Appeal 6007039

The appeal is dismissed.

The main issue is the effect of the proposed development on the character and appearance of the host dwelling and wider area.

The appeal site comprises a two-storey semi-detached dwelling on a corner plot at the junction of [address] and [address]. The property forms a semi-detached pair with No. [address] (No. 14) to the south. The surrounding area is characterised by residential development of a broadly consistent character, comprising predominantly semi-detached dwellinghouses.

The proposed side extension would have a width of around 5.5 metres, which is close in size to the 6.3 metre width of the host dwelling. Its roof would be set down by only 0.25 metres and set back by only 0.7 metres from the principal elevation. Taken together, the bulk and scale would result in an overly large and dominant addition that lacks subservience to the host property. Moreover, whilst the proposed height broadly reflects the eaves and ridge of the host dwelling, the corner plot position means the extension would be visible from two street frontages. This compounds the effect of the width and insufficient set-back, resulting in a built form that would dominate the junction rather than receding from it.

The consistent pattern of corner dwellings in the immediate locality is one of maintaining a meaningful separation from the secondary street frontage. The reduction from approximately 7.36 metres to approximately 1.8 metres in this case would depart significantly from that established pattern and would result in an overdevelopment of the corner plot harming the street scene of both [address] and [address]. The corner plot's generous dimensions and the fact that the extension would stop 1.8m short of the side boundary therefore do not justify the excessive scale and width proposed.

Regarding symmetry, whilst I acknowledge that existing development at No. 14 has altered the symmetry of the semi-detached pair, that extension is single storey and of significantly lesser bulk and as such provides no justification for the excessive scale proposed here. The appellant also contends that the proposal cannot be mistaken for a separate dwelling as it introduces no separate access or independent curtilage, and I accept that no additional unit would be created. However, the near-equivalent width combined with the modest set-back and minimal ridge set-down would cause the semi-detached pair to read from the street as three terraced units, which would appear notably out of keeping with an area characterised predominantly by semi-detached pairs.

[name] agree with the appellant that Supplementary Planning Document 2 (SPD2) carries less weight than adopted development plan policy and acknowledge that other two-storey extensions in the street do not all strictly comply with its suggested dimensions, it nonetheless provides helpful guidance on achieving visual subservience. However, a set-back of only 0.7 metres and a ridge set-down of only 0.25 metres are modest figures in the context of an extension measuring 5.5 metres in width, with the combined effect that the extension reads as a near-continuous enlargement rather than a visually proportionate addition that SPD2 seeks to achieve. The appellant's functional justification for the 0.7 metre set-back does not alter my assessment of its visual effect from the street; if the internal layout cannot accommodate a greater set-back in order to comply with the development plan, that is a constraint that weighs against the proposal rather than in its favour.

The appellant has highlighted several nearby properties with two-storey side extensions, including Nos. 22, 24, 26, 33 and [address] and others on [address]; I accept that such extensions are not wholly alien to the street. However, each case must be assessed on its own merits. The other examples are distinguishable as they are narrower relative to their host dwelling or achieve greater set-back or ridge set-down, and most do not occupy a prominent corner position visible from two street frontages. No. [address] occupies a corner plot but the information before me does not demonstrate that it presents the same combination of scale, massing and visual impact. The curtilage comparison presented therefore does not assist, as the harm identified relates to the overall visual impact from the street rather than solely to the loss of open land.

I also acknowledge, supported by aerial imagery from 1999 and 2024, that the street has evolved through incremental enlargement and that proposals must be assessed against the area as it exists today rather than its historic baseline. On that basis, I find that the extensions characterising the current streetscape are, as a whole, of lesser scale and greater visual subservience relative to their host dwellings than the proposal before me. The evolution of the street does not therefore raise the threshold of acceptability to the point where this proposal would sit comfortably within it.

Furthermore, the proposed windows at both ground and first floor level would introduce a functional design that sits awkwardly alongside the inter-war character of the host property and wider street. Whilst the appellant contends that this was a deliberate design choice intended to avoid competing with the host dwelling's two-storey bay window, I do not find this reasoning persuasive. The design objective of subordinating the extension to the original dwelling could have been achieved through fenestration that better references the proportions and character of the existing windows without replicating the bay form, and the failure to do so represents a further way in which the extension does not successfully integrate with its host property or wider context.

The Council acknowledged that a revised single-storey rear extension may have been acceptable in isolation. However, the rear extension and two-storey side extension form a single scheme that must be assessed as a whole. As such and having found the two-storey side extension unacceptable, the rear extension cannot be considered in isolation.

For the reasons given, I have found that the proposal would cause demonstrable harm to the character and appearance of the host dwelling and the wider street scene by reason of the two-storey side extension's excessive scale and massing relative to the host dwelling, its insufficient set-back and ridge set-down, and its incongruous frontage window fenestration. Accordingly, the proposal is contrary to Policy BCS21 of the [name] 2011 and Policies DM26, DM27 and DM30 of the Site Allocations and Development Management Policies 2014 and the relevant guidance in SPD2. The proposal also conflicts with Paragraph 135 of the National Planning Policy Framework, which requires development to be sympathetic to local character.

I acknowledge the points in the appellant's favour, including the corner plot context, the evolved street character, the established asymmetry at No. 14, the matching materials, and the absence of amenity, highway or heritage harm or objections. I have weighed these carefully. However, the harm identified from excessive scale, insufficient set-back and ridge set-down, incongruous fenestration, and erosion of an open corner visible from two frontages is demonstrable and specific rather than subjective or marginal. This is sufficient to justify refusal notwithstanding the Framework's presumption in favour of sustainable development.

I have had regard to the demolition of an existing three-metre lean-to, reducing the net additional footprint, but the harm identified relates principally to the scale and massing of the two-storey side extension as it would appear from the street.

I have also weighed the benefits of the proposal, including the provision of additional family accommodation and efficient use of existing land and infrastructure, but find that these do not outweigh the harm identified to the character and appearance of the host dwelling and wider street scene.

For the reasons given and considering all matters raised, I conclude that the proposed development does not accord with the development plan and the appeal is dismissed.