Appeal 3270771

The appeal is allowed and planning permission is granted for first floor extension at the rear of the property, extend existing hip roof and install new conservation rooflight and lantern light to existing single storey extension at [site address] , Mortlake, London [postcode] in accordance with the terms of the application, Ref 20/3480/HOT, dated 4 December 2020, and the plans submitted with it, subject to the following conditions:

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

No new external finishes (including fenestration), including works of making good, shall be carried out other than in materials as submitted.

The development hereby permitted shall be carried out in accordance with the following approved plans Drawings 1536.01; and 1536.02.

The main issue is the effect of the proposed first-floor rear extension on the character and appearance of the host property, the Mortlake Conservation Area and the nearby Buildings of [name].

[site address] (No.5) is one of a pair of semi-detached houses (with No.[address]) on the eastern side of [address]. No.5 is accessed only by foot from [address] which runs between [address] and [name]. No.5 is within the Mortlake Conservation Area (CA) and is identified by the Council as a Building of [name] (BTM).

In accordance with the statutory duty imposed by section 72(1) of the Planning (Listed Building and Conservation Areas) Act 1990, I am required to have special regard to the desirability of preserving or enhancing the character and appearance of the CA. This part of the CA is principally characterised by the narrow path of [address], which provides a secluded and intimate setting for the attractive pairs of semi-detached cottages. Part of the character is derived from the appearance of the front elevations of the cottages, with arched windows, set behind generous front gardens. The rear elevations of houses on [address] are not visible from the public realm, only seen from a small number of terraced houses that front [address], and make a very limited contribution to the character or appearance of the CA.

No.5 sits to the rear of its plot. There is an existing ground floor extension up to the rear boundary and a courtyard garden and detached garden office to the side. The proposal is to extend at first-floor level by around 1.95m from the rear elevation over the full width of the house, extending the hipped roof and incorporating a dormer to improve the internal headroom of two bedrooms. The proposed dormer extends only part of the width of the rear elevation and would have a section of flat roof, which I recognise is not a form typical of the area or reflects the existing roof profile of No.5. However, the scale of the flat roof would be relatively limited and has been designed so that it aligns with the eaves of the original building. Combined with the extension to the hipped roof, it would not appear unsympathetic to, or dominate, the existing roof and its original profile would still be legible and appreciated.

I note that the extension is proposed to be finished in render, rather than the yellow stock brick construction of the original house, but I consider this an acceptable way to distinguish between the old and new that would complement the modern ground floor extension. The existing style and pattern of windows on the rear elevation will would also be replicated, albeit the window closest to the party wall with No.6 would be larger. I do not therefore find that the proposed extension, even in combination with the existing ground floor extension, would appear incongruous or detract from the intrinsic character of the original house as a of BTM.

Because of the siting of the host house at the rear of its plot, the extension would not be particularly visible even from the garden of No.5 itself. There would be very limited views of the rear corner of the extended roof from [address] but I am satisfied that there would be no material change to the appearance of the house from the public realm and no harm to the character and appearance of the [name] have described above.

The Council have referred in their decision to the proposed development having a negative impact on nearby BTMs. I have not been provided with any information regarding nearby BTMs, nor am I aware of any, save No.[address]. However, given my conclusions regarding the absence of harm to the host house and CA and I am not persuaded that there would be a significant impact on other nearby houses, in terms of their character and appearance.

I therefore conclude that the proposed development would preserve the character and appearance of the host house, the [name], and the surrounding area in general. Consequently, there would be no conflict with Policies LP1, LP3 and LP4 of the Local Plan (2018) which seek to ensure developments are a high quality of design, compatible with local character, including existing townscape, and would preserve the character and appearance of the CA and BTM. There would also be no conflict with the guidance in the Local Plan Supplementary Planning Document: [name] and [name] (2015) because the extension would not dominate the original roof and would be sensitive to the existing character.

I have imposed a standard condition relating to the commencement of development and a condition specifying the relevant plans as this provides certainty. To safeguard the character and appearance of the area I have imposed a condition concerning materials.

The Council have suggested a condition restricting any part of the roof hereby approved to be used as a balcony or terrace. The extent of the flat roof is very limited and its location relative to the hipped roof means that it is far from accessible. I do not therefore find such a condition to be necessary.

The Council have also suggested conditions relating to the type of equipment or vehicles used during onsite construction and the submission, approval of a fire safety strategy. Given the modest scale of the proposed extension, I do not consider that the planning permission should be dependent on such restrictions or requirements, and they are not necessary in planning terms.

For the reasons given above, I conclude the appeal is allowed.