Appeal 3321250

The appeal is dismissed.

The main issue is the effect on the character and appearance of the area.

The proposal would result in a hip to gable roof extension. The attached property has already had such a change in roof form so the proposal would result in these semi-detached properties returning to having a matching appearance. Such a change is also common within this area. The existing side extension would be modified to accommodate this new roof form. It is set well back from the frontage and would continue to appear as a subordinate addition which has only a limited prominence in the street scene. The design and form of these two elements would result in an overall composition that would remain in keeping with the existing character and appearance of this area.

The proposal includes a rear dormer which would be a relatively large structure, set centrally within the new roof form. The plans show that the roof of the existing rear two storey extension would be modified to include a lower ridge and a shallower pitch. The plans are not consistent with regard to how these two elements would combine. The elevations show the extension roof connecting with the rear face of the dormer although this arrangement would also require that the roof of the extension wrap around the dormer to accommodate it being hipped into the roof, which is not shown. The roof plan shows the rear extension not hipping into the rear roof slope which would result in it standing proud of the roof which would represent an entirely unsatisfactory roof form. This relationship is not fully resolved as neither the www.planningportal.gov.uk/planninginspectorate Appeal Decision: APP/M5450/D/23/3321250 plans nor the elevations demonstrate the arrangements for such a juxtaposition.

As it is not clear how the relationship between the dormer and the rear extension would be completed, the plans would not form a suitable basis for a planning permission. Whilst revisions to the plans could be required by condition, it is not clear that this relationship could be suitably resolved with the scale of the rear dormer proposed. On the basis of the information available, the relationship between the rear extension and the dormer window would represent poor design. It would conflict with paragraph 6.71 of the Supplementary Planning Document: [name] 2010 (SPD) which specifically seeks to deal with the scale and detailing of these building elements in combination.

With regard to the changes in the roof form to the front of the property, there would be no conflict with the design policies of the development plan. Furthermore, in isolation, the individual elements satisfy the SPD. However, as the plans do not indicate how the rear alterations would be finished or demonstrate that they would have a satisfactory relationship, this element would be at odds with the SPD. Without plans that accurately show how this arrangement would work in practice, I am not persuaded that it would not result in poor design. This particular combination of elements does therefore conflict with the design aspirations of policy DM1 A of the Harrow Development Management Policies (2013) and policy D3 of The London Plan (2021). As these policies generally accord with the design requirements of the National Planning Policy Framework, I afford them full weight.

In conclusion, the works to the frontage of the property would be acceptable. However, the plans do not accurately demonstrate how the combination of the proposed dormer and the revised rear roof form of the two storey rear extension would be achieved. It would appear that it would represent poor design and in any event, the plans are not consistent and are not a suitable basis for a planning permission. I therefore dismiss the appeal.