The cost of specificity – The substantial scope of section 73 planning permissions

In a recent decision of the Court of Appeal on 10 December 2024, the court provided clarity on the scope of section 73 planning permissions in a case that found against the solar farm developer who had sought to change the size and location of the substation after the original planning permission had been granted.

Test Valley Borough Council and Fiske [2024] EWCA Civ 1541

Section 73 of the Town and Country Planning Act 1990 can be used to vary the conditions of a planning permission after it has been granted, usually where various details about the site have changed over time. However, a central feature of section 73 is that it is used to vary the conditions of a planning permission and not the operative part (the main description of the permitted development). In fact, a section 73 application stands as its own separate planning permission, with applicants entitled to choose which permission to implement, as a section 73 application does not supersede a previous application.

The developer in the case had obtained full planning permission in 2017, and the operative part of that permission included in its description reference to a 'substation' in accordance with the approved plans, which included a drawing detailing a 33kV substation. Consequently, this 33kV substation was understood to form part of the main 'operative' part of the planning permission. The developer later sought to vary the conditions using section 73, introducing a new 132kV substation and omitting reference to the original substation. A challenge was brought against the council's decision by a local resident, Mrs Chala Fiske, that section 73 had been mis-applied. The High Court agreed with Mrs Fiske, stating that section 73 could not be used to make fundamental changes to a planning permission. Test Valley Borough Council consequently appealed to the Court of Appeal resulting in this judgement. While the Court of Appeal reached the same overall decision as the High Court, it differed in its interpretation of the operation of section 73.

The judge in the case dismissed the appeal on the basis that the developer had sought to use section 73 to alter the operative part of a full planning permission and that this was not possible under the legislation. Consequently, because the developer had chosen to specify the inclusion of the 33kV substation in its description of the development, it was not possible to retrospectively change this.

Crucially, the judge also confirmed that it is possible to make both substantial and fundamental changes under section 73, as long as they do not alter, or conflict with, the operative part of the planning permission. This has provided much needed clarification to the legal position, as the High Court decision in Fiske had stood in contradiction to other recent judgements, such as Armstrong v Secretary of State for Levelling-Up, Housing and Communities [2023] EWHC 142 (KB), by asserting that substantial changes could not be made to a planning permission using section 73. This recent Court of Appeal decision confirms that substantial changes are permittable, providing they are not inconsistent with the operative part of the planning permission.

Our thoughts

The cautionary tale for developers is to ensure that the description of the development when submitting a planning application is as broad and flexible as possible in order to allow greater scope for changes down the line. Specificity, in this case, could be costly.

It is also particularly relevant for developers to bear in mind that with the surge in development across the country, spearheaded by the new Labour government, they are increasingly likely to encounter opposition from highly motivated local residents scrutinising applications for anything that may be used to de-rail the development. Consequently, to avoid the cost and delay of challenge, the planning process will need to be followed to the strict letter of the law.