Appeal 3356801

The appeal is allowed and planning permission is granted for dormer extensions, floor plan redesign and all associated works at [site address] , Chiswick, Hounslow, London [postcode] in accordance with the terms of the application, [name]/2024/2316, 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: 224994/PR/3100.

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 window to the en-suite bathroom in the rear elevation of the development hereby permitted shall at all times be obscure glazed and non-opening below 1.7 metres above internal floor level.

Subsequent to Council’s decision, the Government published a revised National Planning Policy Framework (December 2024) (the Framework). I consider that there have been no major changes relevant to the main issues in this appeal. It will therefore not prejudice any party by making my decision with regard to the revised Framework.

The main issue is the effect on the character and appearance of the appeal dwelling and that of the local area, with reference to the [address] Conservation Area (the CA).

The appeal dwelling is an attached two storey house with front feature attic gable and relatively complex hipped roof forms, which is within a local area made up of a mixture of closely set detached, semi-detached and terraced properties. This is located on the West side of the CA, the Significance of which largely rests in its high quality Victorian architecture and wide range of house types and the resultant largely small human scale suburban townscape it creates.

In line with the duty imposed on me by section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, I have given considerable importance and weight to the desirability of preserving or enhancing the character or appearance of the CA.

The proposed wraparound dormer would be centrally positioned on the rear roof slope, which has a roof ridge that steps down towards the attached neighbour at [address] (No.34). The proposal would step down from the tallest part of the roof ridge, be set in from the edges of the roof and up from the eaves. The proposal would wrap around where the roof ridge steps down and would continue around to replace an existing single side dormer window on the side hipped roof slope that faces towards No.134.

Given the set in positioning of the proposed dormer extension on the rear roof slope, it would appear as a proportionate and secondary addition, which from the rear would appear to reflect the wide variety of dormer extensions evident on the rear of houses in this immediate part of the CA. From the front street views the proposal would have a limited visual presence, due to its recessive location towards the inset between the appeal property and where it joins with No.134 and would fundamentally replicate the appearance of the existing side dormer window. As such I find that the proposal would appear as a secondary addition to the appeal dwelling that would not result in any significant detriment to its character and appearance and the contribution that it makes to that of the CA.

The Hounslow Character, Sustainability and [name] A5 [name] (2021) (the SPD), advises that roof extensions should not be the full width of the house and not wrap around two planes of the roof. However, the proposal is for an extension significantly less than the full width of the house, with a partial wraparound element that replaces existing rear and side dormer windows. This would be set within the existing complex hipped roof form and would be set down from the roof ridge and up from the eaves.

The SPD is guidance that needs to be applied with regard to the individual proposal and context, and I find that the proposal, whilst a wraparound roof extension, would meet the objectives of the SPD, in that it would be subservient to the size of the roof within which it would be set. As such, it would reflect the character and appearance of the appeal dwelling and that of the local area, and preserve the significance of the CA.

For the reasons given above, the proposal would not result in any significant harm to the appeal dwelling and that of the local area and would preserve the Character and appearance of the CA. This would accord with the Policies SC7, CC1, CC2 and CC4 of the Hounslow Local Plan 2015-2030 (2015. Collectively these seek developments, including extensions, that are 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, and conserve the significance of heritage assets.

I have had regard to the Council’s suggested conditions should I be minded to allow the appeal. Along with the standard condition relating to the timing of implementation, I have attached conditions to ensure design quality that require compliance with the approved drawings and materials that match existing. To protect privacy, I have included a condition requiring obscured glazing to the window to the proposed en-suite bathroom.

For the reasons given, the appeal is allowed