How much exactly?

Q How much harm is less than substantial harm, exactly?

A More than 5.25 per cent.  

Paragraph 134 of the Framework states that ‘Where a development proposal will lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal…’. The question this raises, of course, is how much harm is less than substantial harm? An inspector dealing with an appeal against the refusal of planning permission for 290 dwellings on ridge and furrow earthworks in Leicestershire decided, in the case before him, that it was more than 5.25 per cent of the earthworks (DCS Number 200-007-416).

The inspector recorded that several parcels of the appeal site contained ridge and furrow earthworks. The appellant and county council agreed that they were a non-designated heritage asset. The majority of the earthworks fell within a ‘priority township’. The county council was of the view that the earthworks were of demonstrably equivalent significance to scheduled monuments and should therefore be considered subject to the policies for designated heritage assets, as set out by Paragraph 139 of the Framework. The appellant disagreed with this view, and the inspector also had some reservations, given that priority townships were not identified in English Heritage’s Scheduling Selection Guide for Agriculture, 2013 (reissued in 2015). However, given that he was allowing the appeal, he gave the county council the benefit of the doubt in order to take a precautionary approach. He therefore considered the proposal in line with policies for designated heritage assets.

The inspector agreed with the county council that the significance of the earthworks resulted from their largely coherent physical survival, group value, archaeological and historic research potential, diversity and amenity value. The proposal would result in the loss of some six hectares of earthworks within the priority township, he recorded. According to the county council the level of loss that would occur to the earthworks within the priority township as a result of the scheme was a 3.5 per cent loss if just the ‘well-preserved’ earthworks were taken into account or a 5.25 per cent loss, if the directly affected furlongs, which had a larger area of 7.8 hectares were considered.

The appellant referred to the Nuon High Court judgment (Bedford BC v SSCLG & Nuon UK Ltd [2013]), which states that substantial harm would be harm that would have such a serious impact on the significance of the asset that its significance was either vitiated altogether or very much reduced. In addition, the inspector noted that the Government’s Planning Practice Guidance states that ‘In general terms, substantial harm is a high test, so it may not arise in many cases’

Taking a precautionary approach and taking into account the highest figure suggested by the county council, the inspector was not of the view that a 5.25 per cent loss of earthworks would result in a substantial physical loss. It was clear that a very high percentage of the earthworks would remain, he reasoned. Further, in terms of group value, not only would the loss be on the edge of a settlement, importantly in his view, it would also be on the very northern edge of the earthworks within the priority township. Consequently, the large area of earthworks to the south of the appeal site would still very much retain their contiguous group value and the proposal would not sever or segregate any wider areas of earthworks.

Overall, given this and other considerations, he concluded that the proposal would result in less than substantial harm to the significance of the priority township.

As we all know, each case must be decided on its own merits, but this case might provide a handy rule of thumb.

The impact of large housing developments on heritage assets is discussed at section 7.1357 of DCP Online.