Appeal 3266022

The appeal is allowed and planning permission is granted for Two storey side/rear extension, 1x side and 1x rear dormer windows, and alteration to fenestration at [site address] , in accordance with the terms of the application, Ref 20/01936, dated 29 July 2020, and the plans submitted with it, subject to the following

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 plans: 1151.05 [name], 1151.06.

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

The Council altered the description of the development from “proposed two storey rear extension” to “Two storey side/rear extension, 1x side and 1x rear dormer windows, and alteration to fenestration”. This is also the description used by the appellant on the appeal form. I consider this to be a more accurate description of the appeal proposals and I have therefore considered the appeal on this basis.

The main issue is whether the proposal would be inappropriate development in the Green Belt having regard to the revised National Planning Policy Framework (The Framework) and any relevant development plan policies. Appeal Decision APP/ T0355/D/20/3266022

The Framework states that development within the Green Belt is inappropriate unless it falls within one of the exceptions set out in paragraphs 145-146 of the revised Framework. These exceptions include the extension of a building, so long as this would not result in disproportionate additions over and above the size of the original building. Policy GB4 of the Royal Borough of Windsor and Maidenhead Local Plan (2003) (the Local Plan) reflects the Framework, stating that proposals for extensions to existing dwellings will only be permitted where the extension would not cause a disproportionate addition over and above the size of the original dwelling. The supporting notes to this policy says that a disproportionate addition could occur through one large extension or through the cumulative impact of a series of small ones.

Policy GB4 goes on to explain that the size of the extension relative to the original dwelling is an important consideration. In the supporting text GB4 clarifies that each case would be considered on its own merits, taking into account five factors including the original house size, plot size, nature of the surrounding area, design and position of the extension in relation to the view from public places (especially the appearance from the road), and the history of development at the site. This text also says that floorspace will be a guiding factor in assessing whether a proposal is in accordance with the policy, however, percentage increases are not the sole determining factor. The text finishes by confirming that the bulk and scale of the proposals, their effect on the openness and the purposes of the Green Belt and their impact on the general appearance of the area as well as the individual property will all be considered in assessing a proposal.

The proposed development would introduce an extension to an existing single storey element to the side of the house, making use of the existing rooflines and including dormer window elements to provide bathrooms to the first floor. The Council says that the proposed extension would result in an additional 22.[address] metres of floorspace, which would result in the total cumulative floorspace additions to approximately 132.[address] metres. The original dwelling was approximately 166.[address] meters, and the Council calculates that the proposed development would increase the original dwelling by about 79%.

I accept that, as a result of the proposal, the cumulative increase in floorspace to the original dwelling would be relatively large in terms of percentages. Nonetheless, the proposal before me is a modest addition to the house, and the proposal would not protrude beyond the main walls of the dwelling. Therefore, whilst I accept that the cumulative increase in floorspace over the original dwelling would be extensive, I consider that the proposal would not be a significant addition and would result not be of dissimilar size to nearby properties along [address].

The plot for the host dwelling is large and spacious, with the house being set well back from the lane, with generous spacing to the side boundaries. The footprint of the dwelling would not be increased and whilst the development would introduce new elements, the extension would remain below the main ridgeline of the house and the dormer windows would reflect the existing dormer windows. The design and materials are proposed to match those of the existing dwelling, including reflecting the gable features seen throughout the Appeal Decision APP/ T0355/D/20/3266022 house. I note that the Council consider that the proposal would complement the main roof design and would respect the character and appearance of the host dwelling. The dwelling is set well back from the road, in an elevated position with significant mature vegetation to the front garden area. In addition to this, the extension would be located to the side of the dwelling behind the existing roofslope and would not be easily seen from the road.

Taking into account my findings above, particularly in relation to the scale and siting of the proposal, I consider that the development would not cause harm to the openness of the Green Belt or the character and appearance of the area. I also find that the proposal would not conflict with any of the purposes of the Green Belt, as set out in paragraph 134 of the Framework.

Notwithstanding that the proposal would lead to a substantial cumulative increase in floorspace over the original dwelling, I find that, due to the large plot size combined with the scale, siting and design of the proposed extension and that it would not be easily visible from [address], the proposal on balance, does not represent a disproportionate addition to the original dwelling. Therefore, the proposal does not conflict with Policy GB4 of the Local Plan and should not be considered as inappropriate development within the Green Belt as described by the Framework.

As well as the time limit condition, I have specified the approved plans for certainty. In the interests of character and appearance, I have imposed a condition requiring that all external facing materials match those on the existing building.

For the reasons set out above and subject to the conditions attached, I allow the appeal.