Appeal 3371054

The appeal is allowed and planning permission is granted for a single storey wrap around, part first floor rear, two storey side, loft extensions (including construction of side & rear dormer and installation of sky light on the front roof slope), involving demolition of existing garage at [site address] in accordance with the terms of the application, [name]/2025/1155, 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: ART/2025/EXT112NHR/SPLP [name], ART/2025/EXT112NHR/PL01 [name], ART/2025/EXT112NHR/PL02 [name], ART/2025/EXT112NHR/PE [name] and ART/2025/EXT112NHR/FE [name].

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

The main issue is the effect on the character and appearance of the appeal dwelling and that of the local area.

The appeal dwelling is a detached two storey 20th century house, designed in a traditional style with a pyramid roof form. It is located on a street that demonstrates a wide variety of property types, scales and architectural expressions. This lends the local area a varied streetscape, with little cohesion in its street frontages. On the day of my site visit it was apparent that the roof, attached side garage with stores and some walls of the appeal dwelling had been removed, although no new construction was evident.

The proposal is for extensions that would significantly increase the living area of the appeal dwelling, particularly through the proposed addition of a two storey side extension and loft conversion with rear and side dormers. This side extension would have the same footprint as the now demolished side garage and stores, incorporating a new front main entrance to the appeal dwelling.

The first floor of the side extension would, be set well back from the front elevation of the appeal dwelling. At roof level the roof of the proposed side extension would be hipped with the existing pyramid roof form and would incorporate a traditionally formed side dormer with a hipped roof form. This dormer would be positioned well back from the front elevation.

The design guidance in the 8. The Hounslow Character, Sustainability and [name] A5 [name] (2021) (the SPD), advises in paragraph A535 that the roofs of extensions should be set down from the height of the original roof by 0.5 metres. However, this is design advice that should be applied to the circumstances and context. In this instance, due to the pyramid form of the existing roof, the matching height of the roof of the proposed extension, results in a more homogenous single roof form.

This would have the benefit of not looking like a series of roof parts that do not align. Consequently, the proposed extensions as whole would appear more coherent and appropriate to the larger scale of property that would result from the proposal. For these reasons, I find that proposal would accord with the SPD’s design objective of preventing extensions that harm the character of the house and local area.

Replacing the existing main front entrance to the appeal dwelling with windows and creating a new main entrance in the front of the proposed side extension would alter the appearance of the appeal dwelling, which is a traditionally designed and propertied house of little architectural note. The proposed new entrance would reflect the traditional design and proportions of the appeal dwelling and would not result in any significant harm to its character and appearance.

Overall, the proposed two storey extension would merge effectively with the style of the appeal dwelling and appear complementary to its original design and period. The set back of the first floor and the position of the side dormer would result in the proposed side extension appearing as recessive and secondary additions, which would result in it appearing as subordinate to the original appeal dwelling.

The neighbouring maisonettes at [address] sit significantly closer to the street than the appeal dwelling. This spatial relationship and the original gap between the appeal dwelling and this neighbouring property at first floor level, results in a clumsy and incongruous spatial relationship between the two.

The proposal would infill this gap at first and roof level, lessening the effect of this existing poor design relationship. This would result in the extended appeal dwelling appearing as a well-designed element within the street frontage and, as such, to make a positive contribution to the character and appearance of the local area.

For these reasons, the proposal would accord with Policies CC1, CC2 and SC7 of the Hounslow Local Plan 2015-2030 (2015). Amongst other matters these seek development, including by extension, to that is of high quality urban design and architecture and that creatively respond to the areas character, do not harm the existing character and appearance of the building and its context, complementing the original building and harmonising with neighbouring properties.

I have had regard to the Council’s suggested conditions should I allow this appeal. I have not included the suggested condition regarding the future creation of openings in the side elevation, as there are no exceptional circumstances that have been brought to my attention that would justify the removal of any permitted development rights. There are therefore no planning reasons that would make such a condition necessary.

Along with the standard condition regarding the timing of implementation, in the interests of good design I have attached conditions requiring compliance with approved plans and matching materials.

The appeal is allowed.