Appeal 3324406

The appeal is allowed and planning permission is granted for a part first floor rear extension at [site address] in accordance with the terms of the application, Ref 00707/761/P7, dated 6 March 2023, 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 plans: 3670/HH-01/JD; 3670/HH-02/JD; 3670/HH-03/JD and 3670/HH-04/[name].

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.

No additional windows or openings shall be formed in the eastern side elevation of the development hereby permitted.

I have used the Council’s description of development in the above banner heading as it accurately describes the proposed development.

The main issue is the effect of the proposal on the character and appearance of the host property and the surrounding area.

The appeal property is a two storey, end of terrace dwelling, located in a row of dwellings of a similar original design and appearance. The appeal property has an existing part two storey, part single storey outrigger on its rear elevation.

Policies CC1 and CC2 of the London Borough of Hounslow Local Plan 2015-2030 (2015) (LP) expect proposals (amongst other things) to respond to the context and character of the area in terms of design, whilst Policy SC7 requires residential alterations to complement the original building and harmonise with adjoining properties. The Council’s Residential Extensions Guidelines Supplementary Planning Document (2017) (SPD) whilst non-statutory, provides useful design guidance. The SPD advises that first floor extensions should be proportionate and subordinate to the dimensions of the main house. It also states that the width of a first-floor rear extension should be no greater than half the width of the original house.

The width of the extension would be slightly greater than half the width of the dwelling and accordingly, the proposal would not comply with this aspect of the design guidance set out in the SPD. However, the extension would be the same width as the existing two-storey outrigger and accordingly, I find that the proposal would not be materially harmful to the character and appearance of the dwelling in this regard.

The proposed first floor extension would add a further 3 metres in depth to the existing two storey outrigger. However, its height and flat roof design would match that of the existing two storey outrigger and the extension would continue to sit well below the eaves of the dwelling. In my view, the proposed extension would respect the proportions of the host dwelling and would be read as a subservient and subordinate addition. I therefore conclude that it would not have a harmful effect on the character and appearance of the host dwelling.

I saw on my site visit that several other dwellings within the terrace also have outriggers of varying depth. The two-storey outrigger to the adjoining dwelling, [address], is of a similar depth to the appeal proposal. The Council state that this extension does not appear to have planning permission and should not therefore set a precedent for similar forms of development. Nonetheless, the extension appears long established and forms part of the surrounding context, along with other two storey flat roof outriggers on the rear elevation of some of the properties within the same terrace.

I noted that views of the proposed extension and the resultant deep flank wall of the outrigger would be obtained from [address] and from the adjoining access. However, given the surrounding context, the limited height and scale of the extension and its subordinate appearance to the host dwelling, it is my view that the extension would not appear overly dominant or incongruous in the street scene and accordingly, would not be materially harmful to the character and appearance of the surrounding area.

Thus, in conclusion on this main issue, I find that the proposal would not have a harmful effect on the character and appearance of the host dwelling and the surrounding area. Accordingly, it would comply with the design objectives of Policies CC1, CC2 and SC7 of the LP, and the National Planning Policy Framework (2021).

In addition to the standard implementation condition, the approved plans condition is imposed for certainty. A condition requiring the use of matching materials is necessary to protect the character and appearance of the dwelling and the local area. I have imposed a condition preventing the formation of additional windows and other openings in the eastern side elevation to protect the living conditions of adjoining occupiers.

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