Appeal 3329225

The appeal is dismissed insofar as it relates to the erection of a single storey rear extension and alterations to a first floor window. The appeal is allowed and planning permission granted insofar as it relates to the garage conversion at [site address] in accordance with the terms of the application, [name]/1860/23, dated 20 June 2023, 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 insofar as the details relate to the garage conversion shall be carried out in accordance with the following approved plans: GC14-AP1-101; GC14-AP1-102; GC14-AP1-103 and GC14-AP1-104.

The materials to be used in the construction of the external surfaces and window of the development hereby permitted shall match those used in the existing building.

The drawings relating to the appeal scheme were obtained from the Council’s portal.

It is considered that the main issue is the effect of the proposed development on the living conditions of the occupiers of [address].

The appeal property is a semi-detached dwelling situated within a primarily residential area. The proposed development includes both the conversion of the integral garage into a habitable room, together with the erection of a wall with an opening, and the erection of a single storey rear extension.

In its reason for refusal, the Council has not specifically objected to the conversion of the garage to a habitable room. Based upon what was observed during the site visit, there are no reasons to disagree with the Council’s assessment. Therefore, consideration has been given to the potential for a split decision to be issued. For such a decision to be issued the relevant parts of the appeal scheme must clearly be physically and functionally independent. In this case, the proposed garage conversion is clearly severable, and both physically and functionally independent, from the proposed rear extension. There exists, therefore, the potential to issue a split decision in this case.

As noted by the appellant and subject to height considerations, there is the potential for a single storey rear extension to be erected as permitted development with a depth of 3 metres adjacent to the shared boundary with [address]. Significant weight is given to the potential for a 3-metre extension to be erected albeit the appeal scheme is required to be assessed against the relevant development plan policies. Reference is also made by the appellant to the potential for erecting a 6-metre long rear extension albeit subject to the prior approval process but there is no evidence that such an application has been determined.

The front elevations of the property and No. 16 face towards south and, based upon the observations made during the site visit, the levels of sunlight and daylight reaching the rear windows of these dwellings is at a lower level than the front windows. The balconies at first floor level project away from the rear elevations of these dwellings and, as such, overhang the ground floor windows which serve dining rooms and kitchens. Along the shared boundary between the dwellings is a timber fence which is initially about 2-metres in height and reduces to around 1.8-metres. There are also some evergreen trees within the garden of No. [address] to the boundary. In combination, the balconies, wooden fences and trees create a sense of enclosure to the rear of the dwellings when viewed from the nearest windows and the patio areas immediately adjacent to the rear elevations.

Policy DM 1 of the Harrow Development Management Policies Local Plan (DMP) refers to the consideration the adequacy of light and outlook within buildings and outdoor spaces. There is guidance contained in the Council’s Harrow Residential Design Guide Supplementary Planning Document (SPD) stating that extensions should not cause any unreasonable loss of light or overshadowing to any habitable rooms and kitchens in neighbouring properties, or to gardens, in particular to the area immediately to the rear of the house. To achieve this the SPD refers to the side elevation of an extension being set back from a shared boundary.

By reason of the proposed extension’s siting adjacent to the shared boundary, together with its length and height, it would represent an unacceptable overbearing form of development when viewed from the rear windows and the patio area immediately to the rear of No. 19. Also, the proposed extension would unacceptably contribute to a further increase the sense of enclosure for the occupiers of No. 19 which has been identified. Although on its own it is not a reason for this appeal to fail, there would be reduction in levels of day and sunlight reaching the rear windows and patio area of No. 19 which adds to the unacceptable harm which has already been identified. In this case, the level of harm identified is sufficient to outweigh the available permitted development rights to erect a 3-metre extension.

Accordingly, it is concluded that the erection of the proposed single storey rear extension and alterations to a first floor window would conflict with CS Policy CS1(B), DMP Policy DM 1 and the guidance contained in the SPD because it would cause unacceptable harm to the living conditions of the occupiers of [address]. Conversely, it is concluded that the proposed garage conversion would not cause unacceptable harm to the living conditions of the occupiers of No. 16 and, as such, it would not conflict with the requirements of with CS Policy CS1(B), DMP Policy DM 1 and the guidance contained in the SPD. A split decision could, therefore, be issued in this case. Policy D3 of The London Plan is more particularly directed at optimising site capacity through a design-led approach rather than being a detailed development management policy for householder extensions.

No conditions have been suggested by the Council. However, consideration has been given to the need for necessary conditions, so far as they related to the proposed garage conversion, which accord with the tests in the National Planning Policy Framework and National Planning Practice Guidance. A condition requiring the garage conversion, including the installation of the window and erection of a wall, being undertaken in accordance with the submitted drawings is necessary for reasons of good planning and for the avoidance of doubt. The proposed external materials to create the habitable accommodation, in particular the wall and window frame, should match those of the host property and a condition is necessary to secure this.

Accordingly, the appeal is dismissed in respect of the proposed single storey rear extension and alterations to a first floor window but allowed for proposed garage conversion.