Appeal 3293967

The appeal is allowed and planning permission is granted for single storey rear infill extension and alterations to fenestration at [site address] in accordance with the terms of the application Ref: 21/2100/HSE dated 23 October 2021 and the plans submitted with it, subject to the following

The works authorised by this consent 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: 21/0639/02; 21/0639/0621/04; 21/0639/05; 21/0639/06; 21/0639/07.

Prior to the commencement of development here approved detailed drawings at a scale of 1:50 or larger, shall be submitted to, and approved in writing by, the local planning authority. These drawings shall give sufficient detail by section, plan and elevation, to demonstrate that the completed single storey rear extension can be erected such that no part of that extension other than the rooflight shown on the approved drawings is higher than 2.95m above floor level. The development shall proceed in accordance with the approved drawings.

The roof of the extension hereby approved shall not be used for sitting out or accessed other than for the purpose of maintenance and repair.

In the interests of clarity and certainty I have used the description employed on the Council’s decision letter rather than the brief form on the application.

The main issue is the effect of the proposed development on the living conditions of neighbouring users.

[site address] (No.9) sits within a quiet suburban road of substantial detached houses of varied design set within large plots. Both the appeal property and its neighbours have been extended in different ways and benefit from extensive open garden areas at the rear with an open south-western aspect.

The proposal would extend the ground floor accommodation by 3.95 metres from the current main rear wall such that it infills between a rear wing and the line of flank wall of No.9 on the side adjacent to No.[address] (No.7). The drawings submitted indicate that there would be an overall reduction in the height of the extension from, and including that found in, the current rear extension by something over 50cm to 2.95m.

The Council identify a conflict with Policy 30 of the Site Allocations and Development Management Policies Plan 2016 (SADM) and with the Councils Planning and [name] (Design Guidance) and allude to previous appeal decisions albeit for proposals which differ to a material degree. The current rear extension falls within the line of a 45-degree splay from the nearest ground floor window of the adjacent house, No.7 and this would conflict with EKP-1 of that guidance.

Design Guidance such as this is important in providing a consistent approach to determining proposals for residential development where this could impact upon visual amenity or living conditions and is, therefore, a consideration to which weight should be attached, albeit to a degree that has regard to the circumstances being considered.

The guidance refers to a 45-degree splay line from habitable rooms but impact of such intrusion would clearly reduce or increase according to the relative heights of the buildings involved. The new flank wall would be below that of the current extension by around one half-metre such that any enclosing effect by virtue of height would be less than that which is currently experienced.

Similarly, the open south-western outlook of No.7 suggests that the kitchen window of No.7 would continue to receive direct sunlight because of its orientation relative to the proposed extension and, for the same reason, there would be no measurable impact on access to daylight. In my view, the reduction in the height of the existing extension, which is close to the affected window, would lessen the effect of the existing development and, on balance, offset any perception of greater enclosure from the additional length of the flank wall of the proposal. From my observations and notwithstanding the conflict with the guidance referred to, in these specific circumstances the proposal would not unacceptably harm access to daylight, sunlight or have an overbearing effect on the neighbouring user.

I therefore conclude that there would be no conflict with Policy 30 of the SADM which seeks that development should achieve a high quality design which has limited impact on the amenity of occupiers and neighbours or with [name] of Hertsmere’s Planning and [name] having regard to the circumstances here considered. On that basis the proposal would accord with the development plan taken as a whole and, taking all matters into account and for the reasons given, it follows that the appeal should succeed.

In addition to the usual time limit, conditions are necessary to ensure the development is carried out on the basis by which I have reached my conclusions and that would require not only a plans condition but, noting the wide spans shown, a requirement to submit a detail drawing to demonstrate the proposed extension can be constructed within the prescribed height limit. In addition, although no party has raised this issue, I consider a condition preventing the use of the flat roof as a terrace would be appropriate to protect adjoining users from overlooking.