Appeal 3310269

The appeal is dismissed insofar as it relates to the erection of a single storey extension to the rear.

The appeal is allowed insofar as it relates to conversion of roof space to habitable use to include a rear dormer with 2 front roof lights.

Planning permission is granted for conversion of roof space to habitable use to include a rear dormer with 2 front roof lights at [site address] , Hillingdon [postcode] in accordance with the terms of the application, Ref 77168/APP/2022/978 dated 22 March 2022, and the plans submitted with it, so far as relevant to that part of the development hereby permitted and subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plan, [name]: EA68-01-1002A in so far as it relates to the conversion of roof space to habitable use to include a rear dormer with 2 front roof lights.

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

The Council changed the description of development from that stated on the application form in the interests of clarity. I consider that the amended description accurately describes the appeal scheme and accordingly I have adopted the amended description in the heading above.

Amended plans were submitted prior to the application’s determination to revise the design of the proposed single storey rear extension: [name]: EA68-01-1002A. I have considered this appeal on the basis of the amended plans submitted.

The Council considered that the conversion of roof space to habitable use to include a rear dormer with 2 front roof lights was acceptable. I have no substantive evidence to lead me to a different conclusion upon this part of the proposed development.

The main issues in this appeal are the effect of the single storey extension to the rear on (i) the character and appearance of existing property and area in general; and (ii) the living conditions of occupiers of No. [address].

The site is a mid-terraced property within a predominantly residential area. The appeal site is a modest property in a terrace of similar properties, surrounding properties vary in design however there is a uniformity in terms of palette of materials.

Policy DMHD 1 of the London Borough of Hillingdon, Local Plan Part 2 Development Management Policies (2020) (the Local Plan: Part 2) outlines recommendations for the depth and height of rear extensions. The proposed development would not exceed the recommendations.

The proposed single storey extension would include sloping the roof of the rear extension along the southern boundary adjacent the shared boundary with No. [address], creating an asymmetrical roof design. Whilst this is not a common roof type within the area, the design appears contemporary and would not be an unsympathetic or incongruous addition to the existing modern property.

I conclude that the proposed development would not harm the character and appearance of the existing property and area in general. There is no conflict with Policy BE1 of the [name] for 2026, Local Plan: Part 1, [name] (2012) (the Local Plan: Part 1) and [name] 11, DMHB 12 and DMHD 1 the Local Plan: Part 2 which amongst other things seek to ensure developments are of high quality design which respect the design of the original property and surrounding area.

The appeal site and No. [address] are staggered in terms of building line, No. 70 sits further forward towards the adjacent road than the appeal site and has a detached garage located adjacent the rear elevation projecting back into the rear garden.

The extension has been revised to incorporate a sloped roof reducing the height adjacent the shared boundary to mitigate the effect of the development on the neighbouring property, No. 70. Notwithstanding this the set back of the appeal site, along with the location and scale of the existing detached garage the proposed extension would be stark and create a sense of enclosure for the occupiers No. 70.

The stagger in properties and the orientation of the proposed extension would have an overbearing and overshadowing effect on the occupiers of the adjacent property. I find that the proposed development would harm the living conditions of the occupiers of No. [address].

There is conflict with [name] 11 and DMHD 1 of the Local Plan: Part 2 which amongst other things seek to protect the amenities of occupiers of neighbouring properties.

I have found that the proposed development would not harm the character and appearance of the area or existing property, however this does not outweigh the harm I have identified in terms of living conditions of occupiers of No. [address].

I find the proposed conversion of roof space to habitable use to include a rear dormer with 2 front roof lights is clearly severable both physically and functionally from the erection of single storey extension to rear.

I conclude that the appeal should succeed in relation to the conversion of roof space to habitable use to include a rear dormer with 2 front roof lights. However, in relation to the erection of single storey extension to rear, the appeal should be dismissed.

In respect of the conversion of roof space to habitable use to include a rear dormer with 2 front roof lights I have attached the standard time limit condition and a plans condition as this provides certainty. I have also added conditions concerning materials to ensure a satisfactory appearance.