Dennis vs Southwark: A warning on amending planning permissions in phased developments

Judgment was handed down yesterday in the High Court, in favour of council tenant and housing campaigner, Aysen Dennis, in her case against the London Borough of Southwark. Ms Dennis is a long-time resident of the Aylesbury Estate, which has been undergoing significant redevelopment since 2015. She challenged Southwark Council’s decision to allow housing provider Notting Hill Genesis to amend a planning permission, making it easier to push through changes to the original ‘masterplan’, without applying for new planning permission.

What is the background to Dennis vs Southwark?

The Aylesbury Estate dates back to the 1960s. In 2010 Southwark Council put forward a ‘masterplan’ to redevelop the site over a 20 year period, to increase the number of houses and flats, which would accommodate a mixture of social and private housing.

In 2014, Southwark partnered with Notting Hill Housing Trust (which later became Notting Hill Genesis) to deliver on the remainder of the phased development of the estate. As part of this, in August 2015, Southwark granted ‘outline planning permission’ to Notting Hill Genesis, which included phase 2 of the redevelopment, to take place between 2016 – 2025.

However, in 2022, Southwark Council introduced a new ‘Southwark Local Plan’, which stated it was necessary to increase the number of new homes originally planned for the redeveloped Aylesbury Estate in the 2015 outline planning permission.

This led to Notting Hill Genesis applying for a non-material amendment (under section 96A of the Town and Country Planning Act 1990) to the original outline planning permission – often referred to as a ‘drop-in’ application. The application was granted by Southwark in March 2023. This amendment added the word ‘severable’ to the planning permission. Treating the outline permission as ‘severable’ would allow Notting Hill Genesis to carry out, under a new planning permission, a phase of the redevelopment (such as changing building height) which is physically incompatible with the authorisation conferred by the outline permission, without losing the right to carry out further phases under the outline permission.

The impact of the Pilkington principle and Hillside Parks Ltd vs Snowdonia National Park Authority

Ms Dennis claimed that the amendment to make the outline planning permission severable was, in fact, ‘material’ and as such outside of section 96A. She claimed that “the purpose and effect of the amendment is to change the bundle of rights granted by the outline planning permission, so as to disapply the Pilkington principle (Pilkington v Secretary of State for the Environment [1973] 1WLR 1527).”

The Pilkington principle may arise where two or more planning permissions have been granted on the same area of land and development has been carried out under one of those permissions. If that [later] development has made it physically impossible to carry out development approved by another [earlier] consent then that [earlier] consent may no longer be relied upon.

Ms Aysen also claimed that as the original outline planning permission was not severable, an entirely new planning permission is needed for the entire scheme, as suggested by the Supreme Court’s judgment in Hillside Parks Ltd v Snowdonia National Park Authority 2022.

The outline planning permission provided for a phased development and Southwark and Notting Hill Genesis (as an interested party) argued that the phases were individually authorised by the permission, such that the permission was, in practical terms, severable. They also ascertained that “the amendment made under s.96A was only intended to confirm that position explicitly on the face of the consent.”

Mr Justice Holgate’s ruling in Dennis vs Southwark

The Judge, Mr Justice Holgate, disagreed with Southwark and Notting Hill Genesis. He stated that the outline planning permission remained a single permission, whereas to be severable, there would have to have been a grant of “several separate permissions”. As such, it could not be amended through a non-material application.

In terms of the Pilkington principle, he said: “this case is not concerned with establishing in what circumstances Pilkington would prevent reliance upon the outline planning permission or, more generally, a phased outline planning permission. The only issue is whether Southwark and Notting Hill Genesis are correct to assert that, as a matter of interpretation, the outline planning permission was a severed permission in any event and that the s.96A amendment was simply made in order to confirm that position in express terms.”

In granting Ms Dennis’s challenge, Mr Justice Holgate added that he had “strong reservations about the legality of an amendment to a planning permission which simply inserts language as uncertain as the bare term ‘severable’. There was nothing to indicate the extent to which the outline planning permission was purportedly severed. For a large-scale development it would have been possible to conceive of many different alternatives.”

What are the implications for developers wishing to amend planning permission?

The ruling is important to developers, lenders, landowners and prospective purchasers alike, where there are several ‘layered’ permissions across a site which are inconsistent.

It follows on from the recent Supreme Court judgment in Hillside Parks Ltd v Snowdonia National Park Authority, which clarified that planning permission to develop a plot of land is not severable, unless the permission specifies that it is.

This ruling takes that one step further, in stating that in this case, an s96A amendment cannot be used to retrospectively apply severability.

As the Public Interest Law Centre, which was representing Ms Aysen, commented: “This judgement should serve as a warning to developers who disregard historical masterplans.”

Any interested party who is considering applying for an amendment to planning permission as part of a phased development with ‘layered’ planning permission should ensure they take expert legal advice before acting.