Hillside Parks Ltd v Snowdonia National Park Authority

A planning permission for an integrated multi-unit scheme ordinarily cannot be severed into permissions for discrete parts of the site. It authorises each stage while implementation of the whole scheme remains physically possible. If material physical alterations carried out under another permission make the approved scheme impossible, the original permission no longer authorises further development.

This rule concerns physical impossibility, not abandonment, election or retrospective invalidity. Development lawfully completed before the impossibility arose remains lawful. Immaterial departures do not necessarily prevent continued reliance on the permission. A later permission can modify an entire scheme if, objectively construed, it grants permission for the whole site incorporating the changes. Merely describing a local permission as a variation is insufficient.

In 1967 the local planning authority granted full permission for an integrated development of 401 dwellings and roads at Balkan Hill. Only 41 houses were subsequently built, none in accordance with the approved Master Plan. Much of that construction proceeded under later permissions relating to particular parts of the site.

In earlier proceedings, Drake J declared in 1987 that the 1967 development had begun lawfully and could be completed. The present proceedings concerned the legal effect of development carried out after that judgment. HHJ Keyser QC dismissed Hillside Parks Ltd's claim: [2019] EWHC 2587 (QB). The Court of Appeal dismissed its appeal: [2020] EWCA Civ 1440.

The Supreme Court confined the appeal to whether further development could lawfully proceed under the 1967 permission. The res judicata issue was outside the grant of permission to appeal.

1. Disposition. The court unanimously dismissed the appeal. The 1967 permission authorised a single integrated scheme. Material development carried out since 1987 made implementation of that scheme physically impossible, so the permission no longer authorised further development.
2. No abandonment doctrine. Planning permission cannot be extinguished by abandonment. It runs with the land, and only legislation or the permission's own terms can prevent it enuring for the land's benefit. The court approved the reasoning in Pioneer Aggregates (UK) Ltd v Secretary of State for the Environment [1985] AC 132. A subjective intention to retain or abandon a permission is therefore irrelevant.
3. The physical-impossibility principle. Under Pilkington v Secretary of State for the Environment [1973] 1 WLR 1527, the question is whether works actually carried out have made it physically impossible to implement the whole development authorised by the other permission. Mere inconsistency between permissions is insufficient. The terms of the implemented permission are immaterial to this inquiry. A departure must also be material in the context of the approved scheme as a whole; materiality is a question of fact and degree.
4. Multi-unit development. Full permission for a multi-unit development is ordinarily permission for an integrated whole, unless clear language makes it spatially severable. The planning authority cannot normally be taken to have authorised a developer to combine selected parts of the approved scheme with materially inconsistent development elsewhere. F Lucas & Sons Ltd v Dorking and Horley Rural District Council (1964) 17 P & CR 116 was wrongly decided.
5. No retrospective unlawfulness. Permission authorises each stage of an approved development while completion remains feasible. Later failure or inability to complete does not retrospectively make earlier lawful work unlawful. The contrary observations in Sage v Secretary of State for the Environment, Transport and the Regions [2003] UKHL 22 were obiter and could not support such a conclusion. A completion notice under section 94 of the Town and Country Planning Act 1990 operates prospectively.
6. Later permissions. A later permission may, on its true construction, grant fresh permission for the entire site incorporating modifications to an earlier scheme. Ordinarily, however, it must present a coherent design for the whole site. The label “variation” is insufficient by itself. A permission should otherwise be treated as self-contained and independent unless it refers to the earlier permission.
7. Application. The developer did not produce the applications and plans needed to establish that the post-1987 permissions modified the whole Master Plan. Permissions D, G and H were independent local permissions, and permissions A, B and E were not shown to approve a revised whole-site scheme. Their implementation, together with development for which no permission was proved, materially obstructed houses and roads required by the Master Plan. The claim and appeal were therefore dismissed.

1. United Kingdom Supreme Court: In Hillside Parks Ltd v Snowdonia National Park Authority [2022] UKSC 30 , the court unanimously dismissed the appeal and affirmed that no further development could lawfully proceed under the 1967 permission.
2. Court of Appeal: The court dismissed the developer's appeal because post-1987 development had made implementation of the 1967 permission impossible: [2020] EWCA Civ 1440 .
3. High Court: HHJ Keyser QC dismissed the claim, holding that physical alterations since 1987 made full implementation of the 1967 permission impossible: [2019] EWHC 2587 (QB) .
4. High Court in 1987: In earlier unreported proceedings, Drake J declared that the development permitted in 1967 had begun lawfully and could be completed in the future. The present appeal proceeded without challenging that determination.