Appeal 3373123

The appeal is allowed and planning permission is granted for part single / part two-storey rear extension, first-floor side extension above existing garage, new roof with front and rear dormer windows to allow for second floor accommodation (existing ridge height to be retained) and internal alterations at [address], [site address] , Buckinghamshire, [postcode] in accordance with the terms of the application, [name]/25/1778/FA, 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.

The development hereby permitted shall be carried out in accordance with the approved plans: [name] SO1, D10-A, D11-D, D12-D, D13-D and D20-D.

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

The banner heading above quotes the description of development that was given on the application form. This was largely repeated on the Council’s decision notice but without reference to the past consent.

The appeal property has been the subject of two recent planning permissions. [name] 2024 permission was granted under [name]/24/0981/FA for development described as ‘Part single / part two storey rear extension, first floor side extension above existing garage, new roof with rear dormer windows to allow for second floor accommodation (existing ridge height to be retained) and internal alterations’ (the original permission). [name] 2025 the Council granted permission [name]/25/0625/VRC for ‘Variation of condition 3 (approved plans) attached to pp PL/24/0981/FA (part single/part two storey rear extension, first floor side extension above existing garage, new roof with rear dormer windows to allow for second floor accommodation (existing ridge height to be retained) and internal alterations) to allow for design alterations’. I have been provided with copies of both decisions, all the approved plans, and the Council’s officer’s reports for both applications.

The appeal proposal was submitted as a full planning application for further amendments to the approved scheme, incorporating those that were permitted as a variation to the original permission. These comprise an extended depth to the rear of subservient, two-storey wings either side of the dwelling’s original core with a commensurate rise to their ridge heights, and two dormer windows to the front roof slope.

At the time of my visit, I observed that some significant demolition works to the original dwelling had taken place but with little evidence of a substantive start for the approved extensions.

Given all of this background, I have considered the appeal as a proposal for the entirety of the works, including those previously approved, but with the further amendments included. The description of development in my formal decision reflects this approach and uses only a slightly altered form of words to those on the original planning permission in order to include reference to the front dormer windows.

The main issue is the effect of the proposal upon the character and appearance of the area with specific regard to an increased depth by 1m to a part first-floor extension and two front dormer windows.

The appeal relates to a two-storey, detached dwelling to the south side of [address] within a residential neighbourhood identified within the Chiltern and [name] 2017 (TCS) as a "Woodland Road" character typology area comprising typically large detached houses within large plots in a mature woodland landscaped setting. Planning permission exists, and remains extant, to significantly remodel the original dwelling to one of greater scale and bulk, including with accommodation at second floor level in part of the roof space with dormer windows to the rear.

In this instance, despite the slightly raised ridge height to each side wing resulting from the proposed increased depth of these elements, both would remain obviously subservient, being set down in height from the dwelling’s main roof, thereby maintaining a break in its overall roofscape. As previously accepted by the Council, this would help to reduce the building’s dominance within the street scene. The marginal height increases to each side would not add any significant bulk.

I note the TCS identifies, amongst other things, two-storey buildings with a large area of additional accommodation in the roof as a potential threat to the character of the area. Concern here rests with the potential for a building to dominate over the landscaping. As a design principle, the TCS goes on to state that building heights should be limited to two storeys, including accommodation in the roof.

The proposed front dormers would not create any significant additional floorspace in the roof over that already permitted. The expanse of accommodation at this level would remain limited in size and contained within the central core of the dwelling, which would remain obviously two-storey in scale and height, but with use of the roof space becoming apparent as a result of the front dormers.

Although not common, front dormers are not alien along [address]. Those proposed in this case would be modest in size and would sit comfortable within the front roof slope, being set up from the eaves, down from the ridge, in from the sides, and reasonably spaced in relation to each other. I find nothing about their presence that would be disproportionate or out of context with the appearance of the building. In this regard I am unable to detect any conflict with the Council’s Residential Extensions and Householder Development Supplementary Planning Document (2013) as far as it seeks to guide roof alterations.

The dwelling would remain set behind the plot’s frontage and the inclusion of dormers would have no impact upon any surrounding vegetation.

When all of this is considered, I am not persuaded that the modifications proposed to the previously approved development would make the dwelling any more dominant in its setting, and am satisfied that there would be no impact upon the woodland character of the area that would be either significant or harmful. As such, there would be no conflict with Policy CS20 of the [name] for Chiltern District, adopted in 2011, or with Policies GC1 and H18 of the Chiltern District Local Plan, adopted in 1997 (as altered and consolidated), which between them seek to ensure that development, including specifically dormer windows, displays a high standard of design that reflects and respects local character.

In the event of the appeal succeeding the Council has suggested three conditions. In addition to the standard time limit condition, a condition requiring the development to be carried out in accordance with the approved plans is necessary for the avoidance of doubt and in the interests of proper planning. A further condition is also necessary to ensure that the development is carried out in materials to match the existing in order to safeguard the character and appearance of the area. For the avoidance of doubt, these three conditions reflect in general the three conditions that were imposed upon the original permission, and then again on the second permission which varied the approved plans.

For the reasons given above, the appeal is allowed.