Ruling confirms conditions for planning permission severability

It can be advantageous for developers to have planning permission that is severable where they intend to deliver their projects in phases and the development takes place over land that is subject to multiple planning permissions. This is especially the case following a 2022 ruling by the UK Supreme Court in the case of Hillside Parks Ltd v Snowdonia National Park Authority, which confirmed the potential for overlapping planning permissions to impact one another – the Supreme Court considered that if implementing one set of planning conditions would make it physically impossible to adhere to an overlapping planning permission, then it could prevent future development across the site, unless the relevant planning permissions were severable.

Jamie Lockerbie of Pinsent Masons said the judgment of the High Court issued on Wednesday in the case of R (Aysen Dennis) v London Borough of Southwark and Notting Hill Genesis (NHG) provides guidance to developers on when different phases of a multi-phase planning permission can be considered properly severable from one another.

In his ruling on Wednesday, Mr Justice Holgate determined that the London Borough of Southwark had acted beyond its power by granting developer Notting Hill Genesis’ application to update outline planning permission it has to redevelop the Aylesbury Estate in Southwark, to explicitly provide that the permission granted is ‘severable’.

In England, section 96A (s.96A) of the Town and Country Planning Act 1990 provides developers with a right to file an application with their local planning authority to amend planning permission they have been granted. The planning authority can grant the application provided the change sought is not ‘material’.

The judge considered that s.96A applications that seek to ensure planning permissions explicitly state that the permissions are ‘severable’ cannot be granted unless the permission is actually severable into component parts in practice.

On 5 August 2015, outline planning permission (OPP) was granted for the redevelopment of a 22 hectre area of the Aylesbury Estate to provide buildings between two and 20 storeys high on 18 development parcels. The scheme comprised three phases known as phases 2, 3 and 4.

In July 2022 NHG submitted an application for detailed planning permission for phase 2B. This application is what is commonly referred to as a ‘drop-in’ or ‘slot-in’ application because it would sit over and supersede part of the OPP. In January 2023, London Borough of Southwark’s Planning Committee resolved to grant the slot-in application for Phase 2B subject to a number of conditions – including that a s.96A application be made to “protect the validity of [the OPP]”.

The required s.96A application was filed in December 2022 and sought to add the word “severable” to the description of development so that it would read “a severable phased development”. The s.96A application was granted in March 2023 under delegated authority and was challenged by local resident Aysen Dennis under a claim for judicial review. Dennis sought to quash the decision on the basis that the change proposed by the s.96A application was material and therefore went beyond what is provided for under the s.96A process. Dennis was successful and the s.96A decision was quashed.

In considering an appeal raised by London Borough of Southwark, Mr Justice Holgate found that “on a true construction the OPP was not severable prior to the s.96A amendment” and therefore using s.96A to add the word “severable” to the description of development “significantly enlarged the bundle of rights granted by that permission”. As such, the judge ruled that “it must follow that this was a ‘material’ amendment of the OPP for the purposes of s.96A of the TCPA 1990”.

In coming to this conclusion Mr Justice Holgate undertook analysis as to whether the OPP was in fact a severable permission. He made reference to numerous of the application documents that in one way or another referenced or supported the concept of “comprehensive regeneration” of the Aylesbury Estate. He ruled: “Because of considerations such as these, and also the variety of ways in which a permission might be severed, it is important that any decision to grant a severed planning permission be expressed unequivocally. Where that is not done, any contra-indications said to support severance must be equally clear.”

Lockerbie said: “The judgment presents a very conservative view on whether the phases of a multi-phase planning permission can properly be said to be severable from one another. In order for a planning permission to be considered as severable into component parts, it must be crystal clear in the application, and consequently on the decision notice, on what basis it is severable, and the application documents – and the associated assessment work etc – need to be carefully drafted to align and be consistent with this position. One thing that is unambiguous is that trying to retrospectively badge a multi-phase scheme as severable when on the facts it is not, is not permissible.”