Appeal 6007896

The appeal is dismissed.

The description of development in the banner heading above is taken from the Council’s decision notice. I consider that this description more precisely describes the development which is the subject of this decision.

The main issue is the effect of the proposed second floor side extension on the character and appearance of the host dwelling and the surrounding area.

The appeal property comprises a detached dwelling situated within an established residential area. The dwelling occupies a prominent position within the street scene and has been constructed in a contemporary style characterised by a steeply pitched front gable, cylindrical stair tower, extensive areas of glazing and contrasting external materials. The property is visually assertive and differs materially in architectural form and appearance from the surrounding dwellings.

The surrounding area is characterised by a varied pattern of development including detached and semi-detached dwellings of differing ages, scales and architectural styles. Whilst there is some commonality in terms of general residential character and building heights, the streetscene is eclectic in appearance with differing roof forms, materials, architectural detailing and plot arrangements evident throughout the area.

Despite this variety, I observed during my site visit that the appeal property presently retains a coherent architectural form. In particular, the principal front gable remains the dominant feature of the dwelling, with the cylindrical stair tower and other elements appearing visually secondary within the overall composition of the building.

The proposal includes the removal of the existing roof terrace and the erection of a second floor side extension above the existing cylindrical stair tower. The extension would continue the side elevation upwards and tie into the existing gable roof form utilising matching materials and additional window openings.

I acknowledge that the appeal property is already architecturally distinctive and that the proposal seeks to use similar materials, glazing and design features to those already present within the building. I also recognise that the surrounding area contains a variety of architectural forms and styles and is not characterised by a uniform or especially sensitive streetscene.

However, I consider the existing building presently derives much of its coherence from the relationship between the principal front gable, the cylindrical stair tower and the lower side element with terrace above. The existing arrangement allows these different elements to remain visually separate and balanced within the overall composition of the building.

The proposal would materially alter that relationship. By extending the side element upwards and tying it directly into the main roof form, the proposal would substantially increase the amount of built form at this upper-level and create a more congested roof form. The side element would begin to compete visually with the principal front gable and the cylindrical stair tower would lose much of its current visual role within the appearance of the dwelling.

I also consider that the proposal would introduce an accumulation of competing forms and glazing arrangements. These collectively would diminish the coherence and balance of the existing dwelling, appearing overly assertive and poorly resolved when viewed from both the front and side of the property.

The appellant suggests there is opportunity to accumulate domestic paraphernalia on the roof terrace, creating a cluttered appearance. However, I do not consider the existing roof terrace to be inherently harmful to the appearance of the building or streetscene, and therefore the proposed removal of the roof terrace would not justify the harms identified above.

I have considered the appellant’s submissions regarding the broad nature of the adopted and emerging design policies and the lack of supplementary design guidance relating to domestic extensions. Nevertheless, policies relating to design are in place and, when read alongside the provisions of the National Planning Policy Framework (the Framework), provide an adequate policy basis against which proposals can be assessed.

In this instance, and for the reasons outlined above, I do not consider the proposal would be a successful addition to the existing dwelling. I find that the additional upper-level built form would harm the overall balance and composition of the building to the detriment of both the dwelling itself and the wider street scene. Whilst the surrounding area contains varied architectural styles, the appeal property occupies a prominent position and remains highly visible within the street scene. Consequently, harm to the architectural composition of the dwelling would also result in harm to the wider visual amenities of the area.

Emerging Portsmouth Plan (July 2024) Policy PLP1, 2a, b and c seek the creation of memorable, distinctive and attractive buildings and, in this regard, is consistent with the Framework which seeks the creation of high quality, beautiful buildings. The proposal would fail to achieve these requirements.

For the reasons set out above, the proposal would conflict with Policy PCS23 of the Portsmouth Plan, which requires development be of excellent architectural quality.

For the reasons outlined above, and taking into account all other matters raised, I conclude that the appeal should be dismissed.