Appeal 3365377

The appeal is dismissed.

An application for costs was made by [name] against Welwyn and Hatfield Borough Council and this is the subject of a separate Decision.

The main issues are: • whether the proposal would be inappropriate development in the Green Belt having regard to the National Planning Policy Framework and any relevant development plan policies; • the effect of the proposal on the openness of the Green Belt; and • if the proposal is inappropriate development, whether the harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations so as to amount to the very special circumstances required to justify the proposal.

The appeal property lies within the Metropolitan Green Belt. The Framework states that development in the Green Belt is inappropriate unless it is for one of a defined exceptions listed in paragraph 154. The appellant and the Council have referred to a number of matters that relate in some way to these exceptions.

Part (c) of paragraph 154 of the Framework affords for the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building. ‘Original building’ is defined in the Glossary of the Framework as a building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally.

Policy SADM 34 of the Welwyn Hatfield Borough Council Local Plan 2023 sets out the same policy approach as the Framework, requiring any extensions and alterations to a building in the Green Belt to demonstrate there will not be a disproportionate addition over and above the size of the original building in terms of bulk, scale, height or massing. The Policy says that account will be taken of the extent to which an extension would be consistent with the general pattern of development and character of the area and its prominence within the landscape.

Paragraph 24.10 of the supporting text to Policy SADM 34 provides further guidance on how the Council will determine what would constitute a disproportionate extension to a building. This says that a quantitative and qualitative assessment will be undertaken and, in quantitative terms, proposals that would result in the footprint, volume and/or above ground external dimensions of a building being 50% greater than the original building would generally be refused.

The property is a detached house on a large plot, lying in an area characterised by dwellings also set on large plots. The building has been extended a number of times since it was originally constructed. The Council have calculated that the proposals in this appeal would result in a cumulative increase in floor area of 179% over the original building, which is not disputed by the appellants.

This is a substantial increase and is significantly beyond the quantitative guideline of 50% contained in the Local Plan. The scale of this proposed increase over the original would be clearly manifested on site: the extensions would create a very sizeable addition to the rear of the property through the two storey rear extension and the single storey extension, adding to the scale, bulk and massing of the building. The front extension to the property would further add to bulk and scale of the building.

Taken together, the proposed extensions would represent a significant increase in the bulk and massing of the property. This would represent a sizeable addition to the already enlarged building. Together with the previous extensions it is apparent to me the original building would be very significantly increased in volume and scale. This size and scale would represent a clearly disproportionate addition to the original building.

Accordingly, the proposal does not fall within the exception at paragraph 154(c) of the Framework.

The appellant contends that the proposal should be considered as limited infilling within a village under part (e) of paragraph 154 of the Framework. Policy SADM 34 sets out that limited infill development will be permitted in villages within the Green Belt subject to four provisos.

The matter of whether the property can be considered as lying within a village was considered at a recent appeal concerning the property in July 2023 (ref. APP/C1950/D/21/3289534). I concur with the findings in that appeal that the site is not within a village, due to the physical and visual separation between the site and the village of Welwyn due to intervening open land, including Danesbury Park.

Moreover, the supporting text to Policy SADM 34 explains at paragraph 24.14 that limited infill is defined as development within an otherwise substantially built up road frontage within the built up area of a village, for example filling a narrow gap between buildings or the redevelopment of an existing property. The proposed development does not propose this form of development as it is for an extension to the rear and to the front of the existing building; there is no infill of any road frontage or gap. My finding on this is consistent with the previous Inspector’s comments that the ordinary meaning of the word ‘infill’ implies filling in a space between two pre-existing things. There is no such infilling occurring.

The appellant has drawn attention to an appeal decision in St Albans City and District Council (ref. APP/B1930/D/20/3261569) where a single storey side extension was found to constitute limited infilling in a village. In that case the appeal property lay within a village as defined in the local plan, and the extension was to the side and so would be partly closing a gap between two buildings. Those two matters do not apply in the current appeal, and so the case is not comparable.

The appellant further contends that the proposed development would accord with part (g) of paragraph 154 of the Framework. This allows for the limited infilling or the partial or complete redevelopment of previously developed land which would not cause substantial harm to the openness of the Green Belt.

The appeal site constitutes previously developed land. However, the proposals are not for partial or complete redevelopment of the land: the existing building is retained and extensions shown to that building. The proposal was described in these terms in the description of the development on the application form, and the drawings show extensions to the existing building being retained rather than works which constitute any redevelopment of the land.

In my view it is clear that the proposal is for extensions to an existing building, and hence falls to be considered under part (c) of paragraph 154 of the Framework. I have found earlier that the size and scale of the proposed development would represent a clearly disproportionate addition to the original building and so does not fall within the exception of part (c). The proposal would be inappropriate development that is, by definition, harmful to the Green Belt and in conflict with the Framework and Policy SADM 34 of the Local Plan.

The Framework states that the fundamental aim of Green Belt policy is to prevent urban sprawl and keep land permanently open, and that the essential characteristics of Green Belts are their openness and permanence. It has been established that openness has both a spatial and visual aspect.

The proposed extensions would be sited to the rear of the appeal property, in a site that benefits from an element of natural screening due to mature trees and vegetation. Nevertheless, from a spatial perspective it would lead to a material reduction in the openness of the Green Belt by adding a sizable volume of built form to the property.

The siting and scale of the proposed development would directly contravene the purpose of the Green Belt and harm openness.

The design of the extension would reflect the host property through the use of matching materials, and would be distant from neighbours. Thus, there would be no harmful effect on the character of the area or on residential amenity.

The proposal is to provide an extension to a private home, providing additional space for living and home working. I attach limited weight to this personal circumstance.

The proposal is inappropriate development in the Green Belt and it would result in harm to openness. The Framework states that substantial weight should be given to any harm to the Green Belt, including harm to its openness, and should not be approved except in very special circumstances. The Framework further advises that ‘very special circumstances’ to justify inappropriate development will not exist unless the harm by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations.

I do not consider the matters raised in support of the proposal to clearly outweigh the harm identified. Consequently, the very special circumstances necessary to justify the development do not exist.

For the reasons given, the conflict with national and local planning policy means that the appeal should fail.