significance of the Conservation Area below from the [address] Conservation Area Character Appraisal, March 2008. Observations during my site visit confirm the appraisal.

The Conservation Area encompasses an early example of planned housing in a suburban location developed during the late 19th- and early 20th-centuries. Much of the heritage significance, character and appearance of the area derives from the survival of a consistent pattern of buildings with high-quality architectural detailing, design and materials.

Domestic buildings in the area, and along [address], are in a variety of styles and materials. However, the area is characterised by 3 predominant domestic building types developed in 2 phases. The late 19th-century phase of development predominantly includes three-storey detached villas and three-storey semi-detached villas, as seen adjacent to the appeal property. The early 20th-century phase of development principally includes two-storey terraced rows. The appeal property is an end terraced dwelling in the only terraced row constructed on [address]. While there is variety in form, scale and materials along the street, the pattern of development is consistent, harmonious and complementary.

Dormer windows are present on the side and front roof slopes of several detached and semi-detached properties along the street. However, these are predominantly original elements of the buildings. Dormer windows are not an element of the terraced row. Apart from the two-storey extension to the rear of the host property, and several rooflights along the rear plane of the terrace roof, the terraced row is largely unchanged. While the two-storey extension alters the symmetry of the rear elevation of the terraced row it complements the architectural language, massing and materials of the terrace and remains subordinate to the form of the original development. As such, the original form, proportions and architecture of the host building and terraced row remain legible.

The proposed rear dormer extension would be sited above and to one side of the two-storey extension to the host property. The rear dormer extension would add mass to the upper level of the rear elevation of the host property. The windows of the rear dormer extension do not align with the existing fenestration below it. Furthermore, the proposed rear dormer extension would be constructed against the feature party wall and chimney between the host property and neighbouring dwelling. As such, the rear dormer extension would appear unbalanced and cluttered harming the proportions and appearance of the host building and terraced row. The visual prominence and legibility of existing architectural features would be harmed by the scale, mass and siting of the rear dormer extension. While visibility of the rear dormer extension from the public realm would be limited it would be a prominent feature at roof level from the gardens and upper floor windows of several dwellings in the surrounding area.

The design of the proposed side dormer window reflects the dormer window in the roof of the adjacent semi-detached villa in both form and materials. As noted above, the neighbouring dwelling dates from the earlier phase of development in the area and employs a different architectural language. As such, the proposed side dormer window would be both out of context and a departure from the otherwise consistent and unaltered roof of the terraced row. The proposed side dormer window would be located centrally between 2 prominent chimneys. The chimneys, matched by a pair at the other end of the terrace, bracket and terminate the roofline of the terrace. Rather than being partially concealed behind one of the chimneys, as suggested by the appellant, the proposed side dormer window would be a prominent feature that would disrupt the form and symmetry of the roofline, as seen from the street, and challenge the prominence of the chimneys. This would harm the visual and historical significance of the building and the stylistic juxtaposition with the adjacent building.

Both the rear dormer extension and side dormer window fail to respond sensitively to the architectural language and proportions of the host dwelling, terraced row and other buildings when seen together. Therefore, the proposal, by nature of its form, massing and siting, would fail to preserve or enhance the character or appearance of the host dwelling and surrounding area and would result in less than substantial harm to the heritage significance of the conservation area.

Notwithstanding the use of matching materials, the proposal would introduce incongruous features to the host dwelling and terraced row. The appellant suggests that the details of materials to be used could be made the subject of a condition of permission. However, in this case the materials to be used make no difference to my overall conclusion considering the harm identified above.

Paragraph 215 of the Framework states that less than substantial harm to the significance of a designated heritage asset (in this case the conservation area) should be weighed against the public benefits of the proposed development. I acknowledge the proposal would provide additional space that would benefit occupants of the dwelling. However, this is not a public benefit of sufficient weight to justify the harm identified above. I also acknowledge the appellant’s reference to the contribution the development would make toward the local economy, their personal circumstances and desire to remain within the community, and subsequent community cohesion. However, such benefits do not outweigh the harm to the Conservation Area.

I note the Council’s Alterations and Extensions Supplementary Planning Document (2019) (SPD) provides specific guidance on dormer and roof extensions in conservation areas. This includes guidance on, not only the siting of dormers within a roof slope, but also the need to have regard for the existing architectural language of the building and features of architectural interest, such as, chimneys and other windows. The appellant refers to the SPD with regard to the general principles and locational requirements for dormer windows and extensions. However, application of the general principles makes no difference to my overall conclusion when considering the proposal in the context of the conservation area and the specific harm identified above.

Taking all the above into account, I conclude that the proposed dormer extension and dormer window would neither preserve nor enhance the character or appearance of the [address] Conservation Area. They would fail to satisfy the Planning (Listed Buildings and Conservation Areas) Act 1990 in this regard and the historic environment policies of the Framework. Hence it would conflict with Policies 30, 31 and 36 of the Lewisham Development Management Local Plan, 2014, and Policies 15 and 16 of the [name], 2011, and Policy HC1 of The London Plan – The Spatial Development Strategy for [name], March 2021. Together these seek to ensure that development proposals are of a high standard of design that respond sensitively to their context, respect the form, setting, period and architectural character and detailing of the original building, and preserve or enhance heritage assets.

For the reasons given above the appeal is dismissed.