Appeal 3287396

The part of the appeal that relates to the rear loft roof dormer conversion and two new rooflights to be added to the front of the property is dismissed.

The part of the appeal that relates to the single storey extension, conversion of outrigger roof and new double glazed windows is allowed. Planning permission is granted for the replacement of the constructed lean to extension with a single storey outrigger extension and infill with dual pitched roofs, outrigger roof converted from pitched to flat to match neighbouring outrigger and new double glazed windows to retained window openings at [site address] , Islington, London [postcode] , in accordance with the terms of the application Ref: P2021/1942/FUL, dated 5 July 2021, and subject to the following

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: P1-101, P1-102, P1-103, P1-104, P1-105, P2- 101, P2-102, P3-101 and P0-001 Context Plan, only in so far as they relate to the single storey rear extension, conversion of the outrigger roof and new double glazing to retained window openings.

The materials to be used in the construction of the external surfaces of the conversion of the outrigger roof, from pitched to flat, hereby permitted shall match those used in the existing building.

The site visit was undertaken by an Appeal Planning Officer whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

In the formal decision I recommend minor changes to the description of development to include only that which relates to an act of development.

I recommend a split decision on the basis that the single storey outrigger and infill extension, conversion of the outrigger roof and new double glazing are severable from the rear loft dormer. However, the installation of the two front rooflights are part of the design of the loft conversion and so are not readily severable.

The Council have only raised substantive concerns with the rear dormer and single storey rear extension and not the remainder of the proposal, and I see no reason to disagree. The recommendation below will therefore focus on these two elements of the proposed development.

The main issue is the effect of the proposed rear loft dormer conversion and single storey outrigger and infill extension on the character and appearance of the area.

The appeal site is a three storey, terraced property on the western side of [address], close to the junction with Aubert Park. At the rear there is a two storey outrigger feature with a lean to extension at ground floor level. The wider terrace is characterised by broadly uniform dwellings, a number of which have ground and loft level extensions. There are several rear dormer extensions on the appeal terrace and at nearby dwellings on Aubert Park, some of which have roof terraces with glass or metal balustrades. It also appears that the ground floor extensions of the appeal terrace mainly have flat roofs.

The proposed dormer would cover the full width of the rear roof slope and would not be set down from the roofline. The dormer would have large arched openings and a roof terrace with a glass balustrade. It would be finished with timber panels and London stock brick, laid in a soldier course bond at low level.

The existing rear dormers in this area have been constructed using a variety of materials but predominantly use material types and colours that are similar to one another and respond to those used on the host dwelling. The proposed timber panels and orientation of the London stock brick do not appear to be established material choices at loft level in this area, and their introduction would disrupt the general design pattern that characterises dormers on this terrace. Given its significant height, the dormer would be viewed within the wider context of the existing dormers from a large number of nearby properties. The proposed materials would be overly prominent and appear as an incongruous addition to the terrace’s roofscape, to the detriment of its character and appearance. While the size and positioning of the openings would be acceptable, their arched shape, in addition to the introduction of new external materials, would result in an overall discordant design.

While relevant policies do not specifically require matching materials, the proposal must be considered with regard to how it would be seen in the context of nearby dormers and on a terrace characterised by a general uniformity.

I noted that roof terraces form part of the character of the area and there is an existing example with a glass balustrade on the appeal terrace. However, the significant addition of balustrade glazing, in combination with the proposed materials and openings, would result in an overly prominent design that would be out of keeping with the roof terraces in this area. The Urban Design Guide Supplementary Planning Document (SPD) identifies visual prominence as a main consideration when introducing a roof terrace, given the above, the proposal would conflict with the aims of this document.

For the above reasons, the proposed rear loft dormer conversion would result in harm to the character and appearance of the area. As such, it would be contrary to Policy DM2.1 of Islington’s Local Plan: Development Management Policies, adopted June 2013, which seeks to ensure that development proposals respect their wider context and address the design detailing, such as the colour and type of materials, of the site and its surroundings. The Council have mentioned conflict with [name], adopted February 2011, specifically Policy CS8 which, although more strategic in nature, nevertheless seeks to ensure that the scale of development reflects the character of the area. With regard to scale, the proposed dormer would not conflict with this Policy, however, this would not outweigh the harm identified against Policy DM2.1.

The Council have referred to The London Plan, adopted March 2021, specifically Policy D1, which primarily focuses on the preparation of local plans in each borough, and Policy D4 which focuses on the design process and scrutiny. [name] are principally strategic in nature and do not appear directly relevant to the modest nature of the appeal scheme.

The single storey extension would replace the lean to extension and include a set back element to infill the gap between the outrigger and shared boundary with No 5. The extension would have dual pitched roofs that slope towards the site’s side boundaries and the infill would incorporate a glass rooflight box. Similar to the proposed dormer, the single storey extension would be finished with timber panels, low level, soldier course, London stock brick and large arched openings.

While the proposed pitched roofs would differ from flat-roofed extensions on the appeal terrace, the tallest part of these roofs would extend only a short distance above the rooflines of the neighbouring extensions. Due to its moderate footprint and height, the proposed extension would not dominate the rear elevation of the main dwelling and would only be visible to a limited number of surrounding properties. The proposal would introduce new materials and opening designs to this terrace. However, given its discrete location, the proposed design would be suitable in this context and would not harm the character and appearance of the area. The SPD states that rear extensions must be subordinate to the original dwelling, for the above reasons, the proposal would comply with this aim of the document.

Given the above, the proposed single storey outrigger and infill extension would not result in harm to the character and appearance of the area. It would accord with Policy DM2.1 of the Islington Local Plan: Development Management Policies which seeks to ensure that development proposals respect and respond positively to existing buildings. It would also comply with Policy CS8 of [name] which seeks to ensure that the scale of development reflects the character of the area. As mentioned before, The London Plan Policies D1 and D4 do not appear directly relevant to the modest nature of the appeal scheme.

In addition to the standard time period for commencement of the development, I recommend a condition requiring the development to accord with the approved plans as this provides certainty. I also recommend that matching external materials are used in the conversion of the outrigger roof to preserve the character and appearance of the dwelling. There is sufficient detail regarding the use of materials for the single storey extension included within the approved plans, therefore a separate condition to control the use of materials in this regard is not considered necessary.

The officer report refers to obtaining further detail with regard to the proposed double glazing. However, there is a lack of information as to why this would be required and so a condition to secure this detail is not considered necessary.

There is a request for at least one swift nestbox or brick to be installed in order to protect the local population. However, there is insufficient submitted evidence to suggest that the proposal would harm the local swifts or that providing this habitat would lead to measurable net gains for biodiversity. Therefore, a condition to secure this request is not considered necessary.

For the reasons given above, and having regard to all other matters raised, I recommend that in relation to the rear loft dormer conversion and two new rooflights to be added to the front of the property, the appeal is dismissed. However, I recommend that in relation to the replacement of the constructed lean to extension with a single storey outrigger extension and infill with dual pitched roofs, outrigger roof conversion from pitched to flat to match neighbouring outrigger and new double glazed windows to retained window openings, the appeal is allowed.

I have considered all the submitted evidence and the Appeal Planning Officer’s report and, on that basis, a split decision is issued as set out in the formal decision above.