In Hillside Parks Ltd v Snowdonia National Park Authority [2022] UKSC 30; [2022] PLSCS 177, the Supreme Court unanimously dismissed an appeal that brought the issue whether successive planning permissions for parts of a wider site (also known as “drop-in” permissions) render the original permission unimplementable.
In 1967, a planning permission was granted for a large housing development in Balkan Hill, Aberdyfi in Snowdonia National Park. The approved buildings and roads were identified in the masterplan. Eight additional planning permissions were granted between 1967 and 1974.
In 1985, High Court proceedings started. Drake J’s judgment ([2019] EWHC 2587 (QB)) granted declarations providing that the development pursuant to the 1967 permission could be lawfully completed in the future.
Once Snowdonia National Park Authority became the local planning authority for the site, it granted eight further permissions between 1996 and 2011. Development was carried out at the site pursuant to the permissions granted after the 1967 permission. However, in 2017, Snowdonia informed Hillside Parks that it was no longer possible to implement the 1967 permission, because it was impossible to build the development in a manner consistent with the 1967 masterplan.
The landowner made a Part 8 CPR claim seeking declarations that: 1) Snowdonia was bound by the declarations of Drake J; 2) the 1967 permission is valid; and 3) the development may be carried out under the 1967 permission. The High Court considered that Drake J’s declaration was not wrong in law, but agreed it was no longer possible to lawfully carry out development under the 1967 permission, as it was physically impossible to follow the 1967 masterplan. The case was appealed, but the Court of Appeal confirmed the High Court’s ruling ([2020] EWCA Civ 1440; [2020] PLSCS 199). The case was further appealed to the Supreme Court.
The Supreme Court acknowledged that no legislative provision regulates the situation where two or more planning permissions granted for development on the same site are mutually inconsistent. Instead, Pilkington v Secretary of State for the Environment [1973] 1 WLR 1527 provided that, where the development carried out based on the second permission is incompatible with the first permission, then the first permission can no longer be relied on as authorising further development.
In its judgement, the Supreme Court focused on the following matters. First, Pilkington is based on the “physical impossibility” of carrying out the unimplemented permission, as opposed to a “mere incompatibility with the terms of another permission already implemented”. Secondly, based on Sage v Secretary of State for the Environment, Transport and the Regions [2003] UKHL 22; [2003] 1 PLR 121, failure or inability to complete a project for which planning permission was obtained “does not make development carried out pursuant to the permission unlawful”. Thirdly, an unimplemented permission only becomes physically impossible to implement if the departure is “material in the context of the scheme as a whole”. Fourthly, planning permission for multi-unit developments is usually an “integrated scheme which cannot be severed into component parts”, unless the permission has a “clear express provision making it severable”.
The Supreme Court concluded that the 1967 permission was granted for a single scheme. The additional planning permissions constituted separate permissions referable to just parts of the scheme, as they were not construed as a modification of the entire scheme. For that reason, the development of these additional permissions was “inconsistent with the 1967 permission and has had the effect that it is physically impossible to develop the Balkan Hill site in accordance with the masterplan approved by the 1967 permission”.
The judgment also hinted that rather than proceeding with drop-in consents, the correct approach would be to seek for “appropriately framed additional planning permission which covers the whole site and includes the necessary modifications”.
This case reaffirms the Pilkington principle, but with the considerations mentioned above. This clearly affects multi-unit developments, which tended to rely on drop-in permissions.
Stefano D’Ambrosio is a solicitor in the planning and environmental team at Irwin Mitchell
