Appeal 3300048

The appeal is allowed and planning permission is granted for demolition of the existing conservatory and construction of a single storey rear extension at [site address] , Brentwood [postcode] in accordance with the terms of the application, Ref 22/00129/HHA, dated 24 January 2022, 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 following approved plans: location plan, block plan, 1812/22.

The materials to be used in construction of the external surfaces of the development hereby permitted shall be carried out in accordance with the approved plans to match materials existing on the dwelling.

Since the issue of the decision notice, the National Planning Policy Framework (the Framework) has been updated (September 2023) but the chapter and paragraph numbers and content of those paragraphs has not changed.

The main issues are: (a) Whether the proposal would be inappropriate development in the Green Belt having regard to the Framework and any relevant development plan policies, (b) The effect of the proposal on the openness of the Green Belt and (c) Whether any 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.

[site address] is a two-storey detached house in a line of detached dwellings on the western side of [site address] . It has a long back garden which includes two substantial historic outbuildings. The ‘stable block’ is some 5m from the conservatory to be demolished and straddles the boundary with [address], the adjacent dwelling to the south. Beyond this alongside the southern boundary is an elongated building about 20m in length, known as ‘the cow shed’. The site and surrounding area are within the Metropolitan Green Belt.

The proposed extension would be a new building. The Framework at Paragraph 149 states that the construction of new buildings should be regarded as inappropriate in the Green Belt, but cites an exception to this, at (c) “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”.

The Council’s Policies GB1 and GB2, quoted in the decision notice, pre-date the Framework and attract little weight. Policy MG02 of the Brentwood Local Plan (2016-2033) (BLP) states that “planning permission will not be granted for inappropriate development in the Green Belt other than in very special circumstances” and that “all development proposals within the Green Belt will be considered and assessed in accordance with the provisions of national planning policy”. Policy MG02 is therefore consistent with the Framework.

[site address] has been enlarged since the 1960s by a single storey side extension, a porch and first floor extension and by the rear conservatory. The Council have estimated the floor area of the original dwelling to be 69.[address] metres and the total now proposed, including previous additions, to be 165.[address] metres, equating to an increase in floor space by 138%.

The appellant refers to a photograph showing a single storey extension to the southern side of the dwelling in the 1930s. Even if the present side extension is an original feature, this would not substantially reduce the overall increase in the dwelling’s size. The appellant contends that the considerable size of the ‘cow shed’ and ‘stable block’ should be considered in the calculations. These are outbuildings that would have existed in 1948, the date from when the size of the original building should be determined. But the Framework is clear that it is the cumulative total of existing and proposed additions to the dwelling that should be the basis for comparison with the size of the original dwelling.

My findings are that the proposal would result in a disproportionate addition over and above the size of the original building. The proposal would therefore amount to inappropriate development. Paragraph 148 to the Framework states that substantial weight should be given to any harm to the Green Belt.

The Framework states at Paragraph 137 that “the essential characteristics of Green Belts are their openness and their permanence”. Openness has spatial and visual aspects. In relation to spatial considerations, the proposed extension would be a little deeper than the conservatory it would replace. A hot tub on the patio would also be removed. The appellant has estimated the extension’s floor area would only result in an additional [address] metres, mainly infilling between an existing utility room extension and the conservatory.

Similarly, in relation to the visual consideration, the extension would largely occupy the same space as the present conservatory. As it would be at the back of the house, it would not be visible from [site address] or from any other public viewpoint. The presence of outbuildings and high vegetation would screen it from adjacent dwellings and gardens. The visual impact would be negligible.

Having regard to combined spatial and visual considerations, the extension’s impact on the openness of the Green Belt would only be marginal. Nonetheless, the extension would still amount to inappropriate development.

Framework Paragraph 148 states, “Very special circumstances will not exist unless the potential harm to the Green Belt, by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations”. The Council has not outlined any other harm arising, such as in relation to the effect on the amenities of adjoining occupiers or on the character and appearance of the area. I have no reason to disagree.

The appellant claims energy efficiency as a reason for the proposal pointing to the conservatory’s very poor insulating properties. The claim is plausible, but sustainability improvements alone would not overcome harm to the Green Belt.

The appellant has also presented a fallback alternative should the appeal be dismissed. A single storey rear extension to a depth of 8m across the full width of the dwelling could be erected under permitted development allowances. [name].1.(g) to Schedule 2 to the General Permitted Development (England) Order (2015) (as amended) confirms this.

In my judgement, there is a greater than theoretical possibility the fallback would be implemented. An alternative plan has been prepared. It would cover substantially the same area as the appeal proposal but would have a greater depth. There is a real prospect that a permitted development rear extension would be built should the appeal be dismissed. As its greater mass would be more harmful to the Green Belt, the fallback is a material consideration that attracts considerable weight.

I have found the proposal to amount to inappropriate development. However, the permitted development fallback would result in a larger extension with greater harm to the Green Belt. Accordingly, the harm resulting from the proposal is clearly outweighed by other considerations and very special circumstances therefore do exist. The proposal would thereby be compatible with BLP Policy MG02 and with the Framework. For these reasons I conclude that the appeal should be allowed.

The only conditions necessary are those suggested in the Council’s appeal questionnaire to limit the lifespan of the permission to 3 years, to list the plan numbers in the interests of certainty and to require matching materials to ensure a satisfactory appearance.