Appeal 6005358

The appeal is dismissed.

I am aware the proposal was revised during the planning application process as the appellant sought to address the issues being raised. For the avoidance of doubt, I have assessed the proposal on the final set of drawings on which the Council made its decision. Accordingly, I have used the description of development used on the Council’s decision notice in the header above rather than as described in the planning application form as that more accurately reflects the proposal before me.

The main issue is the effect of the proposed development on the living conditions of the neighbouring dwelling No 11 [name] with particular regard to overshadowing and whether the proposal would be overbearing.

The appeal site comprises a semi-detached dwelling. The property is adjoined by No. 11 [name] to the north and No. 9 [name] to the east. From the information before me and as observed on my site inspection, the section of the rear elevation of No. 11 closest to the appeal property contains two openings; a ground-floor window serving the kitchen and a first-floor window serving a bedroom.

The proposed extension would add an additional storey along the shared boundary for the full depth of the existing ground floor projection, with no meaningful gap or stepping back from the boundary. The resulting combination of height, length and proximity would present a substantial and dominant form that would be overbearing when viewed from the rear of No. 11 immediately adjacent to the shared boundary.

Regarding shadowing, I have carefully considered the appellant’s shadow analysis, which illustrates the extent of the impact when assessed across the year on 21 March, 21 June, and 21 December at 12:00 and 15:00. The shadow diagrams demonstrate that at 12:00 on all three dates there is no material change from the existing situation. However, by 15:00 the impact becomes clear. [name], part of the kitchen window becomes subject to shadowing. [name] this would extend across the full kitchen window. [name] the most significant impact is evident, with shadow extending across both the kitchen and first-floor bedroom windows. The evidence confirms that material harm by way of overshadowing above the existing baseline would likely be present throughout much of the year.

I, therefore, do not agree with the appellant's contention that the shadow analysis demonstrates acceptability. It also does not address the fact that the loss of daylight would occur primarily to the kitchen, and the harm in this case is materially greater than where multiple openings exist. The kitchen window on the western elevation of No. 11 is the primary source of natural light for that room and any material reduction in daylight would be likely to harm its habitability as a whole. This is not a peripheral impact but goes to the functional adequacy of a primary habitable room, and it weighs significantly against the proposal.

The appellant draws attention to No. 11 having had an extension approved with additional openings. I accept that the existing relationship must be understood in its full context, and I have considered those features as part of the established baseline. However, even taking that baseline as my starting point, the appeal proposal would materially add to the overshadowing of the rear windows above that which currently exists. The neighbour's own extension does not neutralise the additional harm identified; it simply forms the context within which it must be judged.

Finally, I have had regard to the appellant's personal circumstances, with five people including three children living in a two-bedroom property. The appellant has explained that relocating to a larger home is not financially realistic given local house prices and cost-of-living pressures. However, it is well-established that personal circumstances, while a material consideration, rarely outweigh harm to third-party amenity where that harm is unreasonable. As the harm identified in this case would be significant and permanent, the personal circumstances presented are not sufficient to outweigh the harm that would arise from the proposal to the amenity of the occupiers of No. 11.

In conclusion, Policy 12 of the Cornwall Local Plan Strategic Policies 2010-2030 (CLP) requires that development proposals protect individuals and property from overshadowing and overbearing impacts. For the reasons set out above, the proposed extension would fail to do so. The material reduction in daylight to the rear windows of No. 11 serving habitable rooms, and the overbearing impact arising from the height, length and proximity of the extension to the shared boundary, are each contrary to Policies 1 and 12 of the CLP and paragraph 135 of the National Planning Policy Framework, which seek to deliver sustainable development that protects the amenity of existing and future users.

The external materials including composite cladding and UPVC windows represent a modernised palette that, while contrasting with the traditional rendered masonry of the host dwelling, would not be a reason to refuse planning permission. Acceptable design is, however, a requirement for any development and consequently does not outweigh the harm identified.

For the reasons set out above, the proposal is not in accordance with the development plan, and there are no material considerations that outweigh this conflict. Accordingly, the appeal is dismissed.