Appeal 3330099

The appeal is allowed and planning permission is granted for a roof alteration for a 2 storey side extension and first floor rear extension in accordance with the terms of the application Ref 29754/APP/2023/1806, dated 21 June 2023, subject to the following conditions:

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

The development hereby permitted shall be carried out in accordance with the following approved plans: 22006-WOODSIDERD17-701, 22006-WOODSIDERD17-702, 22006-WOODSIDERD17-703, 22006-WOODSIDERD17-705, 22006-WOODSIDERD17-706, 22006-WOODSIDERD17-708, 22006-WOODSIDERD17-802, 22006-WOODSIDERD17-803, 22006-WOODSIDERD17-805, and 22006-WOODSIDERD17-806.

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

The description of proposed development, as cited above, is taken from the application form. This wording makes sense in the context that this is an alternative scheme with a revised roof configuration for a 2 storey side extension that already has planning permission. The Council’s version on its decision notice is, however, more accurate in that it describes the whole of the development: “Erection of a double storey side and part first floor rear extension with new front door and amendments to fenestration”. I saw at my site visit that the extension has been built up to about wall plate level.

The main issue is the effect of the proposal on the character and appearance of the house, [address] and the [address] Estate Area of Special Local Character (ASLC).

[site address] is a large 2 storey detached house sitting on a sizeable plot within a residential area designated as an ASLC. The Council advises that this area was originally developed in the 1930s as a garden suburb, to designs by an architect who also worked on [name]. The houses here are varied in design, with well-articulated forms. They are laid out at a low density that allows for landscaping and helps to give the area a spacious, leafy character. No 17, one of the original 1930s houses, is typical of the area, though it is somewhat unusual in having its main entrance on the side.

The key difference between the approved extension and this appeal proposal is that there would be a crown roof over the side extension instead of this part of the roof being split into 2 hipped roof sections. The side extension is not as deep as the main house and this section of roof would be much lower than the main roof, so that the side extension would still be an appropriately subsidiary element of the overall building. Although this version would be a bit bulkier than the previously approved version, the front elevation would be little changed and the extension would be in character with the house and other nearby houses. The building would continue to remain proportionate to its large plot and the spaciousness of the area would be maintained.

I note that policy DMHD1 of the Hillingdon Local Plan Part 2 Development Management Policies (LP2) does not support the use of large crown roofs. Although the policy reference is specifically about crown roofs on rear extensions, it seems fair to consider it in regard to side extensions like this as well. In this case, however, the appellant has pointed out a number of crown roofs in the local area. My own observations at my site visit tend to confirm that crown roofs are a normal part of the area’s established architectural character. In these circumstances, I find no objection to the use of this design device in this particular case.

I conclude that the proposal would not harm the character or the appearance of the house, [address] or the ASLC. It accords with policies BE1 and HE1 of the Hillingdon Local Plan Part 1 [name], LP2 policies DMHB1, DMHB5, DMHB11, DMHB12 and DMHD1 and the National Planning Policy Framework, which taken together aim to secure high quality design that conserves and enhances Hillingdon’s distinct and varied environment, harmonising with the local context and reflecting the character of the ASLCs.

I have also considered the comments made by a local objector. In particular, I find that the houses to the rear of the site, which front onto [address], are more than far enough away from No 17 to ensure that the extension would not significantly affect neighbours’ privacy.

I impose a condition specifying the relevant plans to provide certainty and another requiring the use of matching materials to protect local character and appearance. I note that trees near to the extension are protected by a Tree Preservation Order. As the bulk of the proposed extension has already been built, however, I see no need for a tree protection condition at this stage.

For the reasons set out above, and having regard to all other matters raised, I conclude that the appeal should succeed.