Published Works | Planning Resource | 12 March 2024

Legal Viewpoint: Just because a consent is phased doesn't mean that drop-in applications are permissible, rules High Court

The High Court ushered in 2024 by handing down its latest in a long line of judgments on overlapping planning permissions, scheme changes and the widely-used practice of “drop-in” permissions. This latest decision, over the phased redevelopment of the Aylesbury Estate in south London, has significant implications for developers and decision-makers involved in formulating development strategies and amending existing schemes.

In March 2023, Southwark Council granted a non-material amendment under section 96A of the Town and Country Planning Act 1990 to insert the word “severable” into the description of development in the outline permission for the regeneration project.

The council and developer argued that the outline permission was ‘severable’ in any event – by virtue of its phases – and that the purpose of the amendment was to make that clear on the face of the permission.

Treating the outline permission as severable would allow the developer to implement a ‘drop-in’ permission to replace an existing phase of development with a new (otherwise incompatible) form of development. In this case, the developer sought to increase housing provision in the development.

The claimant argued that on its true construction the outline permission was not severable and that the amendment to make it severable could not be treated as non-material. This, it argued, was because its purpose and effect was to make the outline permission more flexible, disapplying the Pilkington principle. This was a principle which established that if development carried out under one permission makes it physically impossible to carry out development authorised by another permission, then that consent may no longer be relied upon.

The parties had agreed that, if the outline permission was not already severable, section 96A could not be used to make it so.

The key question for the court concerned the scope of the rights conferred by the outline planning permission, and whether those were changed materially by the section 96A amendment. The Supreme Court had held in Hillside Parks v Snowdonia National Parks Authority [2022] UKSC 30 that overlapping permissions can coexist where the earlier permission was unequivocally granted as a severable consent – and so the answer to this question turned on whether the outline permission was a “severed or severable consent”. 

The council and the developer submitted that the outline permission was severable by virtue of its phases. 

The High Court found that being phased doesn’t, of itself, mean that a permission is severable. Any decision to grant a severed planning permission must be expressed unequivocally. On the facts, the outline permission was a single, indivisible permission, not a severed permission or a collection of freestanding permissions. 

The phasing provided for by the outline permission involved spatially discrete phases which the permission required to be delivered sequentially. The approved design and access statement and design code ran as a thread throughout the permission. None of the underlying application documents contemplated that individual phases might subsequently be replaced by a materially different drop-in application. All of this was found to be compatible with the grant of a single permission and inconsistent with the grant of a severed permission. 

The High Court concluded that the outline permission was not severable before the section 96A amendment. It was a single planning permission with provisions for phasing.

Holgate J also expressed strong reservations about the legality of an amendment to a planning permission which inserts bare language such as “severable” into a description of development without any other indication of the way in which the permission is to be considered severable. Despite the council and the developer arguing that the phasing of the outline permission made it severable, the introduction of the word “severable” wasn’t caveated in that way.

The High Court found that, to the extent that the amendment did sever the outline permission, its effect was to disapply the Pilkington principle. This made it unnecessary to apply the physical impossibility test to a future material departure from the development authorised by the outline permission. This significantly enlarged the “bundle of rights” conferred by the permission, and was a material amendment of the outline permission that went beyond the powers in section 96A. The claim was allowed and the purported non-material amendment to the outline permission quashed.

The decision in Dennis gives rise to some significant – and challenging – implications for those involved in significant regeneration and redevelopment schemes. As the dust settles, the development industry will welcome the government’s March 2024 consultation which seeks views on whether legislative intervention could form the basis of a solution.

Case: R (Aysen Dennis) v LB Southwark and Notting Hill Genesis 

Date: 17 January 2024

Ref: [2024] EWHC 57 (Admin) 

This article first appeared in Planning Resource (12 March 2024)

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