Appeal 3351330

The appeal is allowed and planning permission is granted for a single and two storey rear extension; pitched dormer to side roof slope; single storey rear extension to detached outbuilding; external alterations (Demolition of conservatory) at [site address] in accordance with the terms of the application, [name]/1401/24, subject to the following conditions:

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: Location Plan Existing (SR01 [name]), Site Plan Existing (SR02 [name]), Site Plan Proposed (SR03 [name]), Ground Floor Plan Existing (SR04 [name]), First Floor Plan Existing (SR05 [name]), Roof Plan Existing (SR06 [name]), [name] (SR07 [name]), [name] (SR08 [name]), [name] (SR09 [name]), [name] (SR10 [name]), [name] (SR11 [name]), Sections 01 Proposed (SR11 [name]), [name] (SR12 [name]), Sections 02 Proposed (SR12 [name]), Ground Floor Plan Proposed (SR13 [name]), First Floor Plan Proposed (SR14 [name]), Roof Plan Proposed (SR15 [name]), [name] (SR16 [name]), [name] (SR17 [name]), [name] (SR18 [name]), [name] (SR19 [name]).

The external materials of the extension hereby permitted shall match those used in the existing building.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The appeal proposal was described on the application form as a ‘Double storey rear extension including internal and fenestration alterations, followed by a single storey extension to existing outbuilding’. However, I note that the Council’s decision notice describes the proposal as a ‘Single and two storey rear extension; pitched dormer to side roof slope; single storey rear extension to detached outbuilding; external alterations (Demolition of conservatory)’. The appellant has also described the proposal in a similar vein in their appeal statement. Given the proposal before me, and for consistency, I have utilised the wording on the Council’s decision notice.

The main issues in the appeal are: • the effect of the proposed development on the character and appearance of the host dwelling and surrounding area, • the effect of the proposed development on the living conditions of the occupants of No.[address] with regards to outlook.

[site address] comprises a unique property within the street scene due to its detached nature and unique architectural Tudor style design. This gives the property its own distinctive character, setting it apart from the rest of the terraced properties seen along [address]. These properties consist of a mixture of Edwardian and Victorian architecture, and many feature large two-storey extensions to the rear of them.

The materials seen to the façade of No. 24 include white rendered walls with a half-timbered front-facing gable. The property currently benefits from a detached structure with a separate garage, a side-facing dormer and a generous amount of garden space to the rear.

The proposal seeks permission for a ‘Single and two storey rear extension; pitched dormer to side roof slope; single storey rear extension to detached outbuilding; external alterations (Demolition of conservatory)’.

The council refers to the [name] (HRDG) within their delegated report. This guide states that extensions should retain proportion and balance in their relationship to the original building and should not dominate the host property or surrounding streetscape.

When applying this guidance to the proposal, it is considered that the rear extension itself is well balanced and would appear harmonious with the host property due to the existing roof pitch and ridge height being retained. The additional dormer to the side elevation is also considered to assimilate well with the existing dormer due to it being identical in scale and form. The existing dormer sits at the front, consequently screening the proposed dormer. Therefore, it will not significantly alter the appearance of the dwelling when considering the view from the street scene.

I agree with the council that the extension is of a considerable size due to its depth exceeding over 50% of the depth of the original dwellinghouse. The HRDG highlights that extensions should not ‘dominate the original building or the surrounding streetscape’. There will be limited to no visibility of the rear element of the proposal from the street scene, and, due to its form and matching materials, I consider that the extension will read as a sympathetic extension of the original dwellinghouse rather than dominating the existing building. Thus, it reflects the guidance set out in the HRDG and accords with criteria ‘b’ of Policy DM1 of Harrow Development Management Policies Local Plan 2013.

Many of the terraces along [address] can be seen with larger, two-storey rear extensions, including the neighbouring property immediately north of the appeal site. Thus, I do not consider the addition of a two-storey extension incongruous within its surroundings given that this pattern of development is already existing on a larger scale on many of the properties along the street. Additionally, the appeal site benefits from a generous amount of garden space to the rear and I therefore consider that there is sufficient space at the site to accommodate the proposed extension.

However, the council have expressed that, due to No. 24 and No. [address] to their dividing boundary, the bulk would appear as overwhelming and that the design principles for terraced properties should apply. The HRDG states that ‘Two storey rear extensions on terraced properties will be resisted’. I agree that the properties sit closely together, and that the depth of the two-storey element extends along the dividing boundary by a considerable amount. However, I consider that the pitch of the roof, which will slope away from No. 28, will reduce the impact of the extension and its two-storey appearance. Therefore, the application of terraced-property design principles should be applied lightly as the properties are detached from one another and present as such visually due to their differences in form and character.

Considering the above, I conclude that the extension retains the character and form of the host property and that the scale is acceptable in the context of its surrounding area. The extension also sits comfortably within the property’s surrounding curtilage. The council raises no concerns regarding the proposed demolition of the conservatory nor the proposed extension to the outbuilding. The proposal is therefore consistent with design Policies D1 and D4 of the London Plan (2021), Policy CS1 of the [name] (2012), Policy DM1 of the Harrow Development Management Policies Local Plan 2013 which, amongst other matters, require development to achieve a high standard of design that complements the character of the area.

I acknowledge that the depth of the extension, which extends forward of No. 28’s rear wall, could give rise to a sense of enclosure and dominance due to its proximity to the shared boundary. However, as discussed above, the roof pitch results in the extension sloping away from this dividing boundary. Therefore, the part of the extension that sits closest to the neighbouring property is not considered to be significantly overbearing.

The plans demonstrate that the 45-degree angle drawn from No. 28’s nearest first-floor window will be intercepted by the two-storey extension. However, I note that this window has obscured glazing in place and serves a bathroom, which is not a 'protected window' as defined within the HRDG. Therefore, the proposal is not considered contrary to criteria ‘f’ set out under Policy DM1, as this seeks to resist development which would impact the outlook from ‘habitable rooms and kitchens’ only.

Taking the above into account, I do not consider the extension to be significantly harmful to the living conditions of No. 28. Consequently, the proposal is considered acceptable and accords with Policy D3 of the London Plan (2021), and Policy DM1 of the Harrow Development Management Policies Local Plan 2013 which, amongst other things seek to ensure that the massing, bulk, scale and height of proposed buildings do not impact on the living conditions of neighbouring occupiers. I have also had regard to the adopted HRDG.

In addition to the standard three-year period implementation condition, which is a statutory requirement, it is necessary, in the interest of certainty, to define the plans with which the appeal scheme should accord. In order to protect the character and appearance of the surrounding area and the host dwelling, I am attaching a condition requiring materials used in the construction of the external surfaces of the development to match those used in the existing building.

For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be allowed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is allowed.