Appeal 3334123

The appeal is dismissed.

The main issue in this case is the effect of the proposed dormer on the significance and character of the host building and surrounding buildings, their setting, and on the character and appearance of the Castelnau Conservation Area.

The appeal site is a three storey semi-detached Edwardian villa. The house is of yellow London stock brick with a bay window at the front; stucco detailing to bay windows and front door porch surround with two pilasters and pediment over; sliding sash windows, with brackets to eaves; large dormer windows have been added to front and rear elevations set close to the eaves. The other half of the semi-detached pair also has dormers to the front, rear and side, I am told pursuant to planning permissions in 1992 and 2002. Similarly, Nos.15 and 17 have historic roof extensions.

The site is located within Castelnau Conservation Area, which forms part of a high-quality consistent townscape of grand semi-detached and detached villas set back from the pavement and presenting fine intricate Italianate detailing. There is a consistency of appearance, with matching features such as hipped roofs, stuccoed elevations and tall central chimney stacks. At roof level, the buildings have experienced alterations with some featuring side and rear dormers. However, mostly these are modest in size and form and thus do not significantly detract from the character of the building, the symmetry of the pair and their contribution to the conservation area, and many pre-date current local plan policies.

The starting point is the legislation and planning policy. Section 72 of the Planning (Listed buildings and Conservation Areas) Act 1990 requires that special attention shall be paid to the desirability of preserving or enhancing the character or appearance of the Conservation Area. The parties are familiar with development plan policies, so that I will simply say that the following policies are the most relevant. Policy HC1 of the London Plan states that development proposals affecting heritage assets, and their settings, should conserve their significance, by being sympathetic to the assets’ significance and appreciation within their surroundings. Policy LP1 of the Local Plan 2018 seeks to maintain and, where possible, enhance the high architectural and urban design quality which contributes to the character and heritage of the area.

Chapter 16 of the December 2023 National Planning Policy Framework (the Framework), Paragraph 205 states “When considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation (and the more important the asset, the greater the weight should be). This is irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to its significance”. Paragraph 208 adds that, “Where a development proposal will lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use”.

The appellant argues that dormer windows are now a part of the character and appearance of the host property and its neighbours. The proposed dormer is modest in size and would be constructed with lead covering to its cheeks, surrounds and roof. It would not dominate the roof and is subservient in scale. Its front elevation has slopes at both sides so that its impact on the roof is even less than the side dormer window at [address], the other half of the pair, which in any event are appropriate in design and materials. They preserve the character and appearance of the heritage assets.

I do not agree with this assessment. I consider that the existing dormers on the appeal dwelling, identified as a ‘Building of [name], and on the group of properties to which it belongs, are already harmful. They are very much at odds with the shallow hipped roof form. The proposed dormer would have lead cladding to the cheeks, roof and front surrounds and traditional sash windows with painted finish timber, which would not be as harmful as the existing dormers but would nevertheless add to the harm and encourage pressure for further unsatisfactory development. It would be an addition detrimental to the character of this dwelling, and the conservation area. This would amount to less than substantial harm.

I appreciate that the dormer would enhance the living accommodation within the roof space of the property, providing better space within the bathroom, and better natural light and ventilation, and be an improvement to the house. But this is a private, not a public benefit. Nor can I accept that it would amount to other than a minimal addition to the local housing stock.

The appellant accepts that the existing box dormers are not attractive features, but notes that it is possible that they will, at some future time, be altered so as to have a more appropriate appearance. It is the implementation of the policy and the resistance to further harm that is most likely to bring this about.

For the reasons that I have set out above, the appeal will be dismissed.