Appeal 3328352

The appeal is dismissed.

There are four main issues. Firstly, whether the proposed extensions would amount to inappropriate development in the Green Belt, having regard to the National Planning Policy Framework (the Framework) and any relevant development plan policies; secondly, the effect of the proposed extensions on the openness of the Green Belt; thirdly, the effect of the proposed two storey side extension on the character and appearance of the host dwelling and the surrounding area, and fourthly, if the proposed extensions would amount to inappropriate development, whether the harm, by reason of inappropriateness and any other harm is clearly outweighed by other considerations, such as to amount to the very special circumstances necessary to justify the development.

Since the Council determined the original application, the Welwyn Hatfield Local Plan 2016-2036 (LP) has been adopted on 12 October 2023. The policies contained in the Welwyn Hatfield District Plan 2005 and referred to in the Council’s refusal notice have therefore been superceded by newly adopted policies. The relevant new policies were referred to (as emerging policies) in the refusal notice. Parties have not therefore been prejudiced and I have had regard to the new policies and in particular SP9 and SADM34 in my determination of the appeal.

Since the application was determined, a revised National Planning Policy Framework (Framework) was published in December 2023. However, as any policies that are material to this decision have not fundamentally changed, I am satisfied that this has not prejudiced any party. I have had regard to the latest version of the Framework and new paragraph numbers in reaching my decision.

The appeal site is located on the edge of the rural settlement of Burnham Green. It lies within the Green Belt. The site comprises a detached dwelling with a large, single storey side extension on the northeast elevation. The dwelling sits close to the northeast boundary of its large plot which adjoins open countryside to the northwest. The Council estimates that the original dwelling had a footprint of some 86sqm and that existing extensions have added a further 74sqm. This is not disputed by the appellants.

The proposal is to demolish the existing extensions and add a two storey extension over part of the same footprint. In addition, single storey extensions would be added to the northwest and southwest elevations of the original dwelling. The Council estimates that in total the additions would result in an increase in footprint of some 77sqm. Whilst that is similar to the existing extensions to be removed, there would be a first floor element which would result in an overall larger volume .

Policy SADM34 of the LP states that within the Green Belt, planning permission will be granted for development in accordance with national policy and other policies in the LP subject to a range of criteria. For extensions and alternations, these should not result, either individually or cumulatively, in disproportionate additions over and above the size of the original building in terms of bulk, scale, height or massing. “Original building” is defined as a building as it existed on 1 July 1948 or as originally built if after that date. This is consistent with the exceptions set out under paragraph 154 of the Framework. The explanatory text to Policy SADM34 suggests that as a starting point an increase in footprint, volume and/or above ground external dimensions more than 50% greater than the original building is likely to be disproportionate. Notwithstanding the removal of existing extensions, the proposed increase in footprint and by extension volume, which would be well in excess of 50% would therefore be disproportionate.

It is concluded on the first main issue that the proposed extensions would amount to inappropriate development in the Green Belt. The Framework advises that substantial weight should be given to any harm to the Green Belt, including that by reason of inappropriateness.

The Framework states that the essential characteristics of Green Belts are their openness and permanence. The proposed extensions would be noticeable from Harmer Green Lane and from the open countryside. They would increase the bulk of the building and whilst this would, in part, be offset by the demolition of existing structures I consider that there would still be a modest loss of spatial and visual openness given the larger volume of the proposed extensions than 2 currently exist. However, I agree with the Council that they would not conflict with any of the purposes of Green Belts set out in the Framework. 10.It is concluded on the second main issue that the proposed extensions would result in modest harm to the openness of the Green Belt. This harm attracts substantial weight.

In terms of design, the Council raises no objection to either of the two proposed single storey extensions and I agree they would sit comfortably with the host dwelling in terms of scale and appearance, responding positively to the character and context of the original dwelling, in conformity with LP Policy SP9. 12.However, the proposed two storey extension would be of starkly contemporary design and would be prominent in the street scene. It would not reflect either the architecture or proportions of the original dwelling. In particular, it would be a flat roofed, boxy extension and whilst alternative design should not be rejected simply because it is different, it is still necessary for it to form a sympathetic addition to the host dwelling. 13.In this case its height would mean that the flat roof would sit above the existing eaves level, creating an awkward juxtaposition with the original eaves and with the shallow pitched roof. In particular, it would cut across the eave and cut into the roof about half way up the slope. This would give it a disjointed and ill-proportioned appearance. The proposed vertical wood cladding would emphasise the height, adding to the incongruous appearance. Moreover, whilst there is no architectural uniformity or distinctive form or design in the surrounding area, I did not see any examples of flat roofed buildings or extensions above ground floor in the vicinity of the appeal site. 14.The appellants suggest that the original dwelling has a strong vertical emphasis and that the extension would respond to this. However, the original house with its long, narrow footprint, shallow pitched roof and arrangement of glazing in the southwest elevation, serving the main habitable areas, has a noticeably horizontal emphasis which is reflected in the existing single storey side extensions. New vertical wood cladding to match that proposed for the two storey extension would be added to some parts of the original dwelling and proposed single storey extensions. However, this would not alter the original form of the dwelling or the proposed extension and would be insufficient to coordinate the two elements. The appellants provide a number of examples of other contemporary design and similar wood cladding on other dwellings, but these do not appear to be nearby. Moreover, I do not find them readily comparable with the appeal situation.

It is concluded on the third main issue that the proposed two storey side extension would have a materially harmful effect on the character and appearance of the host dwelling and the surrounding area. In consequence, it would conflict with LP Policy SP 9 and with the Framework which, taken together, expect extensions to be of a high quality design that responds positively to the character and context of the original building and local area in an integrated and coherent way. This harm carries significant weight. 3 Other considerations 16.The appellants draw my attention to one other consideration which they consider might amount to the very special circumstances necessary to justify the proposal. This is the existence of a fallback position. The Council has recently granted Lawful Development Certificates (LDCs) for both a larger single storey side extension to the southwest elevation and a two storey extension to the northwest elevation. There is broad agreement regarding the size of the original dwelling and existing extensions since original plans are available. 17.The appellants calculate that the permitted development additions, which I consider to represent a genuine and realistic fallback, would add about the same to the floor area and volume of the original dwelling as the proposed extensions before me now. Moreover, I note that whilst under the appeal scheme the existing single storey extensions would be demolished, this is neither proposed nor necessary in the context of the proposals subject to the LDCs. Therefore, the LDC additions would be over and above the existing extensions and not in place of them. Overall, the fallback would lead to a noticeably larger dwelling that would have a greater effect on Green Belt openness than the appeal proposal. 18.Nevertheless, I have found that the proposed two storey extension would have a materially harmful effect on the character and appearance of the host dwelling and the surrounding area and that this harm would carry significant weight against the proposed development. By contrast, the LDC proposals would be of more conventional design and would harmonise with the host dwelling and would be preferable in that respect. 19.Overall, given that the fallback would have a greater effect on Green Belt openness, I therefore find that it would carry moderate weight in favour of the appeal proposals. 20.In addition, I accept that the better layout provided by the appeal proposals would improve the property in terms of living accommodation, which carries limited weight in their favour. 21.In the final balance, the fallback position and improved layout would not therefore clearly outweigh the total harm to the Green Belt, through inappropriateness and effect on openness, and the further harm to the character and appearance of the area caused by the appeal proposals. 22.Accordingly, it is concluded on the fourth main issue that, looking at the case as a whole, the other considerations would not clearly outweigh the identified harm to the Green Belt and the other harms. Consequently, the very special circumstances necessary to justify the development do not exist. The proposed extensions would therefore conflict with [name] SADM34 and SP9 and with national policy set out in the Framework. 23.For the reasons set out above and having regard to all other matters raised, I conclude that the appeal should be dismissed.