Appeal 3318390

The appeal is dismissed.

I have utilised the Council’s description of the development as per the decision notice as I feel it more concisely describes the development.

The main issue is the impact of the proposal upon the host dwelling and neighbouring properties as well as the character and appearance of the Three Sisters Conservation Area.

The appeal site relates to a two-storey mid terraced dwelling located within the [name] conservation Area (CA). Section 72 of the Planning (Listed Buildings in Conservation Areas) Act 1990 requires that special attention shall be paid to the desirability of preserving and enhancing the character and appearance of the CA. In this context, preserving can also mean doing no harm. The proposal seeks permission for alterations including erection of a mansard roof extension to the main rear roof (with French doors and safety railings and raising ridge heights) and a roof extension above the two-storey back addition. The proposal also includes installation of solar panels to the roof. The solar panels are already on the property and would be relocated atop the proposed extensions. The plans also show installation of three rooflights to the front elevation.

At the time of my site visit, and from the evidence before me, I note that only three properties along [address] have three rooflights to the front roof slope. These are either incomparable in terms of width, have been approved under a previous policy regime, or indeed it being unclear if they were included on previous applications. Whilst rooflights in general are characteristic of [address] I find that this is generally limited to no more than two rooflights as previously approved. I find that three rooflights would be too much, and intrusive, for the front of the property. I note the appellant’s comment regarding light levels, however, the bedroom which the rooflights would serve would also benefit from a full height window to the rear elevation. I have no reason to believe that the bedroom would have insufficient light levels with a reduced number of rooflights. I find that this element of the proposals, the three rooflights to the front roof slope, would cause less than substantial harm to the CA. This is discussed further later within this decision letter.

The proposed raising of the ridge height would be similar to the previous approval (2021/0766). The proposal would maintain the pitch of the existing roof slope and extend to the rear. The existing party walls would aid in reducing visual impact, and overall, the increase in height would only be noticeable when standing directly in front of the host dwelling. It would appear, from my site visit, that several properties along the street have increased their ridge height already. The proposal to raise the ridge height would continue this form of development and the Council have found that this element would remain acceptable in design terms. I have no reason to conclude differently on this element.

As outlined, a permission has been previously granted for a similar scheme, with the main difference between the existing permission, and the current appeal proposal, being scale and form of the rear extension. The extensions would now extend the full depth of the two-storey back addition as well as raising the back addition’s eaves with a flattened roof pitch. The proposal would be over the existing footprint of the appeal site, and I do not find that this would result in a bigger footprint extension which would be overbearing. Whether a flat roof or pitched roof I find that a proposal to extend over the entire outrigger would result in broadly similar impacts and the existing extensions and alterations at the neighbouring property (shown in image 4 of the appellant’s statement) share design queues with the proposal which is the subject of this appeal.

I acknowledge that the neighbouring extensions are not of the same depth, and they have thus retained the outrigger pitched roof to some extent (which would be lost at the appeal site) but, as a result of these existing extensions, the balance of the pair within this row is already lost and is imbalanced. I find that the proposed design would improve the balance of the new loft on the outrigger and would, overall, be better balanced with the neighbouring property once complete even with one pitched and one flat roof on the respective outriggers. Overall, the extensions would largely mirror each other in design terms.

The existing design, previously approved, created a new loft mansard that was almost the same height as the outrigger. I find that the proposal before does create better proportions to the outrigger with the brickwork of the original dwelling remaining dominant and the mansard roof extension would still remain subservient to the host property. The proposal would maintain overall uniform nature within the street scene but, as with most sites of this nature, there is greater variation within the built form in the vicinity as a result of various alterations and extensions to the rear of the dwellings in question. I do not find that the proposal would result in an over dominant and incongruous addition which would relate poorly to the host and neighbouring properties.

At the time of my site visit, and as evidenced within the submissions before me, there are a number of built additions and external alterations which have become part of the character of the area. It is key, within the CA, to maintain control over insensitive alterations and extensions that would spoil the appearance of the traditional hipped roofs by allowing only extensions at roof level that would not be visible from the street. In this case, the proposal would not be visible from the street and would not be on a dwelling close enough to corners that would be clearly visible from the street. The proposal would not, therefore, be visually intrusive. The proposals to the roof would respect the scale and style of the house, taking into account design of adjoining development, and would not be visible from the street.

The CA has an Appraisal and [name] (AMS) which notes that [address] lies detached from the rest of the CA and that houses are arranged in one long terrace. The proposal, for the mansard roof extension to the rear roof and extension above the two storey back addition, would not conflict with the features which are noted within the AMS. Given the varied character of alterations within the vicinity, and limited visibility I do not find that the rear roof extensions would cause harm to the character or appearance of the CA.

In terms of materials, the proposal seeks to include artificial slate, zinc cladding and aluminium frames. The zinc cladding would be similar to the previous approval and a condition could be placed upon any permission granted to ensure an appropriate finish in that regard. The Council have not raised any refusal reason based upon relocation of the solar panels and I have no evidence before me to conclude differently.

To summarise, I do not find that the rear roof extensions or solar panel relocation would cause harm to the character or appearance of the host property, neighbouring properties or the CA. These elements would preserve the CA. In this context, preserving can also be taken to mean doing no harm. Despite this I find that the three rooflights to the front elevation would result in visual clutter to the front roofscape within the street scene of the CA. I find the proposal would result in less than substantial harm to the CA as a result of the number of rooflights proposed to the front elevation.

The National Planning Policy Framework 2021 (the Framework/NPPF) states, in paragraph 199, that 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. In accordance with the Framework, paragraph 202, 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 proposal is for alterations to a single residential dwelling, and I have no evidence before me to support that the proposal would result in any public benefits or is securing optimal viable use to outweigh the weight which should be given to the harm which has been identified

The mansard roof extension and extension above the two-storey back addition would be consistent with Wandsworth Local Plan Development Management [name] 2016 (DMP) Policy DMH5 which requires that proposals for extensions and alterations to existing residential properties be permitted where the extension is well designed and is not so large that it dominates and competes with the original building, and that an extension, dormer window or other alteration to the roof is confined to the rear of the building.

The proposal, for the three front rooflights, would be contrary to DMP Policy DMS 1 which requires that the appearance of the development contributes positively to local spatial character and DMP Policy DMS2, which confirms that applications affecting a heritage asset will be granted where it is in accordance with the NPPF and where they sustain, conserve, and where appropriate, enhance the significance, appearance, character and setting of the heritage asset itself.

The Council’s refusal reason refers to a number of policies and guidance documents. As part of the appeal, I have only been sent copies of DMP Policy DMS1, DMS2 and DMH5. No further documentation has been submitted. Even if I had copies, the outcome of the appeal would have been the same as a result of the less than substantial harm identified as a result of the number of skylights to the front roof slope.

I note comments have been submitted both in support of, and in objection to, the proposal. A lack of objection is a neutral consideration. The Battersea Society is noted to object to the addition of three rooflights, however, I have dealt with this in the main issues above.

An objection has raised concern with regard to outlook, light and enclosure. The Council has assessed amenity impact and note that a separation distance of around a metre would be maintained with the second-floor rear window and a separation distance of around 4 metres would be maintained with the centre of [address]’s rear windows to the main elevation. The Council have not found any reason for refusal due to impact on neighbouring occupiers in regard to outlook, loss of daylight/sunlight or overbearingness and based upon the evidence before me, and my site visit, I have no reason to conclude differently on these elements.

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