HCR Law Events

15 February 2023

Court clarifies the scope of section 73 applications to vary existing planning permissions

A common query when considering material amendments to an existing planning permission is whether you can vary such permission by a section 73 application or will a new planning application be required. Helpful guidance in determining this question has been recently provided by the High Court.

Material amendments to planning permission – section 73 applications

Section 73 of the Town and Country Planning Act 1990 allows you to apply to the planning authority for planning permission for the development of land without complying with conditions subject to which an unexpired previous planning permission was granted. If the application is granted then a new planning permission will be issued separate to the previous planning permission which remains valid.  In determining section 73 applications the planning authority shall consider only the question of the conditions in question.

The Government’s Planning Practice Guidance advises that section 73 applications may be used for ‘minor material amendments’ to existing planning permissions and that if any modification of approval proposals are ‘fundamental or substantial’ then a new planning application is required.

Whether the above planning guidance is correct, and generally what is the correct legal scope of section 73 applications, was the issue in the recent High Court decision of Armstrong v Secretary of State for Levelling-up, Housing and Communities & Anor [2023] EWHC 176 (Admin).

In the Armstrong case planning permission had been granted for the ‘construction of one dwelling’ on the Site. The permission then imposed by condition that the authorised development of one dwelling must be constructed in accordance with the approved plans of the design of the dwelling. The owner subsequently submitted a section 73 application to amend such condition by substituting new plans which completely redesigned the dwelling. The council refused the section 73 application deciding that the proposed revised design completely alters the nature of the development and would result in a development that would differ materially from the approved permission. A planning inspector in dismissing an appeal concluded similarly to the council finding that the redesign was not a minor material amendment in accordance with the Government’s planning guidance. The owner statutorily reviewed the inspector’s decision.

Mr James Strachan KC, sitting as a Deputy Judge of the High Court, found that the planning inspector erred in law in his interpretation of the scope of section 73 and quashed the appeal decision. He strongly criticised the misleading and incorrect advice in the Government’s planning guidance stating that it ‘introduces a concept of “minor material amendment” where no such expression exists in the statutory scheme, nor is otherwise supported by the most recent authorities’.

The Deputy Judge in his decision clarified that:

Section 73 is clearly intended to be a provision which enables a developer to make a section 73 application to remove or vary a condition, provided of course that the application does not conflict with the operative part of the planning permission.

But provided there is no inherent conflict or inconsistency with the “operative part” of the planning permission – in this case the construction of a single dwelling – the planning merits of that proposed change can be assessed on its merits. No such assessment has occurred. As part of that assessment, the decision-maker will be able to consider whether the proposed change (fundamental or otherwise) is acceptable or not in planning terms, taking account of any representations received.”

The operative part of the planning permission being the description of the development granted. In the Armstrong case that was the construction of a dwelling on the site for which the Deputy Judge found that the redesign of the dwelling would cause no conflict.


The Armstrong case will likely come as a surprise to practitioners that have followed the Government’s planning guidance and approached section 73 applications as appropriate only for minor amendments. This decision clarifies a much wider scope for such application and may see an increase of its use.

For any assistance or advice in relation to the issue discussed in this article or on any other planning highways and environment issues then please contact HCR’s Planning Highways and Environment Team.

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About the Author
Brendon Lee, Senior Associate, Planning, Highways & Environment

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